JP2004052936A - Fluid impeller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid impeller maintaining sufficient bonding strength of a blade and core by brazing and fixing the blade and core having a projection of the blade fitted in a slit without non-connect part. <P>SOLUTION: A pump 20 which is the fluid impeller is provided with a shell 2, a plurality of blades 3 radially arranged on the shell 2, a core 4 mounted on the blade, and a retainer 5 pressing the blade downward. The projection 11 of the blade 3 is fitted to the slit 10 of the core 4. The shell 2 and each blade 3, each blade 3 and the core 4 are fixed by brazing. A recess part 12 is provided on the projection 11 of the blade 3 and a wire ring shape brazing material 13 is retained in the recess part 12 in order to spread out molten brazing material to whole contact part of the blade 3 and the core 4 by capillary action through the slit 10 in all blades 3. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluid impeller used in a torque converter or the like, and more particularly to a fluid impeller having an improved brazing structure for brazing blades to a shell.
[0002]
[Prior art]
BACKGROUND ART Conventionally, as a fluid impeller such as a pump impeller or a turbine runner of a torque converter, for example, one disclosed in Japanese Patent Application Laid-Open No. 58-97448 is known.
[0003]
This is a fluid impeller using single type blades separated one by one. Conventionally, in this type of single blade type fluid impeller, the protrusion of the blade is fitted into the slit of the core and the slit is inserted into the slit. The blade and the core are welded with the brazing material from the fitted projections to prepare a core / blade assembly in advance, and then placed on a shell in a state where it is laid horizontally, and the blade is attached to the shell. After positioning the outer end and the inner end, a brazing material in the form of a wire was placed at a position near the outer end of the blade, and the blade and the shell were brazed and fixed by passing through a furnace in a predetermined atmosphere. The positioning of the outer end of the blade with respect to the shell is performed by, for example, fitting of unevenness, and the positioning of the inner end of the blade is performed by fitting of unevenness and / or holding by a retainer.
[0004]
However, in the above-mentioned single blade type, in order to produce a core / blade assembly, it is necessary to weld with a brazing material aiming at a projection of the blade previously fitted to the core, which requires labor and precision in the assembly work. There was a problem.
[0005]
Therefore, the present applicant recently proposed a fluid impeller disclosed in JP-A-2001-141028. This uses a connection-type blade whose outer edges are connected to each other by an annular connection portion. In this blade connection type, since it is not necessary to assemble the core and the blade in advance, the outer and inner ends of the blade are directly positioned on the shell in a horizontal state, and the blade is directly placed on the shell. Then, in the same manner as described above, the protrusion is fitted to the slit, and the core is placed on the blade.After that, the wiring brazing material is placed at the position of the protrusion of the blade and the position near the outer end, and the inside of the furnace is cooled. The blade and the core, and the blade and the shell are brazed and fixed by passing through.
[0006]
[Problems to be solved by the invention]
In this blade connection type, it is not necessary to perform welding work with a brazing material in advance aiming at the protrusion of the blade fitted to the core, but it is difficult to position the brazing material so as to contact all the protrusions. As a result, the melted brazing material accumulates in areas other than the slits on the core, and the brazing material cannot be spread from the slits to the entire contact portion between the blade and the core by utilizing the capillary phenomenon. There is a problem in that a non-joined portion remains between the core and a blade having insufficient bonding strength with the core.
[0007]
Such a problem is that a single type blade is placed directly on a shell without separating a single type blade into a core / blade assembly, and the blade and the shell, the blade and the The same occurs when brazing the upper core.
[0008]
Therefore, an object of the present invention is to provide a fluid impeller having a blade and a core having a sufficient bonding strength by brazing and fixing the blade and the core having the protrusion fitted into the slit without generating a non-bonded portion. To provide.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is to position a number of blades radially arranged with respect to a shell, fit a protrusion on an inner edge of the blade into a slit of a core, and set the blade in a state of being placed horizontally. In a fluid impeller in which the inner edge of the blade, the core, and the outer edge of the blade and the shell are brazed by placing and heating a wiring-like brazing material at the position of the protrusion and the position near the outer end, the protrusion of the blade A recess is provided, and the brazing material at the position of the protrusion is held in the recess.
[0010]
According to the invention, the recess has a depth to hold the brazing material. Preferably, the recess is formed as a groove having a substantially parallel straight line portion. A retainer may be provided for positioning an inner end of the blade with respect to the shell. Further, the blade may be a connection type blade in which outer edges of the blades are connected by an annular connection portion, and preferably, a gap is provided without contacting the connection portion with the shell.
[0011]
In the present invention, the wiring brazing material for joining the blade and the core is held in the recess of the protrusion of the blade fitted to the slit of the core, so that in each blade, the melted brazing material passes through the protrusion and enters the slit. By penetrating into the gap between the contact portion between the inner edge of the blade and the core due to the capillary action, the blade and the core are satisfactorily fixed to all the blades without any non-joined portions. Therefore, the fluid wheel can have sufficient bonding strength between the blade and the core.
[0012]
When the concave portion of the projection is formed as a hole having a parallel linear portion, the brazing material inserted into the concave portion can be held in a press-contact state by the linear portion from both sides of the cross section, so that the brazing material can be more effectively removed from the concave portion. Can be prevented. As the blades, besides a single type separated from each other, a connection type in which the outer edges of the blades are connected by an annular connection portion can be used. In this case, the connection portion of the blade is brazed to the shell. Even so, there is almost no effect on the bonding strength of the blade itself to the shell. Therefore, if a gap is provided without contact between the connecting portion and the shell, the connecting portion can be prevented from being brazed to the shell, and brazing material can be saved correspondingly.
[0013]
When a retainer for positioning the inner end of the blade with respect to the shell is provided, a gap is formed between the retainer and the inner end of the blade in the circumferential direction of the retainer. Even if the brazing material is interrupted in the middle of the contact part, the brazing material penetrates into the retainer circumferential gap at the point where the melted brazing material propagates to the inner end of the blade, and the brazing material It can penetrate into the gap between the contact portion between the outer edge and the shell. Therefore, with all the blades, it is possible to more reliably obtain good brazing without a non-joining portion with the shell.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0015]
FIG. 1 is a plan view showing an embodiment of the fluid impeller of the present invention.
[0016]
As shown in FIG. 1, in the present embodiment, the fluid impeller is formed as a pump impeller (hereinafter simply referred to as a pump) of a torque converter. The pump 20 includes a shell 2, a large number of 15 to 30 blades, for example, 23 blades 3 in this example, radially arranged with respect to the shell 2, and a core 4 mounted on the blade 3. A retainer 5 for holding the lower end of the blade 3 is provided, and the space between the shell 2 and each blade 3 and the space between each blade 3 and the core 4 are fixed by brazing. The blade 3 has a loosely twisted surface shape.
[0017]
As shown in FIG. 2, tongue pieces 6, 7 protruding outward are provided integrally with the outer end 3 c and the inner end 3 d of each blade 3, respectively. Concave portions 8 and 9 corresponding to the tongue pieces 6 and 7 of the blade 3 are provided at the inner surface position near the portion. In addition, a projection 11 is provided at a substantially central portion on the inner edge 3a between the outer and inner straight portions 3e and 3f following the outer end 3c and the inner end 3d of each blade 3, and the core 4 has A corresponding slit 10 is provided.
[0018]
A major feature of the present invention is that a recess 12 is provided in the protrusion 11 of the blade 3 and the blade 3 and the core 4 are brazed using the brazing material held in the recess 12.
[0019]
The present invention will be further described according to the method of assembling the pump 20. First, as shown in FIG. 3, the shell 2 is set on a set jig 16 in a state of being placed horizontally, and the blades 3 are radially placed on the shell 2. The outer end 3c of each blade 3 is positioned with respect to the shell 2 by inserting the tongue piece 6 at the outer end of each blade 3 into the recess 8 of the shell 2. The tongue 7 at the inner end of each blade 3 is inserted into the recess 9 of the shell, and the tongue 7 is pressed from above by the retainer 5 to position the inner end 3 d of each blade 3 with respect to the shell 2. The retainer 5 is fixed to the shell 2 by spot welding 17 or the like.
[0020]
Next, the core 4 is placed on the inner edge 3 a of the blade 3 arranged on the shell 2, the protrusion 11 of each blade 3 is fitted into the slit 10 of the core 4, and the shell 2 is placed on the set jig 16. A subassembly 15 of the blade 3 and the core 4 is obtained. Then, a wire-shaped brazing material 13 is inserted into the recess 12 of the protrusion 11 of the blade 3 in the subassembly 15 and held, and the wire-shaped brazing material is placed near the outer end 3c of the linear portion 3e outside the blade 3. Place 14.
[0021]
As shown in FIG. 4, the recess 12 of the projection 11 has a depth that holds the brazing material 13, that is, a depth that accommodates substantially the entire cross section of the brazing material 13. The recess 12 is formed in a groove having substantially parallel straight portions 12a. By doing so, the brazing material 13 inserted into the recess 12 can be held in a press-contact state by the linear portions 12a from both sides of the cross section, so that the brazing material 13 can be prevented from coming off from the recess 12 more effectively. The cross-sectional area of the brazing material 13 is adjusted by changing the cross-sectional shape of the brazing material 13 to a circle, an ellipse, or the like in accordance with the necessary amount of the brazing material 13. It is specifically determined according to the size of the cross section.
[0022]
As described above, the brazing material 13 is held in the concave portion 12 of the projection 11 of the blade 3 of the subassembly 15 on the setting jig 16, and the brazing material 14 is placed on the straight portion 3 e outside the blade 3. The subassembly 15 together with the jig 16 is placed in a furnace in an inert atmosphere such as nitrogen gas and heated by passing through the furnace. As a result, the brazing material 13 is melted and the blade 3 and the core 4 are brazed, and the brazing material 14 is melted and the blade 3 and the shell 2 are brazed.
[0023]
Since the brazing material 13 for joining the blade 3 and the core 4 is held in the concave portion 12 provided in the projection 11 of the blade 3 fitted in the slit 10 of the core 4, the brazing material melted by each blade 3 After passing through the projection 11 and entering the slit 10, it penetrates into the gap between the contact portion between the inner edge 3 a of the blade 3 and the core 4 by capillary action and spreads over the whole. Therefore, in all the blades 3, the blades 3 and the core 4 are brazed and fixed without generating a non-joined portion.
[0024]
On the other hand, the brazing of the blade 3 and the shell 2 is performed by melting the brazing material 14 of the straight portion 3e of the blade 3, and the melted brazing material enters the gap between the outer end 3c of the blade 3 and the shell 2, and is caused by capillary action. The blade 3 and the shell 2 are brazed by penetrating into the gap at the contact portion between the outer edge 3a of the blade 3 and the shell 2 and spreading all over.
[0025]
The brazing of the blade 3 and the shell 2 is normally performed well without any problem. However, depending on the blade 3, the melted brazing material may be interrupted in the middle of the gap between the outer edge 3a of the blade 3 and the shell 2. .
[0026]
On the other hand, as described above, if the retainer 5 is used for positioning the inner end 3d of the blade 3, a gap is generated between the retainer 5 and the inner end 3d of the blade 3 in the circumferential direction of the retainer 5. At the point where the melted brazing material propagates to the inner end 3d of the blade 3, the brazing material penetrates into the circumferential gap of the retainer 5 and the brazing material is removed therefrom at the contact portion between the outer edge 3b of the blade 3b and the shell 2 interrupted. Can be permeated into the gap. Therefore, good brazing without any non-joining portions between the blades 3 and the shell 2 can be more reliably obtained with all the blades 3.
[0027]
According to the present embodiment, as described above, with all the blades, the melted brazing material is spread over the entire contact portion between the blade and the core, and the blade and the core are brazed without generating a non-joined portion. The pump can be fixed, and the blade and the core can have sufficient bonding strength.
[0028]
FIG. 5 shows an example of a torque converter to which the pump of the present embodiment is assembled.
[0029]
The torque converter (fluid power transmission) 30 includes the pump 20, a turbine runner (turbine for short) 33, and a stator 47. The pump 20 is welded to the hub 31 a at the inner edge of the shell 2, and the turbine 33 is welded to the hub 33 a at the inner edge of the shell 34, and are arranged to face each other. The hub 33a is configured to co-rotate with a driven shaft S that is an output shaft. The stator 47 is connected to a fixed shaft via a one-way clutch 47a and a hub 47b.
[0030]
The turbine 33 has a configuration substantially similar to that of the pump 20, and is formed by integrally assembling the shell 34, the blades 35 radially arranged on the shell 34, and the core 35a thereon. An outer peripheral end 34a of the shell 34 is arranged to face the pump 20 side, and an inner surface of the end 34a is formed on a surface substantially coincident with an imaginary line 36 indicating an outer peripheral surface of a flow flowing from the pump 20. The outer diameter of the end portion 34a is set to a size where a slight gap 37 is formed between the end portion 34a and the inner surface of the shell 2 on the pump 20 side.
[0031]
The front cover 38 has a hub 38a loosely fitted on the driven shaft S, and an outer peripheral portion connected to the shell 2 on the pump 20 side by a welded portion 39 to form a container of the torque converter 30. The nut 40 and the ring gear 41 for connecting the drive rate are welded.
[0032]
The clutch plate 42 includes a hub 42a, a friction plate 42b, and several spring holding portions 43. A coil spring 44 is inserted into the spring holding portion 43, and both ends of the coil spring 44 are held by retainers 45. The shell 34 of the turbine 33 is provided with a pair of projecting pieces 46 for contacting both ends of the coil spring 44 for each spring, and transmits the rotation from the projecting piece 46 to the clutch plate 42 via the coil spring 44. Therefore, when the clutch plate 42 moves rightward due to the pressure difference and the friction plate 42b contacts the front cover 38, the input applied to the front cover 38 is transmitted to the shell 34 of the turbine 33 via the coil spring 44 and the projecting piece 46, and It is transmitted from 33a to the driven shaft (output shaft) S.
[0033]
FIG. 6 shows another embodiment of the fluid impeller of the present invention. The present embodiment is characterized in that the connection type blade proposed in Japanese Patent Application Laid-Open No. 2001-141028 is used as the blade 3 of the pump 20.
[0034]
This connection type blade 3 is formed by punching a band-shaped metal plate so that the blades 3 are connected to each other at the outer end 3c by a connection portion 3g via a branch portion 3h, and the blade 3 is twisted. It is raised from the plane including the connecting portion 3g, the branch portion 3h connected to the connecting portion 3g is bent to change the direction of the connecting portion, and the connecting portion 3g is made annular to connect the ends. A gap 18 is provided between the connecting portion 3g and the inner surface of the outer peripheral portion of the shell 2 without making contact.
[0035]
Other configurations of the pump 20 of the present embodiment are basically the same as those of the embodiment shown with reference to FIGS. 1 to 4, and position the blade 3 with respect to the shell 2, and The subassembly fitted to the slit 10 of the core 4 is passed through a furnace in a horizontal state, so that the wiring brazing material held in the recess 12 of the protrusion 11 of the blade 3 and the straight portion 3 e of the blade 3 are formed. The blade 3 and the core 4 and the blade 3 and the shell 2 are brazed with a wiring brazing material placed near the outer end.
[0036]
In this connection type, since the blades 3 are connected by the connection portion 3g, there is a general advantage that the positioning of the blade 3 with respect to the shell 2 is easy and the strength of the blade is enhanced by the connection portion. Further, since the gap 18 is provided between the connecting portion 3g and the outer peripheral portion of the shell 2, the insertability of the blade 3 connected by the connecting portion 3g to the shell 2 is good, and the blade 3 can be inserted in the axial direction and the radial direction. Is allowed, and the strength of the blade can be further improved.
[0037]
Further, even if the connecting portion 3g of the blade 3 is brazed to the shell 2, it hardly affects the joining strength of the blade 3 itself to the shell 2, so that a gap is provided without bringing the connecting portion 3g into contact with the shell 2. By doing so, the connecting portion 3g can be prevented from being brazed to the shell 2, and the brazing material can be saved correspondingly.
[0038]
In each of the above embodiments, the description has been given of the pump of the torque converter. However, the present invention can be applied to a turbine of the torque converter, and further can be widely applied to a fluid wheel of a fluid transmission device.
[0039]
【The invention's effect】
As is clear from the above description, according to the present invention, the brazing material that has melted is spread over the entire contact portion between the blade and the core in which the protrusion of the blade is fitted into the slit, and the blade and the core are separated from each other. By brazing and fixing without forming a joining portion, the fluid wheel can have sufficient joining strength between the blade and the core.
[Brief description of the drawings]
FIG. 1 is a front view showing a pump according to an embodiment of a fluid impeller of the present invention.
FIG. 2 is a sectional view showing a method of assembling the pump of FIG. 1;
FIG. 3 is a sectional view showing a continuation of the assembling method of FIG. 2;
FIG. 4 is a plan view showing that a protrusion for holding a brazing material is provided on a protrusion of a blade which is a component of the pump of FIG. 1;
FIG. 5 is a sectional view showing an example of a torque converter incorporating the pump of FIG. 1;
FIG. 6 is a sectional view showing a pump according to another embodiment of the present invention.
[Explanation of symbols]
2 Shell 3 Blade 3a Inner edge 3b Outer edge 4 Core 5 Retainer 10 Slit 11 Projection 12 Recess 13, 14 Wiring-like brazing material 15 Sub-assembly 18 Gap 20 Pump

Claims (5)

A number of blades arranged radially with respect to the shell are positioned, the protrusions on the inner edge of the blades are fitted into the slits of the core, and the position of the protrusions on the blade and the position near the outer end are set in a state where the blades are placed horizontally. In the fluid impeller where the inner edge of the blade and the core and the outer edge of the blade and the shell are brazed by placing a wiring-shaped brazing material on the
A fluid impeller, wherein a recess is provided in the protrusion of the blade, and the brazing material at the position of the protrusion is held in the recess. The fluid impeller according to claim 1, wherein the recess has a depth for holding a brazing material. 3. The fluid impeller according to claim 1, wherein the recess is formed as a groove having a substantially parallel linear portion. The fluid impeller according to any one of claims 1 to 3, further comprising a retainer for positioning an inner end of the blade with respect to the shell. The blade is formed of a connection type blade in which outer edges of the blades are connected by an annular connection portion, and a gap is provided without contacting the connection portion and the shell. 5. The fluid impeller according to any one of the above items 4.

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