JP4604848B2 - Cooling mechanism when the rotary clutch is engaged - Google Patents

Description

  The present invention relates to an automatic transmission, and to a cooling mechanism when a rotary clutch is engaged.

  FIG. 4 shows a part of the structure of an automatic transmission provided with a rotary clutch mechanism having a centrifugal hydraulic balance mechanism. In this automatic transmission, a centrifugal hydraulic pressure balance chamber 4 is provided between an axially slidable piston 2 and a balance piston 3. When the control oil is introduced into the piston hydraulic chamber 5, the piston 2 moves to the balance piston 3 side to oppose the urging force of the return spring 11, and the plate 7a connected to the drum 1 is moved. The plate 7a and the friction plate 7b connected to the hub 9 constitute a rotation clutch C1. The hub 9 is also provided with a friction plate 12b that constitutes the brake B1 together with the plate 12a connected to the case 13.

  In the above configuration, when the drum 1 is connected to the hub 9, oil is introduced into the piston hydraulic chamber 5 while gradually disengaging the brake B1. As a result, the piston 2 moves and the rotary clutch C1 is engaged. At this time, the oil in the centrifugal hydraulic pressure balance chamber 4 is discharged to the input shaft 20 side. The following patent document 1 is mentioned as what discloses the same automatic transmission.

Here, since frictional heat is generated when the rotary clutch C1 is engaged, it is preferable to supply sufficient oil to cool the clutch. However, the structure shown in FIG. 4 does not particularly adopt a structure that actively supplies oil to the rotary clutch C1. Further, as described above, when the hub 9 is stopped, oil supply based on the centrifugal force caused by the rotation of the hub 9 cannot be expected.
JP-A-2-296072

  Therefore, the problem to be solved by the present invention is that sufficient oil is not supplied in the rotary clutch employed in the automatic transmission having the above-described configuration. Accordingly, an object of the present invention is to provide a cooling mechanism at the time of engagement of a rotary clutch that supplies oil and enables sufficient cooling of the rotary clutch in an automatic transmission provided with a centrifugal hydraulic balance chamber.

In the cooling mechanism at the time of engaging the rotary clutch based on the present invention, the rotary shaft, the drum provided on one end side of the rotary shaft, provided around the rotary shaft, and the axial direction of the rotary shaft. A piston is provided slidably, and a piston hydraulic chamber is formed between the drum and the drum.The piston is disposed opposite to the drum around the rotation shaft, and is fixed to the rotation shaft. On the opposite side of the drum, a balance piston disposed opposite to the piston around the rotating shaft so as to form a centrifugal hydraulic balance chamber between the piston and the piston, and the centrifugal hydraulic balance And an elastic member for biasing the piston toward the drum, one end abutting against the piston and the other end abutting against the balance piston. In the first state in which the piston is urged to the drum side of a member, the peripheral portion of the piston is without contact, is selected disengaged, the oil is introduced into the piston hydraulic chamber , against the biasing force of the elastic member, rotating said piston in a second state of being moved to the balance piston side, the peripheral edge of the piston contacts the engagement state is selected With a clutch.

Further, the piston is closed in the first state, and in the second state, oil for deriving the oil in the centrifugal hydraulic pressure balance chamber toward the rotary clutch provided outside. A cooling mechanism is provided in which a passage is opened , the drum has a drum convex region protruding in a direction opposite to the balance piston, and the piston has a piston convex region protruding in a direction opposite to the balance piston. A piston flange portion as a peripheral portion that projects outwardly from the side and abuts against the rotary clutch, and the outer surface of the side of the piston convex region is the inner surface of the side of the drum convex region In the first state, the inner surface of the side surface of the drum convex region is provided on the side portion of the piston convex region as the cooling mechanism. Closed in contact, and in the second state, is exposed from the side portion of the drum convex region, and leads out the oil in the centrifugal hydraulic pressure balance chamber toward the rotary clutch provided outside. A first through hole is formed in the piston flange portion, and an oil passage is formed in the piston flange portion to guide the oil in the centrifugal hydraulic pressure balance chamber that has passed through the through hole toward the rotary clutch. A second through hole is provided .

  According to the cooling mechanism when the rotary clutch is engaged based on the present invention, when the rotary clutch is engaged as the piston moves, oil in the centrifugal hydraulic pressure balance chamber is derived toward the rotary clutch as the piston moves. Since the configuration is adopted, the oil in the centrifugal hydraulic pressure balance chamber can be used as the cooling oil when the rotary clutch is engaged, the cooling is sufficiently performed when the rotary clutch is engaged, and the thermal degradation of the rotary clutch Can be prevented.

  A cooling mechanism at the time of engaging a rotary clutch in an embodiment based on the present invention will be described below with reference to FIGS. FIG. 1 is a partial cross-sectional view showing a part of an automatic transmission that employs a cooling mechanism at the time of engaging a rotary clutch in the embodiment, and FIG. 2 is a cooling mechanism at the time of engaging a rotary clutch in the embodiment. FIG. 3 is an overall perspective view of the piston employed in the cooling mechanism when the rotary clutch is engaged in the embodiment.

  First, referring to FIG. 1, in the automatic transmission according to the embodiment, a drum 1 is provided on one end side of an input shaft 20 as a rotating shaft housed in a case 13. The piston 2 is provided so as to be slidable along the axial direction of the input shaft 20, and the piston 2 is opposed to the drum 1 around the input shaft 20 so as to form the piston hydraulic chamber 5 between the input shaft 20 and the drum 1. Is provided. Further, it is fixed to the input shaft 20 and faces the piston 2 around the input shaft 20 so that a centrifugal hydraulic pressure balance chamber 4 is formed between the piston 2 and the piston 2 on the opposite side of the drum 1. Thus, a balance piston 3 is provided. Further, the centrifugal hydraulic balance chamber 4 has one end abutting against the piston 2 and the other end abutting against the balance piston 3, and a return spring (coil spring) as an elastic member for biasing the piston 2 toward the drum 1 side. 11 is provided at a plurality of locations so as to surround the input shaft 20.

  The drum 1 is provided in an annular shape so as to surround the input shaft 20, and protrudes from one end of the drum convex region 1 a and the drum side region 1 b, and outward from the drum side region 1 b toward the side. And a drum cylindrical region 1d extending parallel to the input shaft 20 from the drum flange region 1c.

  A plurality of plates 7 a are provided on the inner surface of the drum cylindrical region 1 d, and a friction material 7 b that engages with the plates 7 a is provided on the hub 9. The plate 7a and the friction material 7b constitute a rotary clutch C1. The hub 9 is provided with a plurality of friction materials 12b, and the case 13 is provided with a plurality of plates 12a. Brake B1 is comprised by the plate 12a and the friction material 12b.

  As shown in FIG. 3, the piston 2 is provided in an annular shape so as to surround the input shaft 20, and includes a piston convex region 2 a and a side region 2 b that protrude in a direction opposite to the balance piston 3, and this side portion. It has a piston flange portion 2c as a peripheral portion that projects outward from the region 2b toward the outside of the side and abuts against the rotary clutch C1. The outer surface of the side region 2b is provided so as to slide in contact with the inner surface of the drum side region 1b.

  Here, in the state of the piston 2 shown in FIG. 1, no oil is introduced into the piston hydraulic chamber 5, and the outer surface of the piston convex region 2 a is applied to the inner surface of the drum convex region 1 a based on the urging force of the return spring 11. The contact state is shown, and the piston flange portion 2c is not in contact with the rotation clutch C1, and shows a first state in which the rotation clutch C1 is in a non-engagement state. On the other hand, in the state of the piston 2 shown in FIG. 2, oil is introduced into the piston hydraulic chamber 5, the piston 2 moves to the balance piston 3 side opposite to the urging force of the return spring 11, and is rotated by the piston flange portion 2c. A second state in which the clutch C1 is engaged is shown.

  In the case where the first state and the second state are selected in the piston 2, the side region 2b of the piston convex region 2a has a drum side region of the drum convex region 1a in the first state. 1b is closed in contact with the inner surface, and in the second state, exposed from the drum side region 1b of the drum convex region 1a (the state shown in FIG. 2), the oil in the centrifugal hydraulic balance chamber 4 is removed from the rotary clutch. A plurality of first through holes 6 that form an oil passage for leading out toward C1 are provided on the circumference of the side region 2b. In the present embodiment, four points are provided on the circumference at a pitch of 90 degrees. In the first state, the first through hole 6 is closed on the inner surface of the drum side region 1b, but the oil in the centrifugal hydraulic balance chamber 4 does not leak from the first through hole 6 due to centrifugal force. In order to do so, the clearance between the inner surface of the drum side region 1b and the side region 2b of the piston convex region 2a is set. Note that the pressure leakage is set to be equal to or less than the force for urging the piston 2 by the return spring 11.

  Further, the piston flange portion 2c is provided with a second through hole 10 that forms an oil passage through which the oil in the centrifugal hydraulic balance chamber 4 that has passed through the through hole 6 is further led out toward the rotary clutch C1. A plurality of portions are provided on the circumference of the portion 2c. In the present embodiment, four points are provided on the circumference at a pitch of 90 degrees.

  As shown in FIG. 3, since the piston 2 is formed by stamping a steel plate, the second through hole 10 is punched so that the rib 10b of the steel plate remains in the second through hole 10. Yes. The first through hole 6 is formed by a post process using a drill or the like. Note that the first through hole 6 and the second through hole 10 are not formed on the same straight line passing through the center of rotation, but are preferably provided at shifted positions as shown in FIG. In FIG. 3, when the piston 2 rotates counterclockwise, the second through hole 10 is provided on the downstream side with respect to the rotation direction when viewed from the first through hole 6. As a result, the oil discharged from the first through hole 6 can smoothly flow into the second through hole 10. Further, the first through hole 6 does not open perpendicularly to the side region 2b, but is inclined with respect to the wall surface of the side region 2b so that the opening direction is directed to the direction in which the rotary clutch C1 is provided. It is open to do. Further, the rib 10b also guides the oil so as to lead out well toward the rotary clutch C1.

  According to the cooling mechanism at the time of engaging the rotary clutch in the present embodiment configured as described above, as shown in FIG. 2, in the second state in which the piston 2 is moved to the balance piston 3 side, the first through hole 6 is exposed from the drum side region 1b of the drum convex region 1a, and the oil in the centrifugal hydraulic pressure balance chamber 4 passes through the oil passage defined by the first through hole 6 and the second through hole 10 to rotate the clutch C1. Derived towards At this time, the engagement state of the rotary clutch C1 is selected by the balance piston 3. However, the oil in the centrifugal hydraulic pressure balance chamber 4 is supplied toward the rotary clutch C1, thereby the centrifugal hydraulic pressure balance chamber. The oil in 4 can be used as cooling oil, cooling is sufficiently performed when the rotary clutch C1 is engaged, preventing thermal deterioration and ensuring reliability. In particular, when the hub 9 is switched from the state locked by the brake B1, the oil lubrication due to the rotation of the hub 9 cannot be expected, so that the cooling mechanism of the present embodiment functions effectively. .

  In the present embodiment, the inclined portion 10a is formed inside the intersection of the drum convex region 1a and the drum side region 1b. As a result, the first through hole 6 is reliably exposed, and the space sandwiched between the outer surface of the piston 2 and the inner surface of the drum 1 is expanded, so that the oil flow led out from the first through hole 6 is reduced. It can be good.

  Further, as a cooling mechanism for opening the oil passage, the mechanism in which the through hole 6 of the piston 2 is opened and closed by the inner surface of the drum side region 1b has been described, but the first state and the second state of the piston 2 It is also possible to apply a mechanism for controlling the opening and closing of the through hole 6 (adoption of a door that opens and closes the through hole 6 using a link mechanism, adoption of a check ball) according to the movement between the two.

  In the cooling mechanism when the rotary clutch is engaged, the case where the input shaft is used as the rotary shaft has been described. However, in the automatic transmission provided with the centrifugal hydraulic pressure balance chamber, the rotary clutch mechanism provided with the centrifugal balance chamber by the balance piston. It is possible to apply the configuration of the invention of the present application as long as the location includes the combined device.

  Therefore, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a fragmentary sectional view which shows a part of automatic transmission by which the cooling mechanism at the time of rotation clutch engagement in embodiment based on this invention was employ | adopted. It is a schematic cross section which shows the cooling mechanism at the time of rotation clutch engagement in embodiment based on this invention. It is a whole perspective view of the piston employ | adopted as the cooling mechanism at the time of rotation clutch engagement in embodiment based on this invention. It is a fragmentary sectional view which shows a part of automatic transmission with which the cooling mechanism at the time of rotation clutch engagement was employ | adopted.

Explanation of symbols

  1 drum, 1a drum convex area, 1b drum side area, 1c drum flange area, 1d drum cylindrical area, 2 piston, 2a piston convex area, 2b side area, 2c piston flange area, 3 balance piston, 4 Centrifugal Hydraulic Balance Chamber, 5 Piston Hydraulic Chamber, 6 First Through Hole, 7a Plate, 7b Friction Material, 9 Hub, 10 Second Through Hole, 10b Rib, 11 Return Spring, 12a Plate, 12b Friction Material, 13 Case, 20 Input shaft, B1 brake, C1 rotary clutch.

Claims (1)

A rotation axis;
A drum provided on one end side of the rotating shaft and provided around the rotating shaft;
A piston that is slidable along the axial direction of the rotary shaft, and that is disposed opposite the drum around the rotary shaft so as to form a piston hydraulic chamber between the drum and the drum;
It is fixed to the rotating shaft and is opposed to the piston around the rotating shaft so that a centrifugal hydraulic pressure balance chamber is formed between the piston and the piston on the opposite side of the drum. A balanced piston,
An elastic member disposed in the centrifugal hydraulic balance chamber, one end abutting against the piston, the other end abutting against the balance piston, and urging the piston toward the drum;
In the first state in which the piston by the resilient member is biased to the drum side, the peripheral portion of the piston is without contact, is selected disengaged, the oil into the piston hydraulic chamber It is introduced, against the biasing force of the elastic member, wherein the piston, in a second state of being moved to said balance piston side, the peripheral edge of the piston abuts the engagement state is selected A rotating clutch
The piston is closed in the first state, and in the second state, the piston has an oil passage for leading the oil in the centrifugal hydraulic pressure balance chamber toward the rotary clutch provided outside. A cooling mechanism is provided ,
The drum has a drum convex region protruding in a direction opposite to the balance piston,
The piston has a piston convex region that protrudes in the opposite direction to the balance piston, and a piston flange portion as a peripheral portion that projects outwardly from the side and abuts against the rotary clutch,
The outer surface of the side of the piston convex region is provided to slide in contact with the inner surface of the side of the drum convex region,
As the cooling mechanism,
The side of the piston convex region is closed in contact with the inner surface of the side of the drum convex region in the first state, and the side of the drum convex region in the second state. A first through hole that is exposed from a side portion and that forms an oil passage for guiding the oil in the centrifugal hydraulic pressure balance chamber toward the rotary clutch provided outside;
Wherein the piston flange, the oil of the centrifugal hydraulic balance chamber that has passed through the through hole, Ru second through hole is provided to form an oil passage for leading toward the rotating clutch,
Cooling mechanism when the rotary clutch is engaged.

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