JPH11118020A - Torque converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve transmitting efficiency as well as increasing a torque capacity coefficient, and provide a torque converter having a good fuel consumption at low cost. SOLUTION: This device is composed of three elements of a pump impeller 1, a turbine 2, and a stator 3. Power is transmitted to the pump impeller 1 through a fluid by the turbine 2. The stator 3 is positioned from an inner race fixed to a casing 14 through a one-way clutch 4. Especially, a turbine shell 6 or a turbine core 8 of the pump impeller 1 or the turbine 2 is formed in a convex shape by expanding toward a flow passage outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a torque converter used for an automobile or the like.

[0002]

2. Description of the Related Art As a conventional torque converter, for example, the one shown in FIG. 7 is known. In this torque converter, the so-called “flow path” through which the fluid flows includes an inlet of the pump 1a, an outlet of the pump 1a, an inlet of the turbine 2a, an outlet of the turbine 2a, an inlet of the stator 3a, an outlet of the stator 3a, and each element 1a, The flow passage areas at the inlet and the outlet of 2a and 3a are designed to be substantially constant, and the area is about 23% of the area of a circle having a diameter equal to the outer diameter of the torque converter called "nominal diameter". It is designed to be.

[0003] As described above, the torque converter is composed of the three elements of the pump 1a, the turbine 2a, and the stator 3a. The pump 1a rotates in synchronism with the rotation of the engine. Although not shown, it is connected to a gear transmission input shaft.

The torque is transmitted through a fluid filled therein, and the flow of the torque flows from the pump 1a to the stator 3a via the turbine 2a under normal operating conditions. Is performed.

The stator 3a is fixed to a casing 14 via a one-way clutch 4. The stator 3a is fixed at the time of starting, and amplifies the torque by the torque received by the stator 3a. After the coupling point, the stator 3a idles, and the torque converter becomes a fluid coupling.

As described above, the torque converter has a function of absorbing and amplifying the torque, and the absorbed torque balances the work performed by the fluid flowing through the internal pump 1a. The index of the torque that can be absorbed is called a torque capacity coefficient. If this torque capacity coefficient is smaller than the engine torque to be balanced, the engine will rotate at a high speed, and the fuel efficiency will be greatly deteriorated. Further, if the torque capacity coefficient is too large than the engine torque to be balanced, the load on the engine increases and the engine stops, so that the torque capacity coefficient needs to be optimized. In the drawings, reference numeral 5a denotes a pump shell, reference numeral 6a denotes a turbine shell, reference numeral 7a denotes a pump core, and reference numeral 8a denotes a turbine core.

[0007]

However, in such a conventional torque converter, since the flow path area ratio is constant at approximately 23% as described above, there is a limit in increasing the torque capacity coefficient. Since the torque capacity coefficient of the torque converter cannot be increased for an engine having a large engine torque, the use of a torque converter having a low torque capacity coefficient eventually results in a significant decrease in fuel efficiency, or In order to secure a torque capacity coefficient, the use of a motor having a larger "nominal diameter" causes an increase in weight, and also has a problem that fuel efficiency is significantly deteriorated or cost is increased. .

The present invention has been made in view of the above situation, and has as its object the same "nominal diameter" as before without lowering the transmission efficiency and increasing the "nominal diameter". By changing the shell or core shape while maintaining the “diameter”, the flow rate in the flow path is increased, the torque capacity coefficient is increased, and the secondary flow is reduced to cause separation in the flow path. Therefore, it is an object of the present invention to provide a torque converter capable of greatly improving the transmission efficiency of the torque converter by suppressing the above.

[0009]

In order to achieve the above-mentioned object, according to the present invention, as described in claim 1,
In a torque converter having three elements including an input-side pump impeller, a turbine that transmits power to the pump impeller via a fluid, and a stator fixed to a casing via a one-way clutch, a pump or turbine The shape of each shell or core is formed so as to bulge out so as to protrude toward the outside of the flow path.

Further, according to the invention described in claim 2, in the portion having the convex shape, the displacement amount gradually increases from the middle portion to the outlet with respect to the flow direction of the flow path of the turbine, It is characterized by having a shape with the maximum displacement at the outlet.

Further, in the invention described in claim 3, the amount of displacement of the portion having the convex shape gradually decreases from the inlet portion toward the intermediate portion with respect to the flow direction of the pump. , And has a shape that causes a maximum displacement at the entrance portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings.

FIGS. 1 to 4 show a first embodiment of the present invention. The torque converter in this embodiment is similar to the conventional torque converter structure shown in FIG.
As shown in (a), a pump impeller 1 on the input side, a turbine 2 for transmitting power to the pump impeller 1 via a fluid, and a one-way clutch fixed to a casing 14 and allowed to rotate only in one direction from an inner race. 4 and a stator 3 positioned via the reference numeral 4.

As shown in FIGS. 1B, 2 and 3, the turbine 2 has a shape in which the shell 6 is convex outward with respect to the flow path.

That is, as shown in FIG. 1B, the conventional structure has a shell-side surface indicated by a broken line, whereas in the case of the present embodiment, it has a shell-side surface indicated by a solid line. Therefore, in the case of the present embodiment, the side surface on the turbine shell 6 side is displaced by the distance indicated by reference numeral 13 with respect to the conventional structure.

In this embodiment, the turbine shell 6 side of the turbine 2 is illustrated, but in this embodiment, the pump core 7 side of the turbine core 8 and the pump 1
Is similarly configured. 1B, reference numeral 5 denotes a pump shell, reference numeral 9 denotes a pump blade pressure surface, reference numeral 10 denotes a pump blade negative pressure surface, reference numeral 11 denotes a turbine blade pressure surface, and reference numeral 12 denotes a turbine blade negative pressure surface. Are respectively shown.

Next, the operation of the torque converter having the above-described configuration will be described by taking as an example a case where the shape on the turbine shell 6 side is a shape that is convex with respect to the flow path.

Compared with the conventional torque converter having the structure shown in FIG. 3B, the torque converter according to the present embodiment has a flow rate corresponding to the amount of the bulge as shown in FIG. 3C. Increases, and the torque capacity coefficient increases accordingly.

FIG. 4 shows the latter half of the turbine (60% from the inlet).
Degree) of the secondary flow vector. Here, FIG.
It can be seen that the secondary flow is slightly reduced and the flow is improved as compared with the conventional structure shown in FIG. In particular, in the conventional structure, as shown in FIG. 4A, the low-energy fluid often accumulates at the rectangular corner C and induces separation from that portion, but in the structure of the present embodiment, the protrusion is convex. 4A, the secondary flow is less likely to accumulate at the corner D shown in FIG. 4A, and the flow is more resistant to separation. Thus, according to the structure of the present embodiment, it is possible to simultaneously improve the torque capacity coefficient and the transmission efficiency.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, the outlet of the turbine 2 which is particularly effective for improving the torque capacity coefficient is shown in FIG.
As shown in FIG. 5A, except that the flow path area is maximized, other configurations and operations are as shown in FIG.
This is the same as the first embodiment.

That is, the torque converter according to the present embodiment has the most narrowed shape at the outlet of the turbine 2 and the outlet of the stator 3.

By the way, increasing the flow path area at the outlet of the turbine 2 can increase the torque capacity coefficient, so that the sensitivity is extremely high.

Therefore, in the present embodiment, the displacement that becomes convex at the outlet of the turbine 2 is maximized, and the displacement that becomes gradually convex from the vicinity of the intermediate portion of the turbine 2 that enters the speed increasing process of the turbine 2 is increased. It is composed.

That is, in this embodiment, the dimension in the axial direction, which is the most important for flattening, is hardly affected.
It is important to obtain this effect. In FIG. 5A, reference numeral 11 denotes a turbine blade pressure surface, and reference numeral 12 denotes a turbine blade negative pressure surface. Reference numeral 13 represents a convex displacement as described above.

FIG. 6 shows a third embodiment of the present invention. In this embodiment, the inlet of the pump 1 which is particularly effective in improving the torque capacity coefficient is shown in FIG. 6 (b). Other than the shape having the maximum flow path area, other configurations and operations are the same as those of the torque converter according to the first embodiment as shown in FIG. The reference numerals used in the first embodiment are assigned, and the detailed description is omitted here.

By the way, if the area of the flow path at the inlet of the pump 1 is increased, the torque capacity coefficient can be increased, so that the sensitivity becomes extremely high.

In this embodiment, as in the case of the first embodiment, it is also important to obtain this effect without substantially affecting the axial dimension which is most important for flattening.

As described above, according to the torque converter according to each of the above embodiments, it is possible to simultaneously improve the torque capacity coefficient and the transmission efficiency by relatively low-cost means of changing only the shell or the core. it can.

Further, according to the torque converter according to each of the above embodiments, by making the shell side convex with respect to the turbine shell, it is possible to increase the strength against so-called falling, so that the turbine shell caused by the falling is Can elastically deform in the direction approaching the pump side, and can also solve the interference with the pump element.

[0030]

As described above, in the torque converter according to the present invention, since the shape of the shell or core of the pump or the turbine is formed so as to protrude outside the flow path with respect to the cross section of the flow path, The flow rate in the road increases,
Since the torque capacity coefficient can be increased and the secondary flow is reduced, the occurrence of separation in the flow path can be suppressed, and as a result, the transmission efficiency of torque can be greatly improved. Accordingly, the present invention can be applied to an engine having a large engine torque.

[Brief description of the drawings]

FIGS. 1A and 1B show a torque converter according to a first embodiment of the present invention, in which FIG. 1A is a longitudinal sectional view, and FIG. 1B is an AA view of FIG.

FIG. 2 is a perspective view showing a turbine shell shape of the torque converter.

3 (a) is a side view of a main part cut out of a flow path section, FIG. 3 (b) is a view corresponding to a portion B of FIG. 3 (a) in a conventional torque converter, and FIG. It is a figure corresponding to the B section of (a) in a torque converter.

FIG. 4 (a) shows a secondary flow vector in the latter half of the turbine (position about 60% from the inlet) in the conventional structure,
(B) is an explanatory view showing a secondary flow vector in the latter half of the turbine (position about 60% from the inlet) in the structure of the present embodiment.

FIGS. 5A and 5B show a torque converter according to a second embodiment of the present invention, in which FIG. 5A is a longitudinal sectional view, and FIG. 5B is an EE view of FIG.

FIGS. 6A and 6B show a torque converter according to a third embodiment of the present invention, wherein FIG. 6A is a longitudinal sectional view, and FIG. 6B is an FF view of FIG.

FIG. 7 is a longitudinal sectional view showing a conventional general three-element type torque converter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump 2 Turbine 3 Stator 4 One-way clutch 6 Turbine shell 8 Turbine core 13 Turbine shell side side displacement part 14 Casing

Claims (3)

[Claims] 1. A torque converter having three elements including an input-side pump impeller, a turbine that transmits power to the pump impeller via fluid, and a stator fixed to a casing via a one-way clutch. A torque converter, wherein each shell or core of the pump or the turbine is formed so as to protrude outwardly of the flow path. 2. A portion having a convex shape has a shape in which the amount of displacement gradually increases from an intermediate portion to an outlet with respect to a flow direction of the flow path of the turbine, and the shape has a maximum displacement at the outlet. The torque converter according to claim 1, wherein the torque converter has: 3. The displacement of the portion having the convex shape gradually decreases from the inlet to the middle in the flow direction of the pump, and the displacement becomes maximum at the inlet. The torque converter according to claim 1, wherein the torque converter has a shape.