JPH01169170A - Variable displacement torque converter - Google Patents

Abstract

PURPOSE:To obtain the characteristic in accordance with an operating condition and a running condition or the like by providing a reaction force member, brake means enabling this reaction force member to be connected further brake torque to be changed continuously or in multiple steps and a control unit regulating the brake torque by this brake means. CONSTITUTION:Brake torque of a brake means 16 is controlled by duty ratio of a signal given to a solenoid valve 19. This duty ratio is increased, when a reaction force member 15 is fixed, a stator 13 is fixed through a one-way clutch 14, and torque is transmitted by predetermined torque ratio determined by a design. While the duty ratio is set to zero, when the stator 13 is raced, the stator torque decreases to zero, and a torque converter performs no torque increase, acting as the fluid coupling. Further setting the duty ratio to a suitable value and decreasing the brake torque of the brake means 16, thus by slip controlling the brake means 16, when the brake torque is adjusted, the stator torque is set to a value in accordance with the brake torque.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a torque converter that transmits torque from a drive source via fluid, and for example, a torque converter disposed between an engine and an auxiliary converter 411 h'4 in a vehicle. It concerns converters.

Conventional technology A typical torque converter installed in a vehicle with an automatic transmission has a one-way transmission between a pump impeller connected to the engine and a turbine runner that rotates in response to the fluid flow generated by the pump impeller. The stator is arranged via a clutch, and when the ratio of rotational speeds (speed ratio) between the pump impeller and the turbine runner is below a predetermined value, the fluid flow from the turbine runner to the pump impeller hits the stator. By changing the direction of the stator, the transmitted torque increases, and when the speed ratio exceeds a predetermined value, the stator begins to rotate, so the torque is not increased and the stator functions as a mere fluid coupling.

, FIG. 6 is a diagram showing the characteristics of a conventional general torque converter, and point P is clutch point 1 which is the boundary between the converter range and the coupling range.

By the way, a torque converter transmits torque through fluid, so it absorbs shock and vibration, but it also allows relative rotation between the pump impeller and turbine runner, so its efficiency is slightly lower. Since torque is constantly transmitted and the torque ratio is highest when the speed ratio is zero, if the auxiliary gear change IN mechanism is set to the drive range, for example, a creep phenomenon may occur where the vehicle starts to move naturally. There's a problem. Therefore, various torque converters have been proposed in the past, which have various improvements added to the above-mentioned general configuration.

For example, in Japanese Patent Application Laid-open No. 58-156771, as shown in FIG. Connected to 5,
When the vehicle is stopped, the hydraulic servo 4 is communicated with the reservoir 7 by the switching valve 6 and the brake 5 is released, thereby allowing the stator 2 to rotate freely, thereby causing the torque converter 1 to function as a mere fluid coupling, and as a result, A device configured to prevent the creep phenomenon and vibration during suspension is described.

Furthermore, Japanese Patent Application Laid-Open No. 52-24662 discloses that a clutch is provided between the pump impeller and the stator, and when the vehicle is running at a high speed, the clutch is engaged to integrate the pump impeller and the stator. A device is described that improves efficiency by preventing losses due to fluid flow rotating the stator.

Furthermore, in Japanese Patent Application Laid-open No. 52-25972, the stator is divided into two in the axial direction, and the part near the pump impeller can be idled and fixed, and one of the divided stators is divided into two parts in the axial direction. Let the stator idle,
Alternatively, a variable capacity torque converter configured to maximize the engine's capacity by fixing the converter is described.

Also, Japanese Patent Application Laid-open No. 50-66658 and Utility Model Application No. 53-2
No. 79 discloses a structure in which a clutch is provided between the stator and a predetermined fixed part, and by engaging or disengaging the clutch, the stator is idled or fixed, thereby obtaining different characteristics. The @ position is written.

Problems to be Solved by the Invention However, in a membrane torque converter, when the speed ratio is small, the stator is fixed by the one-way clutch, so the transmitted torque increases, and the speed ratio increases and the clutch When the stator starts spinning by reaching the clutch point, the torque does not increase and it functions as a fluid coupling, and the clutch point maintains a constant speed ratio determined by design. In a torque converter, the stator is idled due to so-called external factors such as engine load and driving conditions.
Otherwise, it will be fixed, so essentially the clutch point will be artificially changed. In other words, in the device described in the above-mentioned Japanese Patent Application Laid-Open No. 58-156771, the brake is released while the vehicle is stopped and the stator is idled, so the stall point where the torque ratio is highest is eliminated and the clutch point is moved to the speed ratio. This means that it has moved to the zero point, and in this state it functions completely as a mere fluid coupling, and when the brake is engaged and the stator is fixed, the torque ratio will be 11n at the clutch point determined by the design, The torque ratio becomes the largest at the stall point where the speed ratio is zero. If such a characteristic is shown in a diagram as shown in Figure 6, if the brake is engaged,
As shown by the solid line, it has the same characteristics as a general torque converter, whereas if the brake is released, it has the characteristics as a fluid coupling, as shown by the broken line. Therefore, it works well in eliminating creep and vibration when the vehicle is stationary, but since the characteristics are changed in two ways, it is not possible to obtain characteristics suitable for the various conditions in which the vehicle is placed. If the brake is released when the vehicle stops in the middle of a slope and the characteristics of the fluid coupling are used, the vehicle will not be able to remain stopped due to insufficient torque, and conversely, the brake will be engaged to fix the stator. Therefore, when the characteristics are used as a torque converter, the large torque ratio causes problems such as creep and vibration of the vehicle body.

This situation is the same for each of the devices described in the above-mentioned publications, and the devices described in all of the publications either have a fixed stator, or are idling or integrated with a pump impeller. Since the characteristics that can be obtained are two different, it is not necessarily possible to obtain characteristics suitable for each of the various situations and driving conditions in which the vehicle is placed. However, there was still room for improvement in terms of driving performance and ride comfort.

This invention was made against the background of the above.
It is an object of the present invention to provide a variable capacity torque converter that can obtain characteristics depending on operating conditions, running conditions, etc.

Means for Solving the Problems In order to achieve the above object, the present invention provides a so-called slip controllable brake means for setting the stator in various states between fixed and idling. More specifically, the present invention provides a pump impeller that rotates to generate a fluid flow and a turbine runner that rotates in response to the fluid flow from the pump impeller and from the turbine runner. In a torque converter in which a stator is rotatably disposed during a fluid flow toward a pump impeller, a reaction force member that applies a load to the stator in a direction to fix the stator, and a reaction force member that is connected to and braked. It is characterized by comprising a brake means that can change the torque continuously or in multiple stages, and a control device that adjusts the braking torque by the brake means.

The relationship between the torques in the working torque converter is as follows: Pump torque is ■P1 Turbine torque is D1, Stator torque is T
Assuming that S, Tt = Tp + Ts, and in this invention, TS changes depending on the braking torque of the brake means, and therefore, the turbine torque T1 changes in various ways. In other words, when the reaction member is completely fixed by the brake means, the stator acts completely, resulting in characteristics similar to those of a conventional general torque converter.On the other hand, when the brake means is completely released, the stator idles, resulting in the same characteristics as a conventional torque converter. The stator torque TS becomes zero, so the torque is no longer increased, and it has the characteristics of a mere fluid coupling. If the braking torque is adjusted by slip-controlling the braking means in the converter range, the stator torque is set to a value corresponding to the braking torque, so the turbine torque maximizes the torque when the stator is fixed. It is set arbitrarily between the minimum pump torque and the minimum pump torque. As a result, for example, when a vehicle is stopped in the middle of an uphill slope, by controlling the brake means to slip and lowering the turbine torque somewhat, it is possible to prevent not only the vehicle from moving backwards but also from moving forward due to creep, and furthermore, it can prevent vibrations in the vehicle body. can be suppressed.

Example Next, an embodiment of this defense will be described with reference to the drawings.

FIG. 1 is a schematic diagram that basically accepts one embodiment of this explanation, and shows that a torque converter 10 includes a pump impeller 11, a turbine runner 12 disposed opposite to the pump impeller 11, and a pump impeller 11. Turbine runner 12
The stator 13 disposed in the fluid flow from the turbine runner 12 to the pump impeller 11 and the stator tacho 3 are attached between the one-way clutch 14 and the one-way clutch 14 opposite to the member to which the stator 13 is attached. Attach the member (for example, inner race); reaction member 15
and a brake means 16 for braking J5 of the reaction force member 15 and releasing the brake J5.

The brake means 16 can set the braking torque arbitrarily, and for example, a piston is accommodated in a cylinder so as to be movable in the backward direction, and a return spring is provided to push back the piston (or a hydraulic servo of a well-known configuration is provided). It is composed of a wet multi-disc brake, and the degree of engagement, that is, the braking torque, is adjusted by the hydraulic pressure supplied to the ?III servo.Brake means 16
The control device 17 that controls the oil pressure supplied to the engine has a central processing unit (CPU) 18, a solenoid valve 19, and a control valve 20. It is configured to perform calculations based on various signals such as rotation speed and engine temperature, and output a pulse signal with a duty ratio according to the calculation results to the electromagnetic valve 19, and the electromagnetic valve 19 is supplied from a predetermined hydraulic pressure source. The control valve 20 is configured to adjust the constant pressure to a signal pressure according to the input duty ratio and apply it to the control valve 20.
The iIJfa valve 20 is configured to regulate a constant pressure or line pressure supplied from a predetermined hydraulic pressure source to a control hydraulic pressure according to a signal pressure applied from the solenoid valve 19, and supply the control hydraulic pressure to the brake means 16. Note that the solenoid valve 19 can generate oil pressure according to the current value, or can be replaced with a near-made valve.

The pump impeller 11 is connected to a herring output shaft 21, and the turbine runner 12 is connected to a planetary gear R.
It is connected to the input shaft 23 of the auxiliary transmission n11422, which mainly includes II4, a plurality of clutches, and brakes.

Therefore, in the above-mentioned torque converter 10, for example, if the duty ratio of the signal given to the wI magnetic valve 19 is increased to increase the signal pressure supplied to the control valve 20, the control oil pressure supplied to the brake means 16 will be increased. On the contrary, if the duty ratio is made smaller, the signal pressure becomes lower and the brake means 16 receives 1IilJtl.
1 because the oil pressure is low! Duty ratio Cd of magnetic valve 19
The relationship between this and the IIIJIII hydraulic pressure supplied to the brake means 16 is proportional as shown in FIG. on the other hand,
Since the brake means 16 has an engaging force, that is, braking torque, which changes depending on the supplied hydraulic pressure, the brake means 16 eventually
The braking torque is controlled by the duty ratio of the signal given to the solenoid valve 19. Furthermore, the relationship between the torques of the pump impeller 11, the turbine runner 12, and the stator 13 is Tt-Tρ+Ts, as described above, but since the stator torque TS is the braking torque in the brake means 16, the duty is If the reaction force member 15 is fixed by increasing the ratio, the stator 1 is connected via the one-way clutch 14 in the converter range.
3 is fixed, and as a result, torque is transmitted at a predetermined torque ratio determined by design, similar to conventional general torque converters.

On the other hand, if the duty ratio is set to zero and the stator 13 is rotated idly, the stator torque TS becomes zero and the torque is not increased, and as a result, it acts as a fluid coupling. by roughly setting the duty ratio to an appropriate value.

If the braking torque is lowered and thereby the brake means 16 is controlled to slip, the stator torque Ts becomes somewhat lower than when the stator 13 is fixed, so the turbine torque Tt decreases by that amount, that is, the torque ratio decreases. It will be done. Since the degree of reduction depends on the braking torque of the brake means 16, the torque ratio eventually becomes smaller than that of the stator 13.
It is set arbitrarily within a range where the maximum value is the state in which the stator 13 is fixed and the minimum value is 1", that is, the state in which the stator 13 is freely rotated. Such characteristics are shown in a diagram as shown in Fig. 3. , the torque ratio and the capacity coefficient can be changed within the shaded range in FIG.

Therefore, for example, when the vehicle is stopped on an uphill slope, as shown in Figure 4, it is first determined whether the vehicle is in the drive (D) range or not, and if the result is "yes", it is determined whether the vehicle is moving backward. If the result is "yes", increase the duty ratio cd slightly (ΔCd) (Cd+Δ
Cd) can be controlled. By making this kind of control possible, it is possible to set the turbine torque to a level low enough to prevent the vehicle from moving backwards depending on the gradient of the slope, and as a result, it is possible to prevent forward movement due to creep and suppress vehicle body vibration. can.

Effects of the Invention As is clear from the above description, the torque converter of the present invention substantially holds the stator with a brake means that can continuously change the braking torque, and adjusts the braking torque with a control device. Because it is configured to
It is now possible to change the torque ratio and capacity coefficient steplessly or in multiple steps, and as a result, the optimum torque ratio and 8 suspensions can be set according to the vehicle's driving conditions and driving conditions. Accordingly, the driving performance of the vehicle can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the principle of an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between the duty ratio of the solenoid valve and the control oil pressure supplied to the brake means, and Fig. 3 is a characteristic diagram. , 4th
The figure is a flowchart showing an example of control on an uphill slope.
The figure is a schematic diagram showing the configuration described in Japanese Unexamined Patent Publication No. 58-156771, and FIG. 6 is a characteristic diagram thereof. DESCRIPTION OF SYMBOLS 10... Torque converter, 11... Pump impeller, 12... Turbine runner, 13... Stator, 15... Reaction member, 16... Brake means, 17... Control device, 18 ...CPU, 1
9... Solenoid valve, 20... Control valve. Applicant Toyota Motor Corporation Representative Patent Attorney Yutaka 1) Substitution (one idiot) Figure 1 Figure 2

Claims (1)

[Claims] A stator is provided between a pump impeller that rotates to generate a fluid flow and a turbine runner that rotates in response to a fluid flow from the pump impeller, and during a fluid flow from the turbine runner to the pump impeller. A torque converter rotatably arranged, a reaction member that applies a load to the stator in a direction to fix the stator, and a brake that is connected to the reaction member and that can change braking torque continuously or in multiple stages. 1. A variable capacity torque converter, comprising: a means for braking; and a control device for adjusting braking torque by the braking means.