JP2007303483A - Bonded piston seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bonded piston seal without reducing sealability, by eliminating tearing-off in installation by a volume shortage of a seal member, when sealing an inner peripheral part of a cancel plate, by efficiently canceling centrifugal hydraulic pressure on the pressurizing chamber side, by increasing the centrifugal hydraulic pressure of a balancing oil chamber by sealing the inner peripheral part of the cancel plate. <P>SOLUTION: An outer peripheral seal part 32 sliding with an outer peripheral cylindrical part 22 of a piston member 20, is installed in an outer peripheral end part 31 of the cancel plate 30. An inner peripheral seal part 38 sliding in an inner peripheral cylindrical part 13 of a cylinder 10, is installed over an inner peripheral end part 37 from an inner peripheral cylindrical part 36 of a projection part 35 formed in a central part 33 of the cancel palate 30, to seal the balancing oil chamber N defined by the cylinder 10, the piston member 20 and the cancel plate 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bonded piston seal (BPS) used for clutch engagement in an automatic transmission of an automobile. More specifically, the present invention relates to the structure of a sealing device provided on a BPS cancel plate.

  In a BPS used for clutch engagement in automatic transmissions such as AT and CVT for automobiles, a cancel plate is provided for the purpose of canceling a centrifugal hydraulic load on the piston member.

  As shown in FIG. 5, the BPS 100 used in the prior art is a piston that forms a pressurizing chamber M with the cylinder 101, which is slidably in close contact with the inside of the cylinder 101 having a substantially U-shape and having a bottomed cylindrical shape. The pressure plate M is pressurized with the member 111, the cancel plate 121 that faces the bottom 102 of the cylinder 101 with the piston member 111 interposed therebetween, and that defines the balanced oil chamber N with the piston member 111 and the cylinder 101. And a return spring 131 that functions to push back the piston member 111 pushed down.

  The cancel plate 121 is formed by punching a metal plate such as a steel plate, and its outer peripheral portion 122 protrudes toward the balanced oil chamber N and is slidable on the inner peripheral surface of the outer peripheral cylindrical portion 112 of the piston member 111. It is sealed by an outer peripheral seal portion 123 that is attached so as to be in close contact with the outer periphery. The inner peripheral portion 124 is supported by a snap ring 132 fitted in a mounting groove 104 formed on the outer peripheral surface of the inner peripheral cylindrical portion 103 of the cylinder 101, and a piston member 111 is disposed on the end portion of the piston member 111. An oil discharge hole 125 for discharging oil from the balanced oil chamber N when the capacity of the pressurizing chamber M decreases by moving to the side is provided. That is, since the inner peripheral portion 124 of the cancel plate 121 is not sealed, the centrifugal oil pressure generation starting point diameter X1 of the balanced oil chamber N becomes the inner peripheral side end face 126 or the oil discharge portion 125 of the canceller plate 121, and The centrifugal oil pressure in the balanced oil chamber N is smaller than that in the centrifugal oil pressure, and the centrifugal oil pressure in the pressurizing chamber M cannot be efficiently canceled when the engagement of the clutch is cut off.

  Further, in Patent Document 1 below, a rubber that seals the fitting surface between the cancel plate and the inner peripheral cylindrical portion of the housing on the inner peripheral portion of the canceller plate in order to shorten the axial dimension and reduce the size of the clutch device. It is disclosed to attach a sealing member of a cylindrical elastic body. However, if the seal member is partially attached to the inner peripheral end of the canceller plate, there is a problem that the sealing performance is deteriorated due to the lumps of the rubber when assembled due to the small volume of the seal member.

Japanese Patent Laid-Open No. 2004-060750

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to seal the inner periphery of the cancel plate to increase the centrifugal hydraulic pressure of the balanced oil chamber, It is possible to efficiently cancel the centrifugal hydraulic pressure of the cylinder, and when the inner periphery of the cancel plate is sealed, there is no stuffiness at the time of assembly due to insufficient volume of the seal member, and the sealing performance does not deteriorate. It is to provide a piston seal.

  In order to achieve the above object, a bonded piston seal according to claim 1 of the present invention is an axially slidable close contact with the inside of a bottomed cylindrical cylinder having a substantially U shape, and is added by the cylinder. Cancellation having a piston member defining a pressure chamber, and a convex portion on the inner peripheral side of the central portion that defines the balanced oil chamber with the piston member and the cylinder facing the bottom of the cylinder across the piston member In a bondet piston seal comprising a plate and a return spring that functions to push back the piston member pushed down when the pressurizing chamber is pressurized, the piston member is disposed at an outer peripheral end of the cancel plate. An outer peripheral seal portion that slides on the outer peripheral cylindrical portion of the cylinder is attached, and the inner periphery of the cylinder extends from the inner peripheral cylindrical portion that forms the convex portion to the inner peripheral end portion. And clamped by the inner peripheral seal portion to slide parts, is characterized in that it has sealing the balancing oil chamber.

  The present invention has the following effects.

  In other words, the bonded canceller seal according to claim 1 of the present invention having the above-described configuration is provided with an outer peripheral seal portion that is in sliding contact with an outer peripheral cylindrical portion of the piston member at an outer peripheral end portion of the cancel plate, and an inner peripheral end portion. Since the inner peripheral seal portion slidably contacting the inner peripheral cylinder portion of the cylinder is attached to the inner peripheral end portion of the cancel plate and the outer peripheral surface of the inner peripheral cylinder portion of the cylinder, the balanced oil chamber is sealed. Therefore, it is possible to increase the centrifugal hydraulic pressure in the balanced oil chamber, and to efficiently cancel the centrifugal hydraulic pressure in the pressurizing chamber when the clutch is disengaged.

  Further, since the inner peripheral seal portion is installed from the inner peripheral cylindrical portion of the convex portion formed on the inner peripheral side of the central portion of the cancel plate to the inner peripheral end portion, the volume of the seal member Is ensured and no mess is produced during assembly, and deterioration of the sealing performance can be prevented.

  Exemplary embodiments of the present invention will be described below with reference to the drawings.

  1 is a schematic cross-sectional view of a BPS according to the present invention, and FIG. 2 is an enlarged cross-sectional view of an inner peripheral seal portion provided on a cancel plate in FIG.

  A BPS 1 according to the present invention shown in FIG. 1 includes a piston member 20 that forms a pressurizing chamber M with a cylinder 10 that is slidably brought into close contact with the inside of a cylinder 10 having a substantially U-shape and having a bottomed cylindrical shape. And a cancel plate 30 that has a convex portion 35 on the inner peripheral side of the central portion that defines the balanced oil chamber N with the piston member 20 and the cylinder 10, facing the bottom portion 11 of the cylinder 10 across the piston member 20, A return spring 40 that functions to push back the piston member 20 that has been pushed down when the pressurizing chamber M is pressurized is provided.

  The cylinder 10 is a bottomed cylindrical shape having a substantially U-shape that is attached to a drive shaft (not shown), and one end of the cylinder 10 extends in the axial direction from the other end of the bottom portion 11 coupled to the outer peripheral cylindrical portion 12. In the peripheral cylinder portion 13, a mounting groove 14 for fitting the snap ring 41, an oil supply port 15 for introducing the working oil into the pressurizing chamber M, and an oil for introducing the working oil into the balanced oil chamber N A supply port 16 and a discharge port 17 for discharging the hydraulic oil in the equilibrium chamber N are opened.

  The piston member 20 is configured such that an end 24 opposite to the end connected to the bottom 21 of the outer cylinder 22 extending in the axial direction from the inner cylinder 23 presses the multi-plate clutch 42. The pressurizing chamber M is defined by the bottom 21, the outer peripheral cylindrical portion 12 of the cylinder 10, the bottom 11, and the inner peripheral cylindrical portion 13.

  The cancel plate 30 is obtained by simply press-drawing a metal plate such as a steel plate, and the outer peripheral seal portion 32 of a rubber-like elastic body that is in sliding contact with the inner peripheral surface of the outer peripheral cylindrical portion 22 of the piston member 20 at the outer peripheral end portion 31. And the piston member 20 is moved to the bottom 11 side (the upper side in the figure) of the cylinder 10 by the urging force when the hydraulic pressure in the pressurizing chamber M is released. The return spring 40 is seated, and the inner peripheral cylindrical portion of the cylinder 10 extends from the inner peripheral cylindrical portion 36 to the inner peripheral end portion 37 of the convex portion 35 formed in the central portion 33 on the inner peripheral side from the flat portion 34. A rubber-like elastic inner peripheral seal portion 38 that slides on the outer peripheral surface 13 is attached.

  A surface opposite to the axial direction of the inner peripheral end portion 37 on which the inner peripheral seal portion 38 is attached is a receiving surface 39 that contacts the nap ring 41 so that the axial movement of the cancel plate 30 is restricted. Yes. The receiving surface 39 is provided with a step 39c so that the outer peripheral side receiving surface 39a comes into contact with the snap ring 41, and the tip end portion 38a of the inner peripheral seal portion 38 is wrapped around and attached only to the inner peripheral side receiving surface 39b. It has become. Moreover, since the step 39c has a predetermined height h1, the step 39c is higher than the height h2 of the tip end portion 38a attached around the inner peripheral receiving surface 39b. That is, a gap k is formed between the outer peripheral side receiving surface 39a and the top of the tip end portion 38a attached to the inner peripheral side receiving surface 39b, and even if the outer peripheral side receiving surface 39a contacts the snap ring 41, The tip end portion 38 a of the inner peripheral seal portion 38 attached to the inner peripheral receiving surface 39 b is not in contact with the snap ring 41.

  Therefore, in the above configuration, since the outer peripheral seal portion 32 is attached to the outer peripheral end portion 31 of the cancel plate 30 and the inner peripheral seal portion 38 is attached to the inner peripheral end portion 37, the bottom portion of the piston member 20 21, the outer peripheral cylindrical portion 22, the inner peripheral cylindrical portion 13 of the cylinder 10, and the balanced oil chamber N defined by the cancel plate 30 can be sealed, and the centrifugal hydraulic pressure generation starting diameter X2 is the inner peripheral cylinder of the cylinder 10. Since it becomes the inner peripheral end face 13a of the portion 13 and the centrifugal hydraulic pressure can be increased, the centrifugal hydraulic pressure in the pressurizing chamber M can be efficiently canceled when the engagement of the clutch is shut off.

  In FIG. 4, as compared with the conventional example, each part where the balanced oil chamber is plotted on the X axis from the outer peripheral side to the inner peripheral side at a constant interval and the centrifugal oil pressure at each part is indexed on the Y axis. As shown in this result, the starting point of the centrifugal oil pressure is reduced by the amount of the measurement site extending in the inner circumferential direction of the X axis (the length of the X axis is long), and the centrifugal oil pressure at the same measurement site is increased. ing. Therefore, it can be understood that the canceling power is improved by the difference R.

  Further, since the inner peripheral seal portion 38 is installed from the inner peripheral cylindrical portion 36 to the inner peripheral end portion 37 of the convex portion 35 formed in the central portion 33 of the cancel plate 30, a rubber volume is secured. As a result, there is no stuffiness of rubber at the time of assembly, and it becomes possible to prevent a decrease in sealing performance. Furthermore, since the tip end portion 38 a of the inner peripheral seal portion 38 is only attached to the inner peripheral side receiving surface 39 a of the inner peripheral end portion 37 of the cancel plate 30, the outer peripheral side receiving surface 39 a of the cancel plate 30 is attached to the snap ring 41. Even if it comes into contact, the tip end portion 38a of the inner peripheral seal portion 38 does not come into contact with the snap ring 41, and it becomes possible to prevent the deterioration of the sealing performance due to rubber burrs and the generation of foreign matters due to lashes.

  FIG. 3 is another embodiment of the present invention. The inner peripheral seal portion 38 in the present embodiment is formed so as to thinly cover the inner peripheral cylindrical portion 36 of the convex portion 35 formed on the cancel plate 30 and to cover the inner peripheral end portion 37 thickly. The rubber volume of the circumferential seal portion 38 is secured.

Partial sectional view of BPS according to the present invention FIG. 1 is an enlarged cross-sectional view of the inner seal portion The expanded sectional view of the inner peripheral seal part concerning another example of the present invention. Comparison explanatory diagram of centrifugal oil pressure in balanced oil chamber Partial sectional view of BPS according to conventional example

Explanation of symbols

1 Bonded piston seal (BPS)
DESCRIPTION OF SYMBOLS 10 Cylinder 11,21 Bottom part 12,22 Outer cylinder part 13,23,36 Inner circumference cylinder part 14 Mounting groove 15,16 Oil supply port 17 Oil discharge port 20 Piston member 30 Cancel plate 31, 37 End part 32,38 Seal part 33 Central part 34 Flat part 35 Convex part 39, 39a, 39b Receiving surface 40 Return spring 41 Snap ring 42 Multi-plate clutch M Pressurizing chamber N Balanced oil chamber

Claims (1)

A piston member that forms a pressurizing chamber with the cylinder in close contact with the inside of the cylindrical cylinder with a bottom having a substantially U-shape so as to be slidable in the axial direction, and faces the bottom of the cylinder with the piston member interposed therebetween The piston member and the cylinder define a balanced oil chamber, the cancel plate having a convex portion on the inner peripheral side of the central portion, and the piston member pushed down by the pressurizing chamber being pressed back. Bonded piston seal with a return spring that functions like
An outer peripheral seal portion that slides on the outer peripheral cylindrical portion of the piston member is attached to the outer peripheral end portion of the cancel plate, and the inner peripheral cylindrical portion that forms the convex portion extends from the inner peripheral cylindrical portion to the inner peripheral end portion. A bonded piston piston seal characterized in that an inner peripheral seal portion that slides on an inner peripheral cylindrical portion is attached to seal the balanced oil chamber.

Images