JPH05296344A - Coreless torque converter - Google Patents

Abstract

PURPOSE:To improve both the torque ratio in the low speed ratio area and capacity in the high speed ratio area in a coreless torque converter not having a core in a section where impellers are collected. CONSTITUTION:A movable stator 9 is provided, which makes the clearance 10 between an pump impeller 2 and the movable stator 9 large in the low speed ratio area side and makes the clearance 11 between a turbine runner 5 and the movable stator 9 large in the high speed ratio area side. The movable stator 9 is supported by a spline slide mechanism 12 having a return spring 12 which changes a relative position utilizing that the flow direction of circular flow varies according to speed ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coreless torque converter which does not have a core in a portion where each blade is assembled.

[0002]

2. Description of the Related Art Conventionally, as a coreless torque converter, for example, one described in SAE Paper 861213 is known.

In this conventional source, as shown in FIG. 7, a pump impeller 01, a turbine runner 02, and a stator 03 are provided.
There is shown a coreless torque converter called a three-element two-phase type which has elements and has no core in a portion where each of these blades is assembled.

[0004]

However, in such a coreless torque converter, a member that restricts a flow and forms a flow path corresponding to the core of a torque converter applied to a general passenger car. As shown in FIG. 8, since the center of the vortex of the circulating flow is biased toward the turbine runner side, the stall torque ratio and efficiency are lower than those of the torque converter with a core, making it difficult to apply to vehicles with small displacement. In addition, there is a problem that fuel efficiency deteriorates under running conditions in which the vehicle is repeatedly started and stopped.

Therefore, the present applicant has filed Japanese Patent Application No. 2
-199877 proposed a coreless converter in which the axial clearance between the stator and the pump impeller is set larger than the axial clearance between the stator and the turbine runner.

According to this coreless converter, the stall torque ratio increases, but the capacity tends to decrease. Therefore, the torque ratio at the time of starting, which is a low speed ratio, increases and the starting acceleration improves, but Since the capacity is small in the speed ratio, there is a problem in that the intermediate acceleration is not good, the slip increases, and the fuel efficiency deteriorates.

The present invention has been made by paying attention to the above-mentioned problems, and in a coreless torque converter having no core in the portion where each blade is assembled, the torque ratio is improved and the torque ratio is improved in a low speed ratio region. The first problem is to achieve both capacity improvement in the speed ratio region. A second object is to achieve the first object while making the cost and maintenance advantageous.

[0008]

In order to solve the first problem, in the coreless torque converter according to the first aspect, the clearance with the pump impeller is maintained on the low speed ratio region side, and the turbine is maintained on the high speed ratio region side. In order to maintain the clearance with the runner, a movable stator whose relative position changes according to the speed ratio is provided.

That is, in a coreless torque converter having three elements of a pump impeller, a turbine runner, and a stator, and having no core at a portion where these blades are gathered, the stator is formed to have a short axial dimension. In order to maintain the clearance with the pump impeller on the low speed ratio region side and the clearance with the turbine runner on the high speed ratio region side, the movable stator whose relative position changes according to the speed ratio is characterized.

A second aspect of the present invention is provided to solve the second problem.
In the coreless torque converter described in claim 1, in the coreless torque converter according to claim 1, the movable stator is supported by a movable mechanism that changes a relative position by utilizing a fact that a flow direction of a circulating flow changes according to a speed ratio. Is characterized by.

[0011]

[Operation] The operation of the invention of claim 1 will be described.

During operation in the low speed ratio region, the movable stator is biased toward the turbine runner side, and a clearance is maintained between the movable stator and the pump impeller, so that flow occurs between the movable stator and the pump impeller. The free flow path with low resistance is provided, and the oil circulating inside easily flows out from the trailing edge of the movable stator, and the flow that passes through the upper end of the movable stator and flows into the pump impeller or turbine runner is suppressed. The movable stator with the torque increasing function works effectively.

That is, the center of the vortex of the circulation flow is biased toward the turbine runner side when the free flow passage is not set. However, the center of the vortex of the circulation flow shifts toward the pump impeller side due to the setting of the free flow passage, The flow pattern becomes closer to the center of the torus.

During operation in the high speed ratio region, since the movable stator is biased toward the pump impeller side and a clearance is maintained between the movable stator and the turbine runner, flow between the movable stator and the turbine runner occurs. Since the free flow path having a small resistance is provided, the strong circulating flow is separated from the movable stator, and the circulating flow rate that determines the capacity increases.
The operation of the invention according to claim 2 will be described.

Looking at the flow direction of the circulating flow during operation of the torque converter, in the low speed ratio region, the flow direction at the inlet of the stator collides with the lower surface of the stator blades, and the higher the speed ratio, the more the direction. Shows the change in the flow direction, as the direction changes along the wing.

Therefore, by supporting the movable stator to the movable mechanism that utilizes the fact that the flow direction of the circulating flow changes according to the speed ratio as described above, the speed ratio can be detected by the actuator that drives the stator. It is possible to change the relative position of the movable stator according to the speed ratio without performing stator drive control such as outputting a drive command based on the above.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the structure will be described.

FIG. 1 is a sectional view showing the coreless torque converter of the first embodiment.

The coreless torque converter of the first embodiment is provided with a pump impeller 2 connected to a converter cover 1 to which engine driving force is input, and a pump impeller 2 arranged at a position opposite to the pump impeller 2. A transmission input shaft 3 has a turbine hub. A turbine runner 5 connected via 4;
It has three elements, that is, a movable stator 9 which is arranged in an inner diameter portion sandwiched between the pump impeller 2 and the turbine runner 5, and is supported by a stator shaft 7 via a one-way clutch 6 and a spline slide mechanism 8. The portions where the blades 2, 5 and 9 are gathered have the blade tips close to each other and do not have a core.

The pump impeller 2 and the turbine runner 5
Has the same shape as that used in the conventional coreless torque converter shown in FIG.

The movable stator 9 is designed on the basis of the stator shown in FIG. 7. The blade shape on the pump impeller 2 side is cut away from the conventional shape shown by the one-dot chain line in FIG. It has a flat shape with a shorter length.
The movable stator 9 has a larger number of stator blades than the conventional fixed stator because the blade area per sheet is smaller.

The inner ring of the one-way clutch 6 has a spline cut obliquely to the ring axis, and the stator shaft 7 has a spline cut obliquely to the shaft axis. The spline slide mechanism 8 is configured by spline-connecting both splines with each other. Further, a return spring 12 for pressing the one-way clutch 6 and the movable stator 9 toward the turbine runner 5 side is interposed between the pump impeller 2 and the one-way clutch 6.

As shown in FIG. 2A, the spline is cut diagonally with respect to the shaft axis of the stator shaft 7, and the spline and the movable stator 9 are cut.
The positional relationship with and has the relationship shown in FIG.

That is, the movable stator 9 maintains the clearance 10 between the movable stator 9 and the pump impeller 2 by the pressing force of the return spring 12 in the low speed ratio region, and the spline connection position is increased as the speed ratio increases. It changes to the right in the drawing, and is configured to maintain a clearance 11 between the movable stator 9 and the turbine runner 5 in the high speed ratio region. That is, the spline slide mechanism 8 and the return spring 12 formed between the one-way clutch 6 and the stator shaft 7.
And correspond to the movable mechanism in the first embodiment.

Next, the operation will be described.

From its structure, the coreless torque converter is a modification of the fluid coupling in which only the pump impeller and the turbine runner are arranged to face each other.
It is considered that the internal fluid flow also shows a flow similar to that of the fluid coupling.

According to Fig. 2/11 on page 23 of the previously published "Design of Fluid Transmission" (Tomoo Ishihara et al., Published by Ohmsha in 1967), both medium speed ratio and low speed ratio are circulating flow in fluid coupling. The center of the vortex is biased toward the turbine runner side. It should be noted that the situation where the liquid phase and the gas phase are separated at a high speed ratio is such that in the case of a normal torque converter (including coreless), the inlet pressure is
It does not occur because it is set to about 4 kg / cm ² .

Therefore, in the case of the coreless torque converter as shown in FIG. 7, the circulating flow shown in the flow pattern of FIG. 8 is obtained by analogy with the circulating flow in the fluid coupling. That is, a considerable part of the flow that has flowed into the movable stator passes through the upper end of the movable stator and flows into the pump impeller or turbine runner. This causes the torque ratio and efficiency to be low.

On the other hand, in the coreless torque converter of the first embodiment, in the low speed ratio region, as shown in FIG.
As shown in, the circulating flow acts on the movable stator 9 at a substantially right angle at the inlet of the movable stator 9, so that no force acts in the spline direction and the movable stator 9 is pressed against the return spring 12 and A clearance 10 is set between the pump impeller 2 and the pump impeller 2. As a result, a free passage having a small flow resistance is provided between the movable stator 9 and the pump impeller 2, and the oil circulating inside easily flows out from the trailing edge of the movable stator 9,
The flow that passes through the upper end of the movable stator 9 and flows into the pump impeller 2 or the turbine runner 5 is suppressed, and the movable stator 9 having the torque increasing function works effectively.

That is, as shown in the flow pattern of FIG. 4, the center of the vortex of the circulating flow is closer to the pump impeller 2 side than in the case of FIG. 8 and is closer to the center of the torus.

Then, in the medium speed ratio region, as shown in FIG.
As shown in (b), the circulating flow acts obliquely on the movable stator 9 at the inlet of the movable stator 9, so that the force S acts in the spline direction, and the movable stator 9 resists the force from the return spring 12. It shows an action of being biased to the pump impeller 2 side, that is, the movable stator 9 changes its relative position from the turbine runner 5 side to the pump impeller 2 side as the speed ratio increases.

Further, in the high speed ratio region, as shown in FIG.
As shown in (c), the circulating flow acts at the inlet of the movable stator 9 substantially parallel to the movable stator 9.

As a result, the movable stator 9 is pressed against the pump impeller 2 side against the spring 12, and the clearance 1 is provided between the movable stator 9 and the turbine runner 5.
Since 1 is set, the movable stator 9 and the turbine runner 5
A free flow path having a small flow resistance is provided between the flow path and, and a strong circulating flow is separated from the movable stator 9, and the circulating flow rate that determines the capacity increases.

As described above, in the coreless torque converter of the first embodiment, the effects listed below can be obtained.

(1) In order to maintain the clearance 10 with the pump impeller 2 on the low speed ratio region side and maintain the clearance 11 with the turbine runner 3 on the high speed ratio region side, the shaft whose relative position changes according to the speed ratio Since the flat movable stator 9 is provided in the direction, both improvement of the torque ratio in the low speed ratio region and improvement of the capacity in the high speed ratio region can be achieved.

As a result, the invention can be applied to a vehicle with a small displacement, and the power performance (good starting acceleration and intermediate acceleration) and fuel efficiency of the applied vehicle are improved.

As a result, when applied to a vehicle, it is possible to provide a coreless torque converter which has good starting acceleration and intermediate acceleration and achieves high fuel efficiency.

Incidentally, the flatness of the stator L ₁ / L _{0 is} shown in FIG.
(See Fig. 1), L ₁ / L ₀ = 1.0 (conventional structure), L ₁ / L ₀ =
The performance test results of the coreless torque converter with 0.8 and L ₁ / L ₀ = 0.6 are shown. In the case of the first embodiment, it can be seen that in the low speed ratio region where the clearance 10 with the pump impeller 2 is maintained, the torque ratio characteristic is L ₁ / L ₀ = 0.6, and a high torque ratio can be obtained. In addition, in the high speed ratio region where the clearance 10 with the pump impeller 2 is the minimum, the capacity characteristic is approximately L ₁ / L ₀ = 1.0, and it can be seen that a high capacity is obtained.

(2) Since the movable stator 9 is supported by the movable mechanism including the spline slide mechanism 8 and the return spring 12 which change the relative position by utilizing the fact that the flow direction of the circulating flow changes according to the speed ratio, Without performing stator drive control such as outputting a drive command based on the detection of the speed ratio to the actuator that drives, while making it advantageous in terms of cost and maintenance,
The above effect can be achieved.

(Second Embodiment) FIG. 6 is a sectional view showing a coreless torque converter according to a second embodiment of the present invention.

In the second embodiment, a diagonally cut key groove is provided between the one-way clutch 6 and the movable stator 9 as a movable mechanism of the movable stator 9 whose relative position changes depending on the speed ratio. A key slide mechanism 13 in which a half-moon key or the like is inserted in the groove is provided.
A movable mechanism is constituted by 3 and the return spring 12. The rest of the configuration and operation are the same as in the first embodiment, so a description thereof will be omitted.

Effectively, in addition to the effects of (1) and (2), since the key slide mechanism 13 is provided between the movable stator 9 and the one-way clutch 6, only the movable stator 9 is axially moved. Therefore, it is possible to expect a more reliable clutch operation of the one-way clutch 6 and a smoother slad operation of the movable stator 9 according to the speed ratio.

Although the embodiments have been described above with reference to the drawings, the specific construction is not limited to the first and second embodiments.

For example, in both the first and second embodiments, an example of the movable stator supported by the movable mechanism that changes the relative position by utilizing the fact that the flow direction of the circulating flow changes according to the speed ratio is shown. The speed ratio may be calculated from the number of rotations and the turbine speed, and the movable stator may be driven by the actuator according to the speed ratio.

[0046]

According to the coreless torque converter of the present invention as set forth in claim 1, in the coreless torque converter having no core in the portion where the blades are gathered, the clearance with the pump impeller is provided on the low speed ratio region side. Keep
On the high speed ratio region side, a movable stator whose relative position changes according to the speed ratio is provided to maintain the clearance with the turbine runner, so the torque ratio is improved in the low speed ratio region and the capacity is improved in the high speed ratio region. It is possible to obtain the effect that both can be achieved.

In the coreless torque converter according to the second aspect of the present invention, the movable stator is supported by the movable mechanism that changes the relative position by utilizing the fact that the flow direction of the circulating flow changes according to the speed ratio. Therefore, it is possible to obtain the effect that the above effect can be achieved while being advantageous in terms of cost and maintenance.

[Brief description of drawings]

FIG. 1 is a sectional view showing a coreless torque converter according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a spline is cut on the stator shaft of the first embodiment of the present invention (FIG. 2a) and a positional relationship between the spline and the movable stator (FIG. 2b).

FIG. 3 is a diagram showing a state in which a circulating flow of the first embodiment of the present invention acts on a movable stator according to a speed ratio. FIG. 3a is a low speed ratio state, FIG. 3b is a medium speed ratio state, and FIG. The speed ratio state is shown.

FIG. 4 is a diagram showing a flow pattern in the coreless torque converter of the first embodiment of the present invention.

FIG. 5 is a characteristic diagram showing a performance test result of the coreless torque converter.

FIG. 6 is a sectional view showing a coreless torque converter of a second embodiment of the present invention.

FIG. 7 is a sectional view showing a conventional coreless torque converter.

FIG. 8 is a diagram showing a flow pattern in a conventional coreless torque converter.

[Explanation of symbols]

 1 Converter Cover 2 Pump Impeller 3 Transmission Input Shaft 4 Turbine Hub 5 Turbine Runner 6 One-way Clutch 7 Stator Shaft 8 Spline Slide Mechanism 9 Movable Stator 10, 11 Clearance 12 Return Spring

Claims (2)

[Claims] 1. A coreless torque converter having three elements, a pump impeller, a turbine runner, and a stator, and having no core at a portion where these blades are gathered, wherein the stator is formed to have a short axial dimension. In order to maintain the clearance with the pump impeller on the low speed ratio region side and the clearance with the turbine runner on the high speed ratio region side, the coreless is characterized by being a movable stator whose relative position changes according to the speed ratio. Torque converter. 2. The coreless torque converter according to claim 1, wherein the movable stator is supported by a movable mechanism that changes relative positions by utilizing the fact that the flow direction of the circulating flow changes according to the speed ratio. And a coreless torque converter.