JP5609897B2 - Torque converter - Google Patents

Description

  The present invention relates to a torque converter for an automatic transmission mounted on a vehicle, and more particularly to a torque converter having a lock-up clutch, and belongs to the technical field of a vehicle transmission.

  A torque converter that is incorporated in an automatic transmission and transmits engine output to a transmission mechanism is disposed opposite to the pump that rotates integrally with the crankshaft of the engine, and is driven by a fluid through the pump. A turbine, and a stator that is disposed inside a facing portion of the pump and the turbine and that increases torque. Further, in the case of the torque converter, a half part on the engine side in the axial direction is constituted by the front cover, and a half part on the side opposite to the engine is constituted by the pump shell of the pump.

  In addition, in order to improve the fuel efficiency of the engine, a lockup that directly connects the pump and the turbine is used except when starting using torque increasing action or when shifting that requires the relative rotation of the pump and turbine. A clutch may be provided. Further, in this case, the piston of the lockup clutch (lockup piston) is disposed opposite to the front cover, and hydraulic pressure for fastening the lockup clutch (fastening hydraulic pressure) is supplied between the lockup piston and the front cover. A hydraulic chamber may be formed.

  In the torque converter having the above-described configuration, the lockup piston is applied to the friction plate by supplying the tightening oil pressure to the hydraulic chamber, and the lockup clutch is fastened. By discharging, the fastening force by the lock-up piston is released and the lock-up clutch is released. That is, the engagement and release of the lockup piston can be controlled by controlling the engagement hydraulic pressure, and the slip control of the lockup clutch can be performed by adjusting the engagement hydraulic pressure or the engagement force supplied to the hydraulic chamber.

  However, in the case of the torque converter, oil for transmitting power between the pump and the turbine is filled. The oil pressure (internal pressure) in this case is the rotational speed of the pump, the rotational speed of the turbine, And it fluctuates greatly with changes in the speed ratio of the pump and the turbine. This internal pressure acts on the lockup piston from the anti-hydraulic chamber side, and reduces the fastening force acting on the friction plate with respect to a constant fastening hydraulic pressure, so that the precision of lockup clutch fastening control and slip control is reduced. . Also, considering the fluctuation of the internal pressure that decreases the fastening force in this way, it is necessary to set the fastening hydraulic pressure higher in order to cope with the state where the internal pressure becomes the highest, so a high-capacity hydraulic pump is required, and as a result As a result, an increase in engine load and a deterioration in fuel consumption are caused.

  A structure of a torque converter that can solve this problem is disclosed in FIG. As shown in FIG. 8, in this torque converter 101, the lock-up piston 165 is disposed so as to extend radially outward from a hub 130 disposed at the center of the front cover 111. A hydraulic chamber 104 to which a fastening hydraulic pressure is supplied is formed between the front cover 111 and the front cover 111. The lock-up piston 165 moves in the axial direction according to the supply state of the engagement hydraulic pressure, whereby the engagement state of the lock-up clutch 160 changes.

  In the technique of Patent Document 1, another plate member (hereinafter referred to as “internal pressure canceling plate”) 150 is provided on the opposite side of the front cover 111 with the lock-up piston 165 interposed therebetween. The internal pressure cancellation plate 150 is also disposed so as to extend radially outward from the hub 130 along the lock-up piston 165.

  By providing the internal pressure cancellation plate 150 in this way, a space (hereinafter referred to as “internal pressure cancellation chamber”) 106 in which the space between the internal pressure cancellation plate 150 and the lock-up piston 165 stably supplies hydraulic pressure is provided. Can function as. Therefore, the oil is stably supplied to the internal pressure canceling chamber 106 to prevent the internal pressure in the case from acting on the lockup piston 165 from the counter-hydraulic chamber side, and the lockup clutch 160 is engaged due to fluctuations in the internal pressure. The fluctuation of force can be suppressed, and this makes it possible to precisely perform the engagement control and slip control of the lockup clutch 160.

US Patent Application Publication No. 2010/0084238

  By the way, in the above configuration of Patent Document 1, the internal pressure cancellation plate 150 is externally fitted to the hub 130 and is counteracted by a spring 192 provided on a connecting member 190 that connects the internal pressure cancellation plate 150 and the lockup piston 165. While being urged toward the engine side, the snap ring 198 attached to the hub 130 prevents movement toward the anti-engine side, thereby fixing it at a predetermined position in the axial direction.

  However, when the internal pressure cancel plate 150 is assembled to have such a mounting structure, the internal pressure cancel plate 150 is fitted into the outer peripheral portion of the hub 130, and the internal pressure cancel plate is fitted to the lock-up piston 165 previously fitted to the hub 130. 150 is connected by the connecting member 190, and then the internal pressure canceling plate 150 is pushed toward the lock-up piston 165 against the urging force of the spring 192 of the connecting member 190, and the outer circumferential surface of the hub 130 is maintained while keeping this pushed state. The complicated work of mounting the snap ring 198 in the snap ring groove is forced.

  Further, when the internal pressure cancel plate 150 is attached using the snap ring 198 as described above, a step of forming a snap ring groove in the hub 130 in advance is required.

  Further, in the mounting structure of Patent Document 1, when the hub 130 rotates at a high speed, there is a concern that the snap ring 198 may be dropped from the snap ring groove by opening so as to expand in the radial direction due to centrifugal force. In order to avoid this, it is conceivable to form the snap ring groove deeply. However, in this case, the strength is reduced by the amount that the thickness of the hub 130 is reduced in the groove forming portion. On the other hand, in order to avoid a decrease in strength, it is conceivable to increase the thickness of the hub 130 by the depth of the snap ring groove. In this case, however, an increase in weight and a deterioration in fuel consumption are caused.

  Therefore, the present invention provides a simple, while suppressing a decrease in strength and an increase in weight when an internal pressure cancellation plate is provided for suppressing a change in engagement force of a piston of a lockup clutch with a change in internal pressure. It is an object of the present invention to provide a torque converter capable of assembling an internal pressure cancel plate in a process and in a reliable support state.

  In order to solve the above problems, the present invention is configured as follows.

First, the invention according to claim 1 of the present application is
A case having a front cover coupled to an output shaft of the engine; and a lock-up clutch housed in the case; and fastening of the lock-up clutch between the front cover and a piston of the lock-up clutch. A torque converter in which a hydraulic chamber to which hydraulic pressure is supplied is formed, and an internal pressure cancellation plate that forms an internal pressure cancellation chamber between the piston and the piston on the opposite side of the hydraulic chamber;
The internal pressure canceling plate is fixed to the front cover itself or to a member separate from the piston and fixed to the front cover by welding from the axial direction. .

The invention according to claim 2 is the torque converter according to claim 1,
The welded portion between the internal pressure cancellation plate and the front cover itself or the member fixed to the front cover is disposed radially inward from the inner peripheral edge of the piston.

Furthermore, the invention according to claim 3 is the torque converter according to claim 1 or 2, wherein
It said member which is fixed to the front cover, and wherein the oil path communicating with the hydraulic chamber is an oil path constituting member which is fixed to the front cover so as to form between the front cover To do.

Furthermore, the invention according to claim 4 is the torque converter according to any one of claims 1 to 3, wherein
The inside of the case and the internal pressure cancellation chamber are communicated with each other, and a communication hole is provided in which an area is reduced when the lockup clutch is released compared to when the lockup clutch is released.

The invention according to claim 5 is the torque converter according to claim 4,
The piston is provided to be movable in the axial direction according to the magnitude of the fastening hydraulic pressure,
The piston includes a cylindrical portion extending in the axial direction,
The communication hole is formed at a position where an area of a portion of the cylindrical portion that is blocked by an outer peripheral end portion of the internal pressure canceling plate is larger when the lockup clutch is released than when the lockup clutch is released. It is characterized by being.

  With the above configuration, according to the invention of each claim of the present application, the following effects can be obtained.

First, according to the invention described in claim 1 of the present application, the inner pressure cancel plate for suppressing the fastening force of the lockup clutch from fluctuating with the fluctuation of the inner pressure is formed by the front cover itself by welding in the axial direction. Or, since it is fixed to a member fixed to the front cover , the inner pressure canceling plate is more reliably supported than in the case of assembling in a dismountable state using a snap ring or the like as in the prior art described above. Can be obtained.

  Further, according to the present invention, with respect to the assembly of the internal pressure canceling plate, it is possible to omit the connecting member with a spring and the snap ring as in the prior art, and the spring biasing force as in the prior art. On the other hand, the internal pressure cancel plate can be assembled relatively easily without requiring a complicated assembly process of mounting the snap ring while pushing the internal pressure cancel plate toward the lock-up piston. Moreover, since it is not necessary to form a snap ring groove for assembling the internal pressure cancel plate, the weight is reduced by increasing the wall thickness to avoid strength reduction by conversely forming the snap ring groove and conversely. Can be avoided.

Further, according to the present invention, since the welding operation of the internal pressure cancel plate to the front cover itself or a member fixed to the front cover is performed from the axial direction, the welding operation interferes with the radially outer member. You can avoid that.

According to the second aspect of the present invention, the welded portion between the internal pressure cancellation plate and the front cover itself or a member fixed to the front cover is more radial than the inner peripheral edge of the piston of the lockup clutch. Since the inner pressure cancel plate is welded to the front cover itself or a member fixed to the front cover, the work can be performed without interfering with the piston. There is no need to provide a working opening.

  Furthermore, according to the present invention, since the piston has a large inner diameter as described above, the weight of the piston is reduced, so that the response of the piston to the fastening hydraulic pressure is improved, and the fastening control of the lockup clutch and Slip control can be performed precisely.

Further, according to the invention described in claim 3, as the member which is fixed to the front cover, which is fixed to the said front cover so as to form the oil passage of the fastening pressure between the front cover oil The internal pressure cancellation plate can be simply fixed using the path constituent member.

  According to the fourth aspect of the present invention, the area of the communication hole that communicates the inside of the case with the internal pressure cancellation chamber is reduced when the lockup clutch is in the engaged state compared to when the lockup clutch is in the released state.

  For this reason, when the lockup clutch is released, even when the amount of oil in the case or the internal pressure cancellation chamber is small, the oil is released into the internal pressure cancellation chamber relatively quickly through the communication hole having a relatively large area. Therefore, regardless of the operating state, the oil pressure in the internal pressure canceling chamber, that is, the pressure resisting the fastening force of the piston can be stabilized. Further, even during traveling such as when the internal pressure in the case increases, the hydraulic pressure in the internal pressure cancellation chamber isolated by the internal pressure cancellation plate can be kept sufficiently lower than the internal pressure. In this way, since the hydraulic pressure in the internal pressure cancellation chamber that resists the fastening force of the piston is low and stable, the fastening hydraulic pressure required when the lockup clutch is fastened can be set low, thereby reducing the capacity of the hydraulic pump. Reduction, reduction of engine load, and improvement of fuel efficiency can be achieved.

  On the other hand, in the engaged state of the lockup clutch, there is little need for oil supply to the internal pressure cancellation chamber, and the area of the communication hole is relatively small, so that oil is wasted due to excessive supply to the internal pressure cancellation chamber. Can be suppressed. Therefore, the oil can be effectively used for other uses in the same hydraulic system without increasing the capacity of the hydraulic pump.

  Furthermore, when the invention according to claim 5 is applied to the invention according to claim 4, the communication hole is provided in the cylindrical portion of the piston of the lock-up clutch, and the communication hole is formed at the outer peripheral end of the internal pressure cancellation plate. Because the area of the part to be blocked changes with the movement of the piston in the axial direction according to the magnitude of the fastening hydraulic pressure, it changes so as to be larger in the engaged state than in the released state of the lockup clutch. The movement of the piston can be used for controlling the area of the communication hole.

It is sectional drawing of the torque converter which concerns on one Embodiment of this invention. It is sectional drawing which expands and shows the outer periphery part of the internal pressure cancellation plate in the releasing state of a lockup clutch, and its periphery. It is sectional drawing which expands and shows the outer periphery part of the internal pressure cancellation plate in the fastening state of a lockup clutch, and its periphery. It is sectional drawing which expands and shows the shape of the spline in the front-end | tip part of a turbine hub. It is sectional drawing which shows the assembly procedure of the torque converter shown in FIG. It is sectional drawing which shows the assembly procedure of the torque converter shown in FIG. It is sectional drawing which shows the assembly procedure of the torque converter shown in FIG. It is sectional drawing which shows the prior art example of the torque converter provided with the internal pressure cancellation plate.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 shows a torque converter 1 according to the present embodiment. The torque converter 1 has a case 10 that forms an outer shell thereof. The front cover 11 constituting the engine-side half of the case 10 is connected to an engine crankshaft (not shown) via a connecting portion 12 fixed to the outside of the central portion in the radial direction of the front cover 11. Thus, the torque converter 1 is driven by the engine.

  In the following description, for the sake of convenience, the engine side (the right side in the figure) is the front, and the non-engine side (the left side in the figure) is the rear.

  The torque converter 1 includes, as main components, a donut-shaped torus T formed by a pump, a turbine, and a stator, a one-way clutch OWC, a lock-up clutch (hereinafter also simply referred to as “clutch”) 60, and a lock-up damper. (Hereinafter also referred to simply as “damper”). These components 60, LD, OWC, and T are accommodated in the case 10, and the case 10 is filled with oil as a fluid.

  In FIG. 1, the detailed illustration of constituent members of the torus T (pump, turbine, and stator), one-way clutch OWC, and damper LD is omitted for easy understanding of the invention.

  The pump has a pump shell 21 that forms an outer shell thereof, and the pump shell 21 constitutes the rear half of the case 10. A sleeve 23 extending rearward is provided at the inner peripheral end of the pump shell 21, and the tip of the sleeve 23 is associated with a gear-type oil pump (not shown) disposed behind the torque converter 1. As a result, the oil pump is driven through the case 10 and the sleeve 23 by the rotation of the crankshaft.

  Further, the turbine is rotatably disposed in front of the pump 10. The inner peripheral portion of the turbine is constituted by a turbine hub 30, and the driving force of the turbine is transmitted to the transmission mechanism of the automatic transmission by the turbine shaft 25 spline-fitted to the inner peripheral end portion of the turbine hub 30. It has become. As shown in FIG. 4, the rear end portion of the spline 32 of the turbine hub 30 is a chamfered portion 33 that is largely inclined forward toward the turbine shaft 25 side, and a tooth root portion 34 of the chamfered portion 33. Has a rounded shape, so that the stress applied to the rear end portion of the turbine hub 30 is relieved.

  As shown in FIG. 1, the one-way clutch OWC supports the stator and realizes a torque increasing action by the stator, and the inner peripheral surface of the inner race 36 of the one-way clutch OWC The oil pump sleeve 24 which is a part of the transmission case is spline-fitted to the tip.

  The stator rotates freely when the one-way clutch OWC idles when it receives a rotational force in one direction due to the flow of fluid in the torus T, and when the stator receives a rotational force in the other direction, The way clutch OWC is fixed by being locked. At this time, a torque increasing action occurs, the torque input from the engine to the pump is increased, and the torque is output from the turbine to the turbine shaft 25.

  In this case, this torque increasing action is usually obtained when the speed ratio is in the range of 0 to 0.8 to 0.9, and the torque ratio (torque increase rate) is maximized when the speed ratio is 0. .

  As described above, the oil for forming a fluid flow in the torus T is supplied into the case 10 through the oil passage 24a formed between the turbine shaft 25 and the oil pump sleeve 24, and the oil pump sleeve 24 is supplied. Is discharged through an oil passage 23 a formed between the sleeve 23 and the sleeve 23.

  On the other hand, the clutch 60 includes a clutch hub 61 and a clutch drum 62 disposed concentrically, and a plurality of friction plates disposed between the hub 61 and the drum 62 and alternately engaged with them. 63 and a piston 65, and the clutch drum 62 is fixed to the inner surface of the front cover 11 by welding. Further, a hydraulic chamber 4 is formed between the back of the piston 65, that is, between the piston 65 and the front cover 11, to which the fastening hydraulic pressure of the lockup clutch is supplied.

  When hydraulic pressure is introduced into the hydraulic chamber 4 from an oil passage 7 provided inside the turbine shaft 25 through an oil passage 40a formed along the inner surface of the front cover 11, the piston 64 A plurality of friction plates 63 are pressed against the retainer 68 and the clutch 60 is fastened.

  The interior of the turbine shaft 25 is constituted by an oil hole 27 penetrating in the axial direction, and the oil hole 27 communicates with the hydraulic chamber 4 by a pipe member 28 fitted in the oil hole 27. The oil passage 7 and an outer oil passage 8 communicating with an internal pressure canceling chamber 6 described later are partitioned.

  Further, the damper LD is coupled to the hub 61 of the clutch 60, and when the clutch 60 is engaged, the rotation of the front cover 11, that is, the rotation of the crankshaft, is transmitted to the damper LD via the clutch 60. It is inputted and transmitted to the turbine while compressing the damper spring of the damper LD.

  Here, the operation of the torque converter 1 will be described. First, when the clutch 60 is not engaged, such as when starting or shifting, the fluid circulating in the torus T is pumped by a pump that rotates integrally with the crankshaft of the engine. The turbine is driven through the turbine shaft 25, and power is transmitted to the transmission mechanism through the turbine shaft 25. In that case, in the converter region where the speed ratio is about 0.8 to 0.9 or less, the engine output torque is increased and output to the transmission mechanism by the torque increasing action of the stator.

  Further, when the engagement hydraulic pressure is supplied to the hydraulic chamber 4 of the clutch 60 through the oil passages 7, 40 a and the like in an operation state other than at the time of starting, shifting, etc., the clutch 60 is engaged and the front cover 11 The turbine is connected via a damper LD, and the engine output torque is directly transmitted from the crankshaft to the turbine via the case 10, the clutch 60, and the damper LD. In this case, the power is transmitted to the speed change mechanism without passing through the fluid, so that the torque transmission efficiency is improved compared to when the clutch 60 is not engaged, and the fuel efficiency of the engine is improved.

  When the clutch 60 is engaged, in order to suppress a shock when the clutch 60 is engaged, the engagement hydraulic pressure supplied to the hydraulic chamber 4 is controlled so that the clutch 60 is once slipped. When a plurality of friction plates 63 of the clutch 60 start to contact and torque transmission is started, the damper spring of the damper LD is compressed to absorb the shock at the time of torque transmission, As a result, the clutch 60 is smoothly engaged.

  Hereinafter, a characteristic configuration of the torque converter 1 according to the present embodiment will be described.

  In the present embodiment, the oil passage configuration plate 40 is interposed between the turbine hub 30 and the piston 65. The oil passage constituting plate 40 is an annular plate member disposed substantially along the radial direction, and is fixed to the front cover 11 by welding from the axial direction (see FIG. 5). This welding is performed by spot welding at a plurality of locations in the circumferential direction, for example.

  A plurality of grooves 41 extending in a substantially radial direction are formed on the surface of the oil path constituting plate 40 on the front cover 11 side, and the groove 41 is formed between the oil path constituting plate 40 and the front cover 11. In addition, an oil passage 40 a communicating with the hydraulic chamber 4 is formed. However, the oil passage 40 a may be formed by providing a similar groove in the front cover 11 instead of providing the groove 41 in the oil passage constituting plate 40.

  In addition, the front portion of the turbine hub 30 is fitted in the inner peripheral portion of the oil passage constituting plate 40 via, for example, an annular spring 39. On the other hand, an annular seal member 42 interposed between the outer periphery of the oil passage constituting plate 40 and the inner periphery of the piston 65 is attached. Furthermore, locking recesses 44 for locking the inner peripheral end of the piston 65 are provided at a plurality of locations in the circumferential direction on the outer peripheral portion of the oil passage constituting plate 40.

  The piston 65 includes an inner cylindrical portion 70 extending in the axial direction, a hydraulic pressure receiving portion 72 extending radially outward from the front end portion of the inner cylindrical portion 70, and an axially extending rearward from the outer peripheral end portion of the hydraulic pressure receiving portion 72. The outer cylindrical portion 74 and a pressing portion 76 extending radially outward from the rear end portion of the outer cylindrical portion 74 are provided.

  The hydraulic pressure receiving portion 72 is disposed to face the front cover 11, and the hydraulic chamber 4 is formed between the hydraulic pressure receiving portion 72 and the front cover 11. Thus, for example, when the fastening hydraulic pressure is supplied to the hydraulic chamber 4 in the released state of the clutch 60 shown in FIG. 2, the piston 65 that has received the fastening hydraulic pressure by the hydraulic pressure receiving portion 72 slides rearward in the axial direction. As shown in FIG. 3, the friction plate 63 is pressed toward the retainer 68 by the pressing portion 76 of the piston 65, and the clutch 60 is fastened. As described above, the piston 65 is movable in the axial direction in accordance with the magnitude of the fastening hydraulic pressure supplied to the hydraulic chamber 4.

  As shown in FIG. 1, a locking portion 78 that is locked to the outer peripheral portion of the oil passage constituting plate 40 is provided on the inner peripheral portion of the piston 65. Specifically, the locking portion 78 protrudes radially inward from a plurality of locations in the circumferential direction corresponding to the locking recess 44 of the oil passage constituting plate 40 at the rear end portion of the inner cylindrical portion 70. And is locked in the locking recess 44.

  An annular seal member 79 is attached to the outer peripheral portion of the outer cylindrical portion 74 at the front end thereof, and the seal member 79 allows the outer cylindrical portion 74 of the piston 65 and the inner peripheral end portion of the clutch drum 62 to be connected. Sealing performance is ensured. 2 and 3, the outer cylindrical portion 74 is provided with a communication hole 80. The configuration of the communication hole 80 will be described later.

As shown in FIG. 6, when the outer diameter of the piston 65 is D1 and the inner diameter is D2, the inner diameter D2 is not less than ½ of the outer diameter D1. More specifically, the relationship between the outer diameter D1 and the inner diameter D2 is, for example,
0.5 <D2 / D1 <0.7
It is preferable that As described above, the piston 65 is formed to have a large inner diameter, and thus the weight of the piston 65 is reduced. Therefore, the response of the piston 65 to the engagement hydraulic pressure is enhanced, and the engagement control and slip control of the clutch 60 can be performed precisely.

  On the other hand, the clutch drum 62 includes a cylindrical portion 82 that extends in the axial direction and an annular flange portion 84 that extends radially inward from the front end portion of the cylindrical portion 82, and the flange portion 84 is attached to the front cover 11. It is fixed by welding from the direction. This welding is performed by spot welding at a plurality of locations in the circumferential direction, for example.

  Returning to FIG. 1, an internal pressure canceling plate 50 is disposed behind the piston 65, and the internal pressure canceling plate 50 forms an internal pressure canceling chamber 6 between the piston 65 on the side opposite to the hydraulic chamber 4. Forming.

  The internal pressure cancel plate 50 includes an annular inner plate portion 52 disposed substantially along the radial direction, a cylindrical portion 54 that extends axially forward from the outer peripheral edge of the inner plate portion 52, and a front end of the cylindrical portion 54. And an annular outer plate portion 56 extending radially outward from the portion.

  The inner plate portion 52 of the internal pressure canceling plate 50 is disposed along the oil passage constituting plate 40 so as to face the oil passage constituting plate 40, and, like the oil passage constituting plate 40, for example, via an annular spring 49. And is fitted on the front portion of the turbine hub 30.

  Further, as shown in FIG. 7, the inner plate portion 52 is fixed to the oil passage constituting plate 40 by welding from the axial direction. This welding is performed by spot welding at a plurality of locations in the circumferential direction, for example. The welded portion 90 between the inner plate portion 52 and the oil passage constituting plate 40 is disposed radially inward from the inner peripheral edge portion of the piston 65. Therefore, since the welding operation can be performed without interfering with the piston 65, it is not necessary to provide an opening for the welding operation in the piston 65 in advance.

  As shown in FIG. 1, the cylindrical portion 54 of the internal pressure cancellation plate 50 is disposed on the radially outer side of the inner cylindrical portion 70 along the inner cylindrical portion 70 of the piston 65. The outer plate portion 56 of the inner pressure cancellation plate 50 is disposed along the hydraulic pressure receiving portion 72 of the piston 65 so as to face the hydraulic pressure receiving portion 72, and the tip of the outer plate portion 56 is the outer cylinder of the piston 65. It is arranged close to the portion 74. For example, a lip seal 58 as shown by a two-dot chain line in FIGS. 2 and 3 may be provided at the tip of the outer plate portion 56, whereby the outer cylindrical portion 74 of the piston 65 and the inner pressure canceling plate 50 may be provided. The lip seal 58 can be prevented from coming into contact with the peripheral edge of the communication hole 80 and being worn.

  The internal pressure cancellation chamber 6 is formed between the outer plate portion 56 and the hydraulic pressure receiving portion 72 arranged in this way. The oil is stably supplied to the internal pressure canceling chamber 6 to prevent the internal pressure in the case 10 due to the oil supplied to the torus T from acting on the piston 65 from the counter-hydraulic chamber side. Therefore, it is possible to control the engagement control and slip control of the clutch 60 more precisely.

  Here, the space in which the internal pressure is generated in the case 10 is a space that is behind the internal pressure cancel plate 50 and a space that is radially outside the outer cylindrical portion 74 of the piston 65, and these are combined below. The space is defined as “internal pressure chamber 2”.

  The internal pressure cancellation chamber 6 communicates with the internal pressure chamber 2 through a communication hole 80 provided in the outer cylindrical portion 74 of the piston, and oil is supplied from the internal pressure chamber 2 to the internal pressure cancellation chamber 6 through the communication hole 80. It is like that.

  In addition to the communication hole 80, a communication hole may be provided in the portion indicated by the symbol H of the inner plate portion 52, so that the oil can be supplied to the internal pressure cancellation chamber 6 more quickly. it can.

  The internal pressure cancellation chamber 6 is connected to the oil passage 8 outside the turbine shaft 25 through a communication hole 31 that penetrates the turbine hub 30 in the radial direction and an insertion hole 26 that penetrates the turbine shaft 25 in the radial direction. The oil in the internal pressure cancellation chamber 6 is returned to the oil pump side through the insertion holes 26 and 31 and the oil passage 8.

  In the released state of the clutch 60 shown in FIG. 2, the communication hole 80 is completely opened without being blocked by the outer peripheral end portion of the internal pressure canceling plate 50. In contrast, in the engaged state of the clutch 60 shown in FIG. 3, the communication hole 80 is partially blocked by the outer peripheral end portion of the internal pressure cancellation plate 50, and the closed portion of the communication hole 80 is Is approximately half the area of the entire communication hole 80, for example.

  In this way, the communication hole 80 is larger in the outer cylindrical portion 74 of the piston 65 when the area closed by the outer peripheral end of the internal pressure cancellation plate 50 is in the engaged state than in the released state of the clutch 60. It is formed in the position. Thus, the area of the communication hole 80 is reduced when the clutch 60 is engaged compared to when the clutch 60 is released using the movement of the piston 65.

  Therefore, in the released state of the clutch 60, even when the amount of oil in the internal pressure chamber 2 or the internal pressure cancellation chamber 6 is small, the internal pressure cancellation chamber 6 enters the internal pressure cancellation chamber 6 through the communication hole 80 having a relatively large area. Since oil can be introduced relatively quickly, the oil pressure in the internal pressure canceling chamber 6, that is, the pressure resisting the fastening force of the piston 65 can be stabilized regardless of the operating state. Even when the internal pressure of the internal pressure chamber 2 is increased, the oil is introduced into the internal pressure cancellation chamber 6 isolated by the internal pressure cancellation plate 50 and the outer cylindrical portion 74 of the piston 65 only through the communication hole 80. Therefore, the hydraulic pressure in the internal pressure cancellation chamber 6 is stabilized in a state lower than the internal pressure. Thus, since the hydraulic pressure of the internal pressure canceling chamber 6 that resists the fastening force of the piston 65 is stable in a low state, the fastening hydraulic pressure required when the clutch 60 is fastened can be set low. The capacity of the engine can be reduced, the engine load can be reduced, and the fuel efficiency can be improved.

  On the other hand, in the engaged state of the clutch 60, it is assumed that the oil is sufficiently supplied to the internal pressure chamber 2 and the internal pressure cancellation chamber 6, so that the need for further oil supply to the internal pressure cancellation chamber 6 is scarce. Further, as described above, since the oil supplied to the internal pressure cancellation chamber 6 is returned to the oil pump side through the outer passage 8 in the turbine shaft 25, the excessive oil supplied to the internal pressure cancellation chamber 6 is wasted. Will be. In the present embodiment, the waste of oil due to excessive supply to the internal pressure cancellation chamber 6 is reduced by making the area of the communication hole 80 relatively small as described above in order to cope with such a state of the fastening state. Can be suppressed. Therefore, the oil can be effectively used for other uses in the same hydraulic system without increasing the capacity of the oil pump, and for example, the amount of lubricating oil of the transmission mechanism during traveling can be sufficiently secured. .

  In this embodiment, the closed portion of the communication hole 80 by the outer peripheral end portion of the internal pressure cancellation plate 50 does not occur in the released state of the clutch 60. However, the communication hole by the outer peripheral end portion of the internal pressure cancellation plate 50 is not provided. As long as the area of the closed portion 80 is configured to be larger in the engaged state than in the released state of the clutch 60, a part of the communication hole 80 is at the outer peripheral end portion of the internal pressure canceling plate 50 even in the released state. It may be configured to be blocked.

  The assembly procedure of the torque converter 1 until the assembly of the internal pressure cancellation plate 50 is completed will be described with reference to FIGS.

  First, as shown in FIG. 5, the oil path constituting plate 40 and the flange portion 84 of the clutch drum 62 are assembled to the front cover 11 by welding from the axial direction.

  Next, as shown in FIG. 6, the piston 65 is connected to the oil passage constituting plate 40 and the clutch drum so that the engaging portion 78 of the piston 65 is engaged with the engaging recess 44 of the oil passage constituting plate 40. Fit between 62 and assemble.

  Subsequently, as shown in FIG. 7, the internal pressure canceling plate 50 is assembled to the oil passage constituting plate 40 by welding from the axial direction.

  Thus, according to this embodiment, the assembly work of the torque converter 1 is facilitated because the assembly work of the oil passage constituting plate 40, the clutch drum 62, the piston 65, and the internal pressure cancellation plate 50 is all performed from the axial direction. improves.

  In addition, since the internal pressure cancel plate 50 is fixed by welding, a more reliable support state of the internal pressure cancel plate 50 can be obtained as compared with a case where the internal pressure cancel plate 50 is assembled in a disassembleable state using a support member such as a snap ring.

  Further, when assembling the internal pressure cancel plate 50, a member such as a connecting member with a spring or a snap ring as in the prior art described above can be omitted, and the internal pressure against the biasing force of the spring as in the prior art can be omitted. The internal pressure cancel plate 50 can be assembled relatively easily without requiring a complicated assembly process of attaching the snap ring while pushing the cancel plate toward the piston side.

  Moreover, since the internal pressure cancellation plate 50 is welded to the oil passage constituting plate 40 from the axial direction, it is possible to avoid interference with members such as the piston 65 disposed radially outside during the welding operation. it can. Therefore, it is not necessary to form an opening for welding work in the piston 65.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the configuration in which the internal pressure cancellation plate is welded to the oil passage component member (oil passage configuration plate 40) fixed to the front cover has been described, but in the present invention, the inner pressure cancellation plate is fixed to the front cover. The internal pressure cancellation plate may be welded to a member other than the oil passage constituent member, or the internal pressure cancellation plate may be directly welded to the front cover member.

  Further, in the above-described embodiment, the cylindrical portion of the piston is provided with a communication hole that allows the inside of the case to communicate with the internal pressure cancellation chamber, and the area is reduced when the lockup clutch is released compared to when the lockup clutch is released. However, the place where the communication hole is provided is not limited to this. For example, a cylindrical portion is provided at the outer peripheral end of the internal pressure cancellation plate, and the communication hole is provided in the cylindrical portion. It is also possible to adopt a configuration.

  As described above, according to the present invention, when an internal pressure cancellation plate is provided to suppress fluctuations in the fastening force of the piston of the lockup clutch in accordance with fluctuations in the internal pressure of the torque converter, a decrease in strength or weight is reduced. Since it is possible to assemble the internal pressure cancel plate in a simple process and in a reliable support state while suppressing the increase, in the field of manufacturing technology of this type of torque converter or automatic transmission, or a vehicle equipped with the same, It may be suitably used.

DESCRIPTION OF SYMBOLS 1 Torque converter 2 Internal pressure chamber 4 Hydraulic chamber 6 Internal pressure cancellation chamber 10 Case 11 Front cover 40 Oil path structure plate 50 Internal pressure cancellation plate 60 Lock-up clutch 64 Piston 80 Communication hole LD Lock-up damper OWC One-way clutch T Torus

Claims (5)

A case having a front cover coupled to an output shaft of the engine; and a lock-up clutch housed in the case; and fastening of the lock-up clutch between the front cover and a piston of the lock-up clutch. A torque converter in which a hydraulic chamber to which hydraulic pressure is supplied is formed, and an internal pressure cancellation plate that forms an internal pressure cancellation chamber between the piston and the piston on the opposite side of the hydraulic chamber;
The internal pressure canceling plate is fixed to the front cover itself or to a member separate from the piston and fixed to the front cover by welding from the axial direction. Torque converter. The welded portion between the internal pressure cancellation plate and the front cover or the member fixed to the front cover is disposed radially inward from the inner peripheral edge of the piston. The torque converter according to 1. It said member which is fixed to the front cover, and wherein the oil path communicating with the hydraulic chamber is an oil path constituting member which is fixed to the front cover so as to form between the front cover The torque converter according to claim 1 or 2.   2. A communication hole is provided in which the inside of the case communicates with the internal pressure cancellation chamber, and the area is reduced when the lock-up clutch is engaged compared to when the lock-up clutch is released. The torque converter according to any one of claims 3 to 4. The piston is provided to be movable in the axial direction according to the magnitude of the fastening hydraulic pressure,
The piston includes a cylindrical portion extending in the axial direction,
The communication hole is formed at a position where an area of a portion of the cylindrical portion that is blocked by an outer peripheral end portion of the internal pressure canceling plate is larger when the lockup clutch is released than when the lockup clutch is released. The torque converter according to claim 4, wherein:

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