JP4487404B2 - Torque converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a torque converter used in a drive system such as an automatic transmission, and more particularly to a shape of a stator blade for changing a capacity coefficient of the torque converter.
[0002]
[Prior art]
As a conventional technique, pages 75 to 78 of the Automotive Engineering Society Pre-Announcement 921 1992-5 show that the stator blades are designed to suppress the separation of the fluid on the back surface (suction surface) of the stator blade and reduce the drag. By improving the shape, the ratio of the turbine rotation speed to the pump rotation speed (hereinafter referred to as speed ratio) is approximately 0.3 to 0.6 while maintaining the torque ratio and efficiency. A technique for improving the capacity coefficient in the high speed ratio range of 0.6 to 0.9 is disclosed.
[0003]
[Problems to be solved by the invention]
However, the above prior art relates to a design method of the stator blade shape for suppressing the separation of the back surface of the stator blade. In this design method, the shape of the entire stator blade is uniquely determined. No further improvement in capacity factor can be expected.
[0004]
Therefore, in order to solve the above problems, it is a technical object of the present invention to provide a torque converter capable of further improving the capacity coefficient in a high speed ratio region.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is a torque converter including a pump having pump blades, a turbine having turbine blades, and a stator having stator blades, the stator blades facing the turbine and flowing from the turbine. An inlet portion that is an inlet for fluid, an outlet portion that is an outlet side of fluid that flows from the turbine facing the pump, a pressure surface that is formed facing the turbine side between the inlet portion and the outlet portion, and an inlet port The camber line connecting the intermediate portion between the pressure surface and the suction surface from the inlet portion to the outlet portion is provided on the outlet portion side. It was made to be bent to the suction surface side in the vicinity.
[0006]
According to the first aspect, since the stator blade is formed so that the camber line in the vicinity of the outlet portion bends toward the suction surface, the cross-sectional area of the flow passage in the vicinity of the outlet portion in the high speed ratio region is enlarged, and the torque ratio and efficiency are increased. It is possible to improve only the capacity coefficient in the high speed ratio region without changing. Thereby, vehicle power performance and fuel consumption performance are improved. Note that the actual channel cross-sectional area in the low speed ratio region has a large separation at the inlet and is determined by the inlet, so that the performance change such as the capacity coefficient in the low speed ratio is small.
[0007]
Here, in general, the shape of the stator blade is designed so that the camber line is not a straight line but a smooth curve. In the present invention, the camber line is bent at an angle with respect to the smooth curve. It is a state of being.
[0008]
Embodiment
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a main longitudinal sectional view of the torque converter in the present embodiment.
[0009]
The configuration will be described. FIG. 1 shows a torque converter 10 used for an automobile together with an automatic transmission (not shown). The torque converter 10 includes a plurality of pump blades 11a and is connected to an output shaft of an engine (not shown). The turbine 12 having a plurality of turbine blades 12a and connected to the input shaft of the automatic transmission is disposed between the pump 11 and the turbine 12 and rectifies the fluid flowing from the pump 11 side to the turbine 12 side. The stator 13 is provided with a plurality of stator blades 15, a lock-up clutch 14, and the like. The fluid flowing from the pump 11 toward the turbine 12 flows into the stator 13 as shown by the arrow direction in FIG.
[0010]
FIG. 2 is a front view of the stator 13 of the present embodiment as viewed from the turbine 12 side. The inner peripheral portion of the stator 13 is connected to the stator shaft via a one-way clutch, and is configured to be able to rotate only in the same rotational direction as the pump 11 and the turbine 12.
[0011]
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 of the stator blade 15 that is optimal at a high speed ratio. The stator blade 15 faces the pump 11 side and has an inlet portion 15a that is an inlet to the stator blade 15 of fluid pressure flowing from the pump 11 side, an outlet portion 15b that faces the turbine and flows from the pump, and a pump. A pressure surface 15c that receives fluid pressure from the 11 side to the turbine 12 side, and a suction surface 15d that is formed on the surface opposite to the pressure surface 15c, and an intermediate portion between the pressure surface 15c and the suction surface 15d. Is formed so as to be bent toward the suction surface 15d side in the vicinity of the outlet portion 15b side. In addition, the dotted line shown in the vicinity of the outlet portion 15b in FIG. 3 shows a stator blade having a general shape that has been conventionally used in order to clarify the characteristics of the stator blade 15 of the present embodiment.
[0012]
In the present embodiment, a one-way clutch is disposed between the cover of the torque converter 10 and the stator 13, and the speed ratio ranges from a low speed ratio range (0 or more and less than 0.3) to a medium speed ratio range (0 .3 or more and less than 0.6), the pressure surface 15c of the stator blade 15 recirculates fluid in the direction in which the pressure of the fluid is received, but after the speed ratio reaches the high speed ratio range (0.6 or more), the cup When larger than the ring region (0.9), the direction of the fluid returning from the pump 11 side to the turbine 12 side changes, and the fluid returning to the turbine 12 side from the pump 11 side on the suction surface 15d side of the stator blade 15 changes. Be under pressure. Therefore, the capacity coefficient cannot be adjusted in the coupling region where the speed ratio is greater than 0.9, and the stator 13 rotates with the suction surface 15d receiving fluid pressure by the one-way clutch. By rotating the stator 13, the fluid recirculating in the torque converter 10 is almost unaffected by the shape of the stator blade 15 in the region where the speed ratio is 0.9 or more, and moves from the pump 11 side to the turbine 12 side. The fluid recirculates. In the region where the speed ratio is smaller than 0.9, the stator 13 does not rotate, and restricts the flow of fluid from the turbine 12 to the pump 11.
[0013]
In other words, the stator 13 is configured so as not to rotate in the low speed ratio range and the medium speed ratio range by the one-way clutch, and to rotate in the high speed ratio range where the torque converter 10 is in the coupling state.
[0014]
Next, the operation of the torque converter 10 when the speed ratio between the turbine 12 and the pump 11 is in a high speed ratio range (0.6 or more and less than 0.9) will be described.
[0015]
In the high speed ratio region, the direction of the fluid returning from the turbine 12 side to the pump 11 side is an arrow direction in FIG. The high speed ratio region is a region aiming at overtaking acceleration of the vehicle, quietness during normal driving (reduction in engine speed), and the like, and the camber line near the exit portion 15b is bent toward the suction surface 15d. By forming the stator blade 15 as described above, the flow path cross-sectional area in the vicinity of the outlet portion 15b is enlarged, and only the capacity coefficient in the high speed ratio region is improved without changing the torque ratio or the efficiency. As a result, vehicle power performance such as overtaking acceleration and quietness and fuel efficiency are improved.
[0016]
FIG. 4 shows a performance comparison diagram comparing the capacity coefficient c, torque ratio t, and efficiency n between the stator blade 15 shown in FIG. 3 and the conventional stator blade (the camber line is not bent). In FIG. 4, the performance of the stator blade 15 is indicated by a solid line, and the conventional stator blade is indicated by a dotted line. As can be seen from FIG. 4, the torque ratio t and the efficiency n are not significantly different, but the capacity coefficient c in the high speed ratio region where the speed ratio is 0.6 to 0.9 is higher than that of the conventional stator blade. It can be seen that there is a significant improvement. This is because the channel cross-sectional area through which the fluid flows in the vicinity of the outlet portion 15b has increased.
[0017]
Note that the actual flow cross-sectional area in the low speed ratio region is greatly affected by separation at the inlet portion 15a, and the capacity coefficient, torque ratio, and efficiency in the low speed ratio region are determined by the shape of the inlet portion 15a. Therefore, the capacity coefficient, the torque ratio, and the efficiency in the low speed ratio region are small in change only by the shape change of the stator blade 15 in the vicinity of the outlet portion 15b as shown in the present invention.
[0018]
The embodiment of the present invention has been described above. However, the present invention is not intended to be limited to the above-described embodiment, and any configuration is possible as long as it is a stator blade according to the gist of the present invention. Also good.
[0019]
【The invention's effect】
According to the present invention, the stator blade is formed so that the camber line in the vicinity of the outlet portion bends to the suction surface side, so that the cross-sectional area of the flow passage in the vicinity of the outlet portion in the high speed ratio region is enlarged, and the torque ratio and efficiency are increased. Only the capacity coefficient in the high speed ratio region can be improved without being changed. Therefore, vehicle power performance and fuel consumption performance are improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a torque converter in the present embodiment.
FIG. 2 is a plan view of a stator in the present embodiment.
FIG. 3 is a cross-sectional view taken along line AA of FIG. 2 of a stator blade that is optimal for a high speed ratio region.
4 is a performance comparison diagram of the stator blade of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Torque converter 11 ... Pump 11a ... Pump blade 12 ... Turbine 12a ... Turbine blade 13 ... Stator 14 ... Lock-up clutch 15 ... Stator blade 15a ... Inlet portion 15b ... Outlet portion 15c ... Pressure surface 15d ... Suction surface 16 ... Camber line

Claims (1)

A torque converter comprising a pump having pump blades, a turbine having turbine blades and a stator having stator blades,
The stator blade has an inlet portion that faces the turbine and is an inlet of fluid flowing from the turbine, an outlet portion that faces the pump and is an outlet side of the fluid that flows from the turbine, the inlet portion and the outlet portion And a pressure surface formed facing the turbine side, and a suction surface formed facing the pump side between the inlet portion and the outlet portion,
A torque converter characterized in that a camber line connecting an intermediate portion between the pressure surface and the suction surface from the inlet portion to the outlet portion is formed to be bent toward the suction surface side in the vicinity of the outlet portion side. .

Images