JP2010078107A - Fluid coupling equipped with baffle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid coupling to improve fuel consumption when idling. <P>SOLUTION: A baffle 8 is attached to the pump hub 9 of a pump impeller 1, and has a plurality of slit holes 10 bored through the periphery of the baffle 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid coupling for the purpose of suppressing a reduction in fuel consumption during idling operation and improving transmission torque during normal operation.

  The fluid coupling has a pump impeller and a turbine runner arranged to face each other. The pump impeller is provided on the inner peripheral side of the impeller shell, a plurality of blades fixed to the impeller shell, and a plurality of blades fixed to the impeller shell. Core. The turbine runner includes an annular turbine shell, a plurality of blades fixed to the turbine shell, and a core provided on the inner peripheral side of the turbine shell. The pump impeller and the turbine runner are supported relative to each other via bearings.

  In the fluid coupling thus configured, the pump impeller is connected to the crankshaft which is a member on the engine side through the front cover, the turbine runner is attached to the turbine hub, and the output shaft fitted to the turbine hub is the transmission shaft. It is connected to. Therefore, the rotation of the pump impeller that receives power from the engine rotates the turbine runner via the working fluid filled in the outer shell, and the power is transmitted from the turbine runner to the transmission.

  By the way, in a general fluid coupling, the input capacity coefficient is high in the low speed ratio region, and the input capacity coefficient is decreased as it goes to the high speed ratio region. Therefore, when the vehicle is stopped by stepping on the brake and the engine is idling, the engine side performs control to keep the engine speed constant against the braking force, so that wasted fuel is supplied. Therefore, it is not preferable for improving fuel consumption.

  Therefore, attempts have been made in the past to reduce the input capacity coefficient in the low speed ratio region by providing a baffle plate in the fluid coupling and obstructing part of the flow of the working fluid. FIG. 8 shows a part of a conventional fluid coupling. In FIG. 8, (a) represents a pump impeller, (b) represents a turbine runner, (c) represents a baffle plate, and (d) represents a lock-up damper device. ing.

  The outer shell is filled with the working fluid, and the turbine impeller (b) rotates in the same direction as the pump impeller (b) rotates with the movement from the engine, and the working fluid discharged from the turbine runner (b) Is returned to the pump impeller (I). Then, when the rotational speed reaches a predetermined region, the piston (e) is activated and engaged with the front cover (f). A lock-up damper device (d) is provided to alleviate the impact torque at the time of engagement.

  Thus, the basic structure and basic operation as a fluid coupling are common to the torque converter. However, a baffle plate (c) is interposed between the pump impeller (a) and the turbine runner (b) in the fluid coupling shown in FIG. The baffle plate (c) functions to obstruct the flow of the working fluid that exits from the turbine runner (b) and enters the pump impeller (b). By interfering with the flow of the working fluid, the fuel efficiency during idling can be improved.

However, even during normal operation, especially during high input rotation, the baffle plate (c) obstructs the flow of the working fluid and lowers the transmission torque, thereby hindering the efficiency improvement of the transmission torque of the fluid coupling. ing.
The “fluid coupling” according to Japanese Patent Laid-Open No. 2005-188617 sufficiently reduces the input capacity coefficient in the low speed ratio area and suppresses the decrease in the input capacity coefficient in the speed ratio area other than the low speed ratio area.
Therefore, this fluid coupling includes an impeller, a turbine, a bearing 8, and a baffle plate. The impeller has an impeller shell, an impeller blade, and an impeller hub. The turbine is disposed opposite to the impeller in the fluid chamber, and includes a turbine shell that forms a torus together with the impeller shell, a turbine blade, and a turbine hub. The bearing rotatably supports the impeller hub with respect to the turbine hub. The baffle plate is provided in the torus and obstructs a part of the flow of the working fluid flowing in the torus. A hole for allowing the working fluid in the torus to flow out of the torus in the low speed ratio region is provided in the turbine shell adjacent to the baffle plate.

The “fluid coupling” according to Japanese Patent Laid-Open No. 2005-188618 brings the input capacity coefficient characteristic in the low speed ratio region close to flat without increasing the outer diameter size.
Therefore, this fluid coupling includes an impeller, a turbine, a bearing, and a baffle plate. The impeller has an impeller shell, an impeller blade, and an impeller hub. The turbine is disposed to face the impeller in the fluid chamber, and includes a turbine shell that forms a torus together with the impeller shell, a turbine blade, and a turbine hub. The bearing rotatably supports the impeller hub with respect to the turbine hub. The baffle plate is provided in the torus and obstructs a part of the flow of the working fluid flowing in the torus. And the chamfering part is formed in the front-end | tip part of an impeller blade and a turbine blade.

However, these fluid couplings are provided with a baffle plate to reduce the input capacity coefficient characteristics in the low speed ratio range and improve fuel efficiency. However, the flow of the working fluid is also inhibited in the high speed ratio range. As a result, the transmission torque is reduced.
"Fluid coupling" according to JP-A-2005-188617 "Fluid coupling" according to JP-A-2005-188618

  As described above, the conventional fluid coupling provided with the baffle plate has the above-described problems. The problem to be solved by the present invention is this problem, particularly in the low speed ratio range, especially when the vehicle is stopped by stepping on the brake and the engine is idling, and the flow of working fluid is obstructed to improve fuel efficiency. In addition, a fluid coupling having a baffle plate that acts so as not to disturb the flow of the working fluid is provided in the high speed ratio region.

  The fluid coupling according to the present invention includes a baffle plate as shown in FIG. That is, a structure having a pump impeller, a turbine runner, a piston, and a lock-up damper device, and having a baffle plate interposed between the pump impeller and the turbine runner, can obstruct the flow from the turbine runner to the pump impeller. It consists of. However, since it is the same as the conventional fluid coupling simply by obstructing the flow of the working fluid, the present invention has a structure in which a plurality of holes are provided in the baffle plate. Here, the specific shapes of the baffle plates and the holes are not limited. For example, as a specific shape of the baffle plate, there are a case where a plurality of holes are provided in the outer peripheral portion of the ring-shaped plate, and a case where a plurality of blades are provided radially at regular intervals.

  By the way, the direction of the working fluid that exits the turbine runner and flows into the pump impeller is different between the low speed ratio region and the high speed ratio region, and in the low speed ratio region, it flows at a certain angle with respect to the blades of the pump impeller. In the speed ratio region, it is almost parallel to the blade of the pump impeller. Therefore, the working fluid passes through the hole provided in the baffle plate, but the passage area of the hole with respect to the working fluid flowing from an oblique direction becomes small, and this becomes the flow resistance of the working fluid. On the other hand, in the high speed ratio region, the hole area that passes substantially perpendicularly to the holes of the baffle plate is increased, and therefore the passage resistance of the working fluid is reduced.

  In the fluid coupling of the present invention, a baffle plate is attached between the pump impeller and the turbine runner. The baffle plate has a plurality of holes. When idling, the flow of the working fluid that exits the turbine runner and enters the pump impeller is inclined with respect to the baffle plate. Therefore, since the working fluid passes through the holes of the baffle plate from an oblique direction, the passage area is reduced, and resistance to the flow is brought about.

  That is, when the flow of the working fluid is obstructed, the drag torque during idling is reduced, and the load on the engine that rotates the pump impeller is reduced. As a result, fuel efficiency is improved. On the other hand, in the high speed ratio region, the direction of the working fluid that exits from the turbine runner and enters the pump impeller is substantially perpendicular to the baffle plate, and the area through which the working fluid passes through the hole increases. Accordingly, the flow resistance of the working fluid decreases and the transmission torque increases.

  FIG. 1 is an embodiment showing a flow of a working fluid in a low speed ratio region of a fluid coupling according to the present invention. In the figure, 1 is a pump impeller, 2 is a turbine runner, 3 is a piston, and 4 is a lock-up damper device. If the outer shell 5 is filled with the working fluid and the outer shell 5 is rotated by the engine, the pump impeller 1 is rotated, and the turbine runner 2 is driven by the working fluid delivered by the rotation of the pump impeller 1. Rotate in the same direction.

  The turbine runner 2 is fixed to the turbine hub 6, and the lock-up damper device 4 is also attached to the turbine hub 6. The piston 3 is rotatably supported by the turbine hub 6, and the piston 3 is connected to the input side plate 7 of the lockup damper device 4 at the outer periphery thereof.

  By the way, the turbine runner 2 is rotated in the same direction by the pump impeller 1, and the working fluid circulates counterclockwise as indicated by an arrow. However, the flow of the working fluid is inhibited by the baffle plate 8. The baffle plate 8 is fixed to a pump hub 9 provided on the shaft side of the pump impeller 1, and the shape thereof is a ring body. A plurality of slit holes 10, 10. It is provided through.

  By the way, when the flow of the working fluid is slow during idling, the working fluid circulates and flows as indicated by an arrow, and the baffle plate 8 can obstruct this flow. That is, the working fluid hits the baffle plate 8 and most of it flows over the upper part. In the figure, a thick line indicates a large flow of the working fluid, and a thin line indicates a small flow. As shown by the thin line, a part of the slit hole 10 passes, but the flow of the working fluid is obstructed in this way, so that the drag torque is reduced and the load on the engine that rotates the pump impeller is reduced. As a result, fuel efficiency is improved.

  FIG. 2 shows the flow of the working fluid in the high speed ratio region in the fluid coupling according to the present invention. When the rotational speed of the pump impeller 1 increases, the flow of the working fluid increases, and accordingly, the rotational speed of the turbine runner 2 also increases. Although the working fluid circulates counterclockwise as shown in the figure, the working fluid hits the baffle plate 8 and easily passes through the slit hole 10. Accordingly, the working fluid flows more through the slit hole 10 and is returned to the pump impeller 1.

  Of course, not all of the circulating working fluid flows through the slit hole 10, but when the high speed ratio region is reached, the flow direction of the working fluid becomes substantially perpendicular to the baffle plate, and the slit through which the working fluid passes. The hole area expands. Therefore, the resistance received from the baffle plate 8 is reduced and can flow relatively smoothly. Accordingly, the resistance is reduced by that amount, so that the rotational speed of the turbine runner 2 is increased and the transmission torque is increased.

  Here, the baffle plate 8 is attached to the pump hub 9 by welding or the like, so that it rotates together with the pump impeller 1 and produces a rotational speed difference with the turbine runner 2. For this purpose, a bearing 12 is interposed between the turbine hub 6 that fixes the turbine runner 2 and the pump hub 9.

  In the state shown in FIG. 2, the turbine runner 2 starts to rotate as the pump impeller 1 rotates, and the working fluid passes through the opened slit hole 10. In this case, as the rotational speed of the turbine runner 2 increases, the flow direction of the working fluid comes to be substantially perpendicular to the baffle plate 8 and easily passes through the slit hole 10. That is, it becomes easier to pass through the slit hole 10 than at the time of idling, so that the transmission torque is increased by reducing the resistance to block the working fluid.

  Then, when the rotation of the pump impeller 1 is further increased and the rotational speed of the turbine runner 2 reaches a predetermined region, the piston 3 is operated and engaged with the front cover 13. When the piston 3 is engaged with the front cover 13, the rotational speed of the turbine runner 2 is rapidly increased, but the lockup damper device 4 is operated in order to reduce the impact torque at this time.

  In other words, the damper spring 14 is attached to the lockup damper device 4, and the shock torque is absorbed by the damper spring 14 being compressed and deformed. Thus, when the piston 3 is engaged with the front cover, the turbine runner 2 is directly rotated by the piston 3, and the rotational speed thereof becomes equal to that of the pump impeller 1. Therefore, the working fluid does not circulate as shown in FIG.

  FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 as viewed from the baffle plate 8 side. In the figure, 11 is a core of the pump impeller 1, 15 is a blade of the pump impeller 1, 8 is a baffle plate, and a plurality of slit holes 10, 10. It has been. Although the slit hole 10 of the baffle plate 8 in this embodiment is rectangular, it may have other shapes. For example, it can be a groove-shaped hole with an open outer periphery, and the blades inclined so that the flow resistance is large in the low speed ratio area (particularly during stall) and the flow resistance is small in the high speed ratio area are radial. It is also possible to configure as a baffle plate provided in

  Since the baffle plate 8 is fixed to the pump hub 9 as shown in FIGS. 1 and 2, the baffle plate 8 rotates together with the pump impeller 1, and the working fluid coming out of the turbine runner 2 hits the baffle plate 8 and a part thereof Passes through the slit holes 10, 10,. Of course, the other part enters the pump impeller 1 without hitting the baffle plate 8 and hits the blades 15, 15.

Figure 4 is in a fluid coupling having no baffles 8, and a low speed ratio range is low rotational speed N _T of the turbine runner with respect to the rotational speed N _P of the pump impeller, a turbine runner with respect to the rotational speed N _P of the pump impeller It is a schematic diagram showing the flow of the working fluid in the high speed ratio area where the rotational speed _NT is high.

  FIG. 2A shows the flow of the working fluid in the low speed ratio region, and the working fluid exiting from the turbine runner (T) enters the pump impeller (P) and strikes the blade 15. Similarly, FIG. 5B shows the flow of the working fluid in the high speed ratio region, and the working fluid exiting from the turbine runner (T) enters the pump impeller (P). At this time, in the low speed ratio region, the flow of the working fluid exiting from the turbine runner 2 is incident on the blade 15 of the pump impeller 1 in an oblique direction as shown in FIG. However, when the rotational speed ratio increases, the working fluid enters the blade 15 of the pump impeller 1 almost in parallel.

  That is, since there is no baffle plate 8 between the turbine runner (T) and the pump impeller (P), the working fluid flows smoothly in any case. The smooth flow of the working fluid in the low speed ratio region inevitably consumes energy, and as a result, the fuel consumption during idling deteriorates.

  FIG. 5 shows a conventional fluid coupling in which a baffle plate 8 is provided, but the baffle plate 8 is not provided with a slit hole. Therefore, the working fluid flowing out from the turbine runner (T) hits the baffle plate 8. This is the same in both the low speed ratio area and the high speed ratio area, but the low speed ratio area hits from an oblique direction. For this reason, fuel efficiency during idling, which is a low speed ratio range, is improved, but transmission torque is also suppressed in a high speed ratio range.

  FIG. 6 shows a case of the fluid coupling according to the present invention. The baffle plate 8 has a slit hole 10 and is a schematic view showing a state in which the working fluid flows through the slit hole 10. (A) shows the flow of the working fluid in the idling state in the low speed ratio region. The working fluid coming out of the turbine runner (T) hits the baffle plate 8 and partly passes through the slit hole 10. FIG. 4B shows the flow of the working fluid in the high speed ratio region. The working fluid that exits from the turbine runner (T) hits the baffle plate 8, and part of it passes through the slit hole 10 and passes through the pump impeller (P). Enter.

  Here, the working fluid passes through the slit hole 10 of the baffle plate 8, but in the low speed ratio region, the direction of the working fluid exiting from the turbine runner (T) is an oblique direction, and hits the baffle plate 8 from the oblique direction. . Therefore, it also enters the slit hole 10 formed in the baffle plate 8 from an oblique direction and passes therethrough. For this reason, the passage area of the slit hole 10 is reduced, and the amount of working fluid passing therethrough is small. On the other hand, the high speed ratio region is substantially perpendicular to the baffle plate 8 and can pass through the slit hole 10 almost perpendicularly. For this reason, the passage area is large and the amount of working fluid passing through is large.

  In this way, the flow of the working fluid is suppressed by the baffle plate 8 being interposed between the turbine runner (T) and the pump impeller (P), and the slit of the baffle plate 8 is particularly low in the low speed ratio region. The flow of the working fluid is greatly suppressed by reducing the passage area of the hole 10. The slow flow of the working fluid inevitably reduces energy consumption and improves fuel efficiency during idling. On the other hand, in the high speed ratio region, the passage area of the slit hole 10 is enlarged, so that the working fluid flows through the enlarged slit hole 10 and a large transmission torque can be obtained.

  However, even if the slit hole 10 is formed in the baffle plate 8 as in the present invention, the transmission torque can be suppressed as compared with a fluid coupling that does not include the baffle plate 8 as shown in FIG. However, this is also until the piston 3 operates and engages with the front cover 13, and the fuel consumption can be reduced in total if the fuel consumption during idling is suppressed.

FIG. 7 shows a speed ratio of a fluid coupling having no baffle plate, a fluid coupling having a baffle plate, and a fluid coupling having a baffle plate having a slit hole (rotational speed N _{T of} turbine runner / pump impeller it is a graph showing the magnitude of the rotational speed N _P) capacity for the coefficient of the (transmission torque). As is apparent from the figure, the capacity coefficient (transmission torque) increases without any baffle plate regardless of the speed ratio. In contrast, when the slit hole is formed in the baffle plate and when the slit hole is not provided, there is almost no difference when idling with a low speed ratio, but as the speed ratio increases, the capacity coefficient (transmission) (Torque) will increase.

  This indicates that the presence effect of the baffle plate 8 is large because the smaller the capacity coefficient (transmission torque) in the low speed ratio region leads to improved fuel efficiency. It is clear that the slit hole effect can be obtained in the high speed ratio region because the capacity coefficient (transmission torque) is larger when the slit hole is formed in the baffle plate.

In the fluid coupling according to the present invention, in a low speed ratio range in which a small amount of the working fluid passes through the slit hole of the baffle plate. In the fluid coupling according to the present invention, in the high speed ratio region where a part of the working fluid passes through the slit hole of the baffle plate. AA sectional drawing of FIG. The schematic diagram which shows the flow of the working fluid from a turbine runner to a pump impeller in the case of the fluid coupling which does not have a baffle plate. The schematic diagram which shows the flow which the working fluid which came out of the turbine runner hits a baffle plate in the case of the fluid coupling provided with the baffle plate. The schematic diagram which shows the flow through which the working fluid which came out of the turbine runner passes the slit hole in the case of the fluid coupling provided with the baffle plate which has a slit hole. The graph which shows the magnitude | size of the capacity | capacitance coefficient (transmission torque) with respect to the speed ratio of the fluid coupling which does not have a baffle plate, the fluid coupling which has a baffle plate, and the fluid coupling which has the baffle plate which formed the slit hole It is. Conventional fluid coupling with baffle plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump impeller 2 Turbine runner 3 Piston 4 Lockup damper device 5 Outer shell 6 Turbine hub 7 Input side plate 8 Baffle plate 9 Pump hub
10 Slit hole
11 core
12 bearings
13 Front cover
14 Damper spring
15 blade

Claims (3)

The outer shell is filled with a working fluid, and a turbine runner that rotates through the working fluid by a pump impeller that rotates with the engine, and operates when the rotational speed of the turbine runner reaches a certain level or more and engages with the front cover. Further, it absorbs impact torque generated when the piston engages with the front cover and elastically connects the turbine runner. A fluid coupling provided with a lock-up damper device for absorbing, wherein a baffle plate is attached to a pump hub of the pump impeller, and the baffle plate has a plurality of holes, and the fluid coupling includes a baffle plate. The fluid coupling provided with the baffle plate according to claim 1, wherein a plurality of slit holes are provided in an outer peripheral portion of the baffle plate. The fluid coupling provided with the baffle plate according to claim 1 or 2, wherein the baffle plate is configured such that a plurality of blades having a predetermined orientation are provided radially at regular intervals.

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