JPH0783308A - Coreless torque converter - Google Patents

Abstract

PURPOSE:To increase the torque capacity and realize compactness in a coreless converter which does not possess a core at a portion where respective vanes are gathered, by providing a core ring at the outer periphery of a stator, setting its center line at a position shifted toward a turbine runner side. CONSTITUTION:A pump impeller 1 is integrally coupled to a converter cover 4 to be connected to the crankshaft or the like of an engine, and a turbine runner 2 is fitted to a turbine hub to be coupled to a transmission input shaft. Also, a stator 3 consisting of an inner ring 3a, a stator vane 3b and a core ring 3c is arranged at an inner diameter side position interposed between the pump impeller 1 and the turbine runner 2, and is fixed at a transmission case through a one-way clutch 5. In this instance, the increase of the torque capacity is realized by setting the center line of the core ring 3c provided at the outer periphery of the stator 3, at a position (C<1/2B) shifted toward the turbine runner 2 side from a stator vane center line.

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 disclosed in Japanese Utility Model Laid-Open No. 1-1028055 is known.

In the above-mentioned conventional sources, a core ring made of a linear or strip-shaped member is provided in the central portion of the outer circumference of the stator in order to rectify the flow of the working fluid so as not to be biased and to secure the strength of the stator blades. A coreless torque converter is shown.

[0004]

However, in the above-mentioned conventional coreless torque converter, since the set position of the core ring provided on the outer circumference of the stator is the center position of the outer circumference, the low speed ratio region with a large circulation flow rate is provided. In the case of the coreless type, the core ring acts as a baffle for the flow path that flows from the outer circumference of the stator impeller side to the pump impeller in the internal circulation flow, and the torque capacity becomes smaller than when there is no core ring. There was a problem that it could not make full use of the feature (reduction in diameter).

That is, as shown in FIG. 11, the coreless torque converter having no coring can increase the circulation flow rate by not having a core member for restricting the flow of fluid.
Compared to a torque converter having a core of the same diameter, it has a characteristic that the torque capacity can be increased and fuel consumption can be improved. However, as is clear from FIG. 11, the center of the circulating fluid is biased toward the turbine runner side,
This causes torque fluctuations and reduced efficiency.

Therefore, the core ring is provided to rectify the internal circulation flow to stabilize the output torque, improve the efficiency, and improve the rigidity of the stator. As shown in FIG. 12, the core ring has an outer periphery. When set to the central position, a large virtual core part is formed where the fluid flow will stay,
This virtual core portion narrows the flow passage cross-sectional area and reduces the total circulating flow rate, resulting in a reduction in torque capacity.

The present invention has been made in view of the above problems, and an object thereof is to maintain a torque ratio and efficiency in a coreless torque converter that does not have a core in a portion where each blade is assembled. It is to achieve compactness by increasing the torque capacity as it is.

[0008]

In order to achieve the above object, the coreless torque converter of the first invention has a pump impeller, a turbine runner, and a stator, and does not have a core at a portion where these blades are gathered. In the coreless torque converter, a core ring is provided on the outer circumference of the stator, and the center line of the core ring in the rotation axis direction is set at a position displaced from the center line of the stator blade in the rotation axis direction to the turbine runner side. To do.

To achieve the above object, in the coreless torque converter of the second invention, 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 each blade of these is assembled. In the above, the core ring is provided only in the stator outer peripheral facing portion of the turbine runner.

[0010]

In the coreless torque converter in which the stator has no core ring, the flow on the meridian plane is such that the center of the circulation vortex is biased toward the turbine runner side. When the coring is arranged in this flow, the centering of the circulation vortex moves toward the center of the torus where the blades are gathered by the coring restraining the flow.

With respect to the center movement of this circulating vortex, in the first invention, the center line of the core ring is set at a position displaced from the stator blade center line to the turbine runner side, and in the second invention,
By providing the core ring only on the stator outer peripheral facing portion of the turbine runner, the center of the moving circulation vortex and the installation position of the core ring are substantially aligned, and the virtual core formed around the core ring The part becomes very small, and the flow becomes a circulation flow with a streamline drawn around the coring.

Therefore, the torque ratio and efficiency are maintained at the same level as the coreless torque converter having the conventional core ring by the rectifying action by the core ring, and the core ring flows from the outer periphery of the stator on the impeller side to the pump impeller. A large circulating flow rate is ensured by not becoming a baffle plate that narrows the torque, and the torque capacity is improved compared to the conventional coreless torque converter having a core ring.

[0013]

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 a coreless torque converter of a first embodiment corresponding to the first aspect of the invention.

In FIG. 1, 1 is a pump impeller, 2 is a turbine runner, 3 is a stator, 4 is a converter cover, 5 is a one-way clutch, and 6 is a turbine hub.

The pump impeller 1 is connected to a crankshaft or the like of the engine, is integrally connected to a converter cover 4 to which the rotational driving force from the engine is input, and is rotationally driven by the engine. This pump impeller 1
It is configured to have a pump shell 1a and a pump blade 1b.

The turbine runner 2 is attached to a turbine hub 6 to which a transmission input shaft is connected. This turbine runner 2 has a turbine shell 2a.
And a turbine blade 2b.

The stator 3 is the pump impeller 1
It is arranged at an inner diameter side position sandwiched between the turbine runner 2 and the turbine runner 2, and is fixed to a transmission case (not shown) via a one-way clutch 5. The stator 3 includes an inner ring 3a, a stator blade 3b, and a core ring 3c.

The core ring 3c is provided on the outer periphery of the stator 3, as shown in FIG.
Is set at a position (C <1 / 2B) shifted from the stator blade center line to the turbine runner 2 side, and the coring width L is set to 50% or less of the blade width B on the outer circumference of the stator.

Next, the operation will be described.

[Circulating Flow Action in Low Speed Ratio Range] FIG. 3 shows the flow state of the meridional surface in the low speed ratio range of the coreless torque converter of the first embodiment.

In the case of a coreless torque converter in which the stator does not have a core ring, the flow on the meridional plane is such that the center of the circulating vortex is biased toward the turbine runner side.

When the core ring is arranged in this flow, the center of the circulation vortex moves toward the central portion of the torus where the blades are gathered by restricting the flow by the core ring.

With respect to the center movement of this circulating vortex, the core ring 3c of the first embodiment is provided on the outer periphery of the stator 3, and the Y center line in the direction of the rotation axis thereof is X in the direction of the rotation axis of the stator blade.
Since it is set at a position displaced from the center line to the turbine runner 2 side, the center of the moving circulation vortex and the installation position of the core ring substantially coincide with each other, and as shown in FIG. The virtual core portion formed around is extremely small, and the circulation flow is such that a streamline is drawn around the core ring 3c.

Therefore, the torque ratio and efficiency are maintained at the same level as the coreless torque converter having the conventional core ring by the rectifying action by the core ring 3c, and
Since the core ring 3c does not serve as a baffle plate that narrows the flow path that flows from the impeller-side outer periphery of the stator 3 to the pump impeller 1, a large circulation flow rate is ensured, and the torque capacity is improved as compared to a coreless torque converter having a conventional core ring. .

[Positioning of Core Ring] First, in order to confirm the above operation, the present inventor performed a characteristic experiment by changing the position of a core ring having the same width on the outer circumference of the stator.

As shown in FIG. 1, when the blade width of the outer circumference of the stator is B and the width from the end portion on the turbine tanna side to the center line of the core ring is C, this experimental object is closer to the turbine (C = 0. 15B, C = 0.2B, C = 0.4
B), the center of the stator (C = 0.5B), and the impeller side (C = 0.85B).

The results of the torque capacity characteristic (τ), the torque ratio characteristic (t) and the efficiency characteristic (η) in this experiment are shown in FIG.

FIG. 4 shows that the torque capacity is higher in the low speed ratio range as the core ring is closer to the turbine, and the torque ratio and efficiency are almost the same regardless of the installation position of the core ring. Has become.

In particular, FIG. 5 shows the torque capacity characteristics with respect to the core ring position (C / B). When the core ring is set closer to the turbine, the torque capacity is larger than that when the core ring is set closer to the center of the stator and closer to the impeller. It can be seen that the capacity can be significantly increased.

According to this experiment, when the core ring 3c is installed near the turbine, the core ring 3c acts as the center of the circulation vortex, and the core ring 3c obstructs the flow rate into the pump impeller 1. This proves that this is not the case.

Further, since the torque capacity can be adjusted by the installation position (C = 0.15B, C = 0.2B, C = 0.4B) of the core ring 3c having the same width, the torque capacity having different torque capacity is different for each vehicle. It is possible to easily manufacture a converter (torque converter series).

[Setting of Coring Width] Next, in order to confirm the performance change depending on the core ring width, the present inventor conducted a characteristic experiment by providing a core ring with a different width at the center position of the outer circumference of the stator.

As shown in FIG. 1, when the blade width of the outer circumference of the stator is B and the coring width is L, L / B = 0% (no coring), L / B = 3, as shown in FIG.
1%, L / B = 62%, and L / B = 100%.

The results of the torque capacity characteristic (τ), torque ratio characteristic (t) and efficiency characteristic (η) obtained by this experiment are shown in FIG.

In FIG. 6, it is shown that the larger the core ring width is, the higher the torque capacity is in the low speed ratio region, and the smaller the core ring width is, the larger the torque ratio is. It has almost the same characteristics except for.

In particular, when L / B = 50% is added and the torque capacity gradient characteristic with respect to the coring width (L / B) is shown in FIG. 7, the torque capacity gradient is close to zero until L / B = 50%. It was found that the change in the torque capacity was small in terms of the value, but when L / B = 50% was exceeded, the torque capacity gradient became high, and the torque capacity was found to be greatly reduced as the speed ratio increased. The capacity gradient is calculated by using the torque capacity τ0.6 and the stall torque capacity τs at a speed ratio of 0.6.
It is given by the formula of (τ 0.6 −τ s) /0.6.

Further, when L / B = 50% is added and the stall torque ratio characteristic with respect to the coring width (L / B) is shown in FIG. 8, the stall torque ratio is large up to L / B = 50%. It was found that the stall torque ratio decreased when / B = 50% was exceeded.

That is, if the core ring is installed on the entire blade of the stator, the stall torque capacity becomes excessive, the fuel consumption at the time of idling deteriorates, the stall torque ratio decreases, and the starting performance deteriorates, which is not preferable.

This is because when the core ring is installed on the entire blade of the stator, the inflow and outflow of the fluid to and from the stator are blocked by the core ring, and the fluid flows from the turbine runner to the pump impeller as a short circuit to circulate the fluid. The state becomes close to that of a coupling, the torque capacity becomes excessive due to an increase in circulation flow rate, and at the same time, the stall torque ratio decreases due to a large decrease in flow rate flowing through the stator.

Therefore, in order not to decrease the stall torque ratio and increase the torque capacity, the coring width is set to L / B = 60% or less (most preferably L / B).
= 50% or less).

Next, the effect will be described.

(1) In the coreless torque converter having no core in the portion where each blade is assembled, the stator 3
A core ring 3c is provided on the outer circumference of the core ring 3c, and the center line of the core ring 3c is set at a position displaced from the stator blade center line to the turbine runner 2 side. Can be achieved.

(2) Since the stator 3 is provided with the core ring 3c having the characteristic of increasing the torque capacity as it is moved closer to the turbine runner 2, the torque can be changed only by changing the installation type of the core ring 3c. It is possible to make a converter series, and it is possible to achieve cost reduction as compared to a torque converter series by changing the type of the pump impeller.

That is, the conventional torque converter generally changes the torque capacity by changing the outlet angle of the impeller, and in this case, it is necessary to change the model of the pump impeller including the change of the impeller blades. However, the cost will increase significantly.

(3) Since the width L of the core ring 3c is set to 50% or less of the blade width B on the outer circumference of the stator, the stall torque ratio is not lowered, and the stall torque capacity is not excessively increased, resulting in high starting performance. It is possible to secure the fuel consumption and improve the fuel efficiency at the time of idling.

(Second Embodiment) FIG. 9 is a sectional view showing a coreless torque converter according to a second embodiment of the present invention.

In the coreless torque converter of the second embodiment, the core ring 3c 'having an elliptic cross section having a flow path resistance as small as possible is integrated with the stator blade 3b as a core ring instead of the plate shape as in the first embodiment. It is provided.
Since the other configurations are the same as those in the first embodiment, the corresponding components are designated by the same reference numerals and the description thereof will be omitted.

Regarding the operation and effect, the points different from the first embodiment will be described.

First, the core ring 3c 'is connected to the stator blade 3b.
It can be manufactured integrally by casting or the like, which is advantageous in terms of cost.

Secondly, since the core ring 3c 'has an elliptical cross section having a small flow path resistance, the streamlines of the circulation flow are formed more orderly than in the first embodiment, and the transmission efficiency is improved.

The other functions and effects are the same as those in the first embodiment, and the description thereof will be omitted.

(Third Embodiment) FIG. 10 is a sectional view showing a coreless torque converter according to a third embodiment of the present invention.

In the coreless torque converter of the third embodiment, the core ring 3c ″ is provided only on the stator outer peripheral facing portion of the turbine runner 2. The other configurations are as follows.
Since this is the same as the first embodiment, the corresponding components are designated by the same reference numerals and the description thereof is omitted.

The function and effect are the same as those of the first embodiment except for the series of torque converters, and therefore the description thereof will be omitted.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the example in which the core ring is applied to the coreless torque converter without the lockup clutch has been shown, but it is needless to say that it can be applied to the coreless torque converter with the lockup clutch.

[0059]

According to the present invention as set forth in claim 1, in a coreless torque converter having no core in a portion where each blade is assembled, a core ring is provided on the outer periphery of the stator, and a center line of the core ring is provided. Is set at a position shifted from the stator blade center line to the turbine runner side, so that it is possible to achieve compactness by increasing the torque capacity while maintaining the torque ratio and efficiency.

According to the second aspect of the present invention, in the coreless torque converter having no core at the portion where the blades are gathered, the core ring is provided only at the stator outer peripheral facing portion of the turbine runner. Therefore, it is possible to obtain a high level of compatibility between ensuring the starting performance in the low speed ratio range and improving the fuel efficiency in the high speed ratio range.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a stator of the coreless torque converter of the first embodiment.

FIG. 3 is a diagram showing a flow state of a fluid circulating inside a low speed ratio region of the coreless torque converter of the first embodiment.

FIG. 4 is a torque converter characteristic comparison diagram when the installation position of the core ring on the outer circumference of the stator is changed.

FIG. 5 is a torque capacity characteristic diagram with respect to a coring position.

FIG. 6 is a torque converter characteristic comparison diagram when a core ring having a different width is provided at a central position on the outer circumference of the stator.

FIG. 7 is a capacity gradient characteristic diagram with respect to a coring width.

FIG. 8 is a characteristic diagram of a stall torque ratio with respect to a coring width.

FIG. 9 is a sectional view showing a coreless torque converter of a second embodiment of the present invention.

FIG. 10 is a sectional view showing a coreless torque converter of a third embodiment of the present invention.

FIG. 11 is a diagram showing a flow state of a fluid circulating inside a coreless torque converter without a core ring.

FIG. 12 is a diagram showing a flow state of a fluid circulating inside a coreless torque converter having a core ring at a central position on the outer circumference of a stator.

[Explanation of symbols]

 1 Pump Impeller 2 Turbine Runner 3 Stator 3c Coring

Claims (2)

[Claims] 1. A coreless torque converter having a pump impeller, a turbine runner, and a stator, and having no core in a portion where these blades are gathered, wherein a core ring is provided on an outer periphery of the stator, A coreless torque converter characterized in that a center line in the rotation axis direction is set to a position displaced from a center line in the rotation axis direction of the stator blade toward the turbine runner side. 2. A coreless torque converter that has a pump impeller, a turbine runner, and a stator, and does not have a core in a portion where these blades are gathered, wherein a core ring is provided only in a stator outer peripheral facing portion of the turbine runner. A coreless torque converter that is characterized by