JP2008309292A - Snap ring of hydraulic friction engagement device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a snap ring of a vehicular hydraulic frictional engaging device for suitably preventing slipping-out from a groove by a simple constitution. <P>SOLUTION: This snap ring is composed of a first snap ring 64 formed so that a thickness dimension gradually increases in the outer peripheral direction and arranged on the piston 52 side, and a second snap ring 66 formed so that a thickness dimension gradually reduces in the outer peripheral direction and arranged on the flange 48 side, and is used by being arranged so that a piston 52 side plane part 64a in its first snap ring 64 and a flange 48 side plane part 66a in the second snap ring 66 become substantially parallel when superposing the first snap ring 64 and the second snap ring 66. Thus, the slipping-out to the inside of the snap ring 50 can be restrained by the complementary wedge effect without applying special processing to a housing 26. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hydraulic friction engagement device for a vehicle, for restricting movement of an engagement element included in the hydraulic friction engagement device in an axial direction in a hydraulic friction engagement device provided in a vehicle. The present invention relates to a snap ring, and more particularly to an improvement for preventing the snap ring from coming off from a groove due to shrinking inward.

  In a hydraulic friction engagement device provided in an automatic transmission or the like of a vehicle, a snap ring for restricting movement of an engagement element included in the hydraulic friction engagement device in an axial direction is used in various vehicles. ing. For example, this is the hydraulic brake structure of an automatic transmission described in Patent Document 1. In this technology, a snap ring that restricts the movement of the multi-plate brake and the movement of the spring retainer that supports one end of the spring in the vicinity of both axial ends of the multi-plate brake provided in the housing of the automatic transmission. A configuration in which is provided is proposed.

JP-A-9-89015

  By the way, in the conventional configuration as described above, for example, a problem has been reported in which a force for winding the snap ring is generated by a rotational torque generated when the engagement element is engaged, and the snap ring is contracted inward to be removed from the groove. It was. In order to solve such a problem, it is conceivable to form the groove in a tapered shape, but it is difficult to process and is not suitable for practical use. Further, it is conceivable to separately arrange a plate with protrusions for preventing disengagement from the groove, but this causes a new problem that the number of parts increases and the weight increases. For this reason, development of the snap ring of the hydraulic friction engagement device for vehicles which prevents the slipping off from the groove with a simple configuration has been demanded.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a snap ring for a hydraulic friction engagement device for a vehicle that can be suitably prevented from coming off from a groove with a simple configuration. There is to do.

  In order to achieve such an object, the gist of the present invention is that a hydraulic friction engagement device provided in a vehicle moves in an axial direction of an engagement element included in the hydraulic friction engagement device. 1 is a snap ring of a hydraulic friction engagement device for a vehicle for regulating the pressure, and is formed so that a thickness dimension gradually increases toward an outer peripheral direction, and is disposed on the pressing member side. The second snap ring is formed so that the thickness dimension gradually decreases toward the outer peripheral direction and is disposed on the support member side, and the first snap ring and the second snap ring are overlapped with each other. Sometimes, the first snap ring is disposed and used so that the flat surface portion on the pressing member side and the flat surface portion on the support member side in the second snap ring are substantially parallel to each other. Also It is.

  If it does in this way, it forms so that a thickness dimension may increase gradually toward an outer peripheral direction, and it forms so that a thickness dimension may decrease gradually toward the 1st snap ring arrange | positioned at the press member side, and an outer peripheral direction. And a second snap ring disposed on the support member side, and when the first snap ring and the second snap ring are overlapped, the first snap ring has the pressing member side. Since the flat surface portion of the second snap ring and the flat surface portion on the support member side of the second snap ring are disposed so as to be substantially parallel to each other, the housing is not complementary and is not complementary. The rust effect can suppress the snap ring from coming off. That is, it is possible to provide a snap ring for a hydraulic friction engagement device for a vehicle that can be suitably prevented from coming off the groove with a simple configuration.

  Here, it is preferable that the friction coefficient between the flat surface portion on the support member side in the second snap ring and the contact surface between the flat surface portion in the annular groove to which the second snap ring is fitted is The friction coefficient between the contact surfaces when the first snap ring and the second snap ring are overlapped is smaller. In this way, the complementary wedge effect of the first snap ring and the second snap ring can be exerted more remarkably, and the inward release can be more suitably suppressed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram of an automatic transmission 10 for a vehicle to which the present invention is preferably applied. This automatic transmission 10 is used, for example, mounted in the left-right direction (sideways) on an FF vehicle, and is a single pinion type in a housing (transmission case) 26 as a non-rotating member attached to a vehicle body. The first planetary gear unit 12 is mainly composed of a first transmission 14, a double pinion type second planetary gear unit 16 and a single pinion type third planetary gear unit 18 are mainly composed of a Ravigneaux type. The second transmission unit 20 is provided on a common axis C, and the rotation of the input shaft 22 is shifted and output from the output gear 24. The input shaft 22 is a turbine shaft of a torque converter 32 as a fluid power transmission device that is rotationally driven by an engine 30 as a driving force source for traveling.

  The engine 30 is, for example, an internal combustion engine such as a gasoline engine that generates a driving force by combustion of fuel injected in a cylinder. The torque converter 32 includes a pump impeller 34 connected to the crankshaft of the engine 30, a turbine impeller 36 connected to the input shaft 22 of the automatic transmission 10, and a one-way clutch. A stator impeller 38 that is prevented from rotating in one direction with respect to the housing 26 of the machine 10, and transmits power between the pump impeller 34 and the turbine impeller 36 via a fluid. A lock-up clutch 40 is provided between the pump impeller 34 and the turbine impeller 36 for connecting them directly.

  The output gear 24 is meshed with a differential drive pinion that meshes with a differential ring gear to form a final gear pair and meshes with a counter driven gear that is coaxially arranged to transmit power to a differential gear device (not shown). It is a counter drive gear which comprises. In the automatic transmission 10 configured as described above, the output of the engine 30 is transmitted to a pair of drive wheels via the torque converter 32, the automatic transmission 10, the differential gear device, a pair of axles, and the like. The automatic transmission 10 and the torque converter 32 are substantially symmetrical with respect to the center line (axial center) C, and the lower half of the center line C is omitted in the skeleton diagram of FIG. .

  FIG. 2 is an operation table for explaining the operation state of the engagement element when a plurality of shift stages (gear stages) are established in the automatic transmission 10, where “◯” indicates engagement and “◎” indicates engine brake. Only the time represents engagement. The automatic transmission 10 is a hydraulic type whose engagement is controlled by a hydraulic actuator, such as a multi-plate clutch or brake, as an engagement element for selectively establishing a plurality of shift speeds according to the running state of the vehicle. The first clutch C1, the second clutch C2 (hereinafter simply referred to as the clutch C unless otherwise specified), the first brake B1, the second brake B2, and the third brake B3 (hereinafter particularly distinguished as friction engagement devices). If not, it is simply called Brake B). In the automatic transmission 10, the clutch C and the brake B are controlled by controlling the hydraulic pressure supplied from the hydraulic control circuit by excitation / de-excitation or current control of an electromagnetic control valve provided in a hydraulic control circuit (not shown). The respective engagement states are switched, and one of a plurality of shift stages is selectively established in the automatic transmission 10 in accordance with the combination of engagement and release of the clutch C and the brake B.

  That is, as shown in FIG. 2, the automatic transmission 10 includes the rotating elements (sun gears S1 to S3, carriers CA1 to CA3, ring gears R1 to R3) of the first transmission unit 14 and the second transmission unit 20. The six forward gears from the first speed gear stage “1st” to the sixth speed gear stage “6th” are established, and the reverse gear stage “R” is established according to the combination of any of the connected states. . For example, in the forward gear stage, the first speed gear stage is set by engagement of the first clutch C1 and the second brake B2, and the second speed gear stage is set by the engagement of the first clutch C1 and the first brake B1. The engagement of C1 and the third brake B3 results in the third speed gear, the engagement of the first clutch C1 and the second clutch C2, the fourth speed gear, the engagement of the second clutch C2 and the third brake B3. The fifth speed gear stage is established by the engagement of the second clutch C2 and the first brake B1, respectively. Further, the reverse gear stage is established by engagement of the second brake B2 and the third brake B3, and the neutral state is established when both the clutch C and the brake B are released. In addition, since the one-way clutch F1 is provided in parallel to the second brake B2 that establishes the first speed gear stage “1st”, only the first clutch C1 is engaged when starting (acceleration) When the engine brake is applied, the first clutch C1 and the second brake B2 are engaged. The gear ratio (transmission ratio) γ of each gear stage (= the rotational speed of the input shaft 22 / the rotational speed of the output gear 24) is determined by the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear. Each gear ratio of the gear unit 18 (= the number of teeth of the sun gear / the number of teeth of the ring gear) is appropriately determined according to ρ1, ρ2, and ρ3. As described above, the automatic transmission 10 according to this embodiment establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of hydraulic friction engagement devices, that is, the clutch C and the brake B. As is apparent from the operation table of FIG. 2, the gears can be switched by so-called clutch-to-clutch shifting in which any two of the clutch C and the brake B are gripped.

  FIG. 3 is a partial cross-sectional view illustrating in detail the configuration of the first brake B1 as a hydraulic friction engagement device provided in the automatic transmission 10. As shown in FIG. As shown in FIG. 3, the automatic transmission 10 is provided as an element of the first brake B1 on the inner peripheral surface of a bottomed cylindrical portion 42 formed on the inner peripheral side of the housing 26 and having one open side. , A plurality of (four in FIG. 3) separator plates 44a, 44b, 44c, 44d (hereinafter simply referred to as separator plates 44 unless otherwise specified) as first engaging elements, and a second engagement The separator plate 44 between the piston 52 and a plurality of (four in FIG. 3) friction plates 46 a, 46 b, 46 c, 46 d (hereinafter simply referred to as the friction plate 46 unless otherwise specified) as elements. A flange 48 as a support member for pressing the friction plate 46, and for restricting the movement of the flange 48 in the axial direction (toward the opening side of the bottomed cylindrical portion 42) A piston 52 as a pressing member for pressing the separator plate 44 and the friction plate 46 between the snap ring 50 according to an embodiment of the present invention and the flange 48, and the piston 52 against the flange 48. And a spring 54 that biases the first brake B1 toward the side for releasing the first brake B1.

  Longitudinal spline teeth are formed in the axial direction on the inner peripheral surface of the bottomed cylindrical portion 42. In addition, a plurality of protrusions that can be fitted to the spline teeth of the bottomed cylindrical portion 42 are formed on the outer peripheral side of each of the plurality of separator plates 44. The bottom cylindrical portion 42 is spline-fitted so as to be movable in the axial direction and not relatively rotatable. Further, on the outer peripheral side of the hub 56 configured to rotate integrally with the carrier CA1 of the first planetary gear device 12, longitudinal spline teeth are formed in the axial direction. A plurality of protrusions that can be fitted to the spline teeth of the hub 56 are formed on the inner peripheral side of each of the plurality of friction plates 46, and the plurality of friction plates 46 are arranged on the outer periphery of the hub 56. It is spline-fitted to the side so as to be movable in the axial direction and not to be relatively rotatable. Further, as shown in FIG. 3, the plurality of separator plates 44 and the friction plates 46 are arranged alternately with respect to the axial direction.

  A plurality of protrusions that can be fitted to the spline teeth of the bottomed cylindrical portion 42 are formed on the outer peripheral side of the flange 48, and the flange 48 has the plurality of projections in the bottomed cylindrical portion 42. On the opening side of the separator plate 44 and the friction plate 46, the bottomed cylindrical portion 42 is spline-fitted so as to be movable in the axial direction and not relatively rotatable. The snap ring 50 is fitted in an annular groove 58 formed in the inner peripheral surface of the bottomed cylindrical portion 42 so as not to move in the axial direction, and is splined to the bottomed cylindrical portion 42. Movement of the fitted flange 48, the plurality of separator plates 44, and the friction plate 46 toward the opening side in the axial direction is restricted.

  The spring 54 is interposed between the flange 48 and the piston 52, and urges the piston 52 toward the bottom of the bottomed cylindrical portion 42 with respect to the flange 48. Further, an oil seal 60 is provided between the bottomed cylindrical portion 42 and the piston 52 to provide oil tightness, and oil formed between the bottomed cylindrical portion 42 and the piston 52 is provided. The dense space functions as an oil chamber 62 that generates a propulsive force that moves the piston 52 by hydraulic pressure.

  In the first brake B1 configured as described above, when the hydraulic oil is supplied to the oil chamber 62 from a hydraulic oil supply passage (not shown), the piston 52 opens in the axial direction of the bottomed cylindrical portion 42. The plurality of separator plates 44 and the friction plate 46 are clamped between the piston 52 and the flange 48, and the relative rotation is impossible due to friction. One brake B1 is engaged. When the hydraulic oil is discharged from the oil chamber 62, the piston 52 moves toward the bottom side in the axial direction of the bottomed cylindrical portion 42 (the side opposite to the flange 48) by the biasing force of the spring 54. The first brake B1 is released by releasing the plurality of separator plates 44 and the friction plates 46 that have been moved and clamped between the piston 52 and the flange 48 and allowing the relative rotation thereof. Be made. In this way, the engagement state of the first brake B1 is controlled by controlling the hydraulic pressure supplied to the oil chamber 62 from a hydraulic control circuit (not shown).

  FIG. 4 is a perspective view illustrating the configuration of the snap ring 50 in detail. As shown in FIG. 4, the snap ring 50 of this embodiment includes two snap rings having different shapes, that is, a first snap ring 64 formed so that the thickness dimension gradually increases toward the outer periphery, The second snap ring 66 is formed so that the thickness dimension gradually decreases in the direction. The first snap ring 64 and the second snap ring 66 are both formed in a partial annular shape by SPCC (cold rolled steel plate) or the like, and are bent in a direction in which the diameter decreases ( By being disposed in the annular groove 58 in a contracted state, it is fitted into the annular groove 58 by an elastic force in the direction of increasing the diameter. Note that the first snap ring 64 and the second snap ring 66 may be made of the same material or may be made of different materials. Furthermore, the radial dimension before being fitted into the annular groove 58 (the state shown in FIG. 4 or 5) may be different. As shown in FIG. 3, in the annular groove 58 formed on the inner peripheral surface of the bottomed cylindrical portion 42, the first snap ring 64 is on the bottom side of the bottomed cylindrical portion 42, that is, on the piston 52 side. In addition, the second snap ring 66 is disposed on the opening side of the bottomed cylindrical portion 42, that is, on the flange 48 side.

  FIG. 5 is a perspective view showing a state in which the first snap ring 64 and the second snap ring 66 are overlapped. As shown in FIG. 5, when the first snap ring 64 and the second snap ring 66 are overlapped with each other, the abutting surfaces of the first snap ring 64 (which are opposed to each other). The flat surface portion 64a on the side different from the contact surface 64b and the flat surface portion 66a on the second snap ring 66 on the side different from the contact surface 66b are substantially parallel to each other. Yes. As shown in FIG. 3, the snap ring 50 is configured such that the flat portion 64a of the first snap ring 64 is on the piston 52 side and the flat portion 66a of the second snap ring 66 is on the flange 48 side. In other words, the snap ring 50 is used when the first snap ring 64 and the second snap ring 66 are overlapped with each other. The flat surface portion 64a on the piston 52 side and the flat surface portion 66a on the flange 48 side of the second snap ring 66 are disposed and used so as to be substantially parallel to each other.

  In the snap ring 50, preferably, the friction coefficient k1 between the flat portion 66a on the flange 48 side of the second snap ring 66 and the contact surface 58a of the flat portion 66a of the annular groove 58 is The friction coefficient k2 between the contact surfaces 64b and 66b when the first snap ring 64 and the second snap ring 66 are overlapped is smaller. That is, the relationship k1 <k2 is established. For this reason, preferably, at least one of the contact surfaces 64b and 66b when the first snap ring 64 and the second snap ring 66 are overlapped is processed so that the friction coefficient is reduced by polishing or the like. Has been. Alternatively, the friction coefficient of at least one of the contact surface 58a of the flat portion 66a on the flange 48 side of the second snap ring 66 and the flat portion 66a of the annular groove 58 is increased by roughing or the like. Has been processed.

  In the snap ring 50 configured as described above, when fitted into the annular groove 58, the second snap ring 66 is interposed between the annular groove 58 and the first snap ring 64 like a so-called wedge. Be made. Here, for example, when considering a case where the first snap ring 64 contracts inward, that is, in a direction in which the diameter decreases, due to friction with the flange 48, the first snap ring 66 in the first snap ring 66 has its first The taper structure of the contact surface 66b with the snap ring 64 can suppress the first snap ring 64 from shrinking inward. In addition, the friction coefficient k1 between the flat portion 66a on the flange 48 side of the second snap ring 66 and the contact surface 58a of the annular groove 58 with the flat portion 66a is determined by the first snap ring 64 and the first snap ring 64. Slip of the second snap ring 66 with respect to the annular groove 58 is suppressed by being smaller than the friction coefficient k2 between the contact surfaces 64b and 66b when the two snap rings 66 are overlapped. Thus, the first snap ring 64 and the snap ring 50 can be further preferably prevented from coming out of the annular groove 58. In particular, in the structure in which the urging force of the return spring always acts on the snap ring as in the first brake B1, a force for winding the snap ring is generated by the rotational torque generated when the engaging element is engaged, and the snap ring is contracted inward. In this case, the snap ring does not return to the original due to friction with the flange, and as a result, there is a possibility that the snap ring may come off. However, according to the snap ring 50 as in the present embodiment, the first snap ring 64 and It is possible to suitably prevent the second snap ring 66 from coming off the annular groove 58 due to the complementary wedge effect.

  Thus, according to the present embodiment, the first snap ring 64 formed on the piston 52 side that is the pressing member is formed so that the thickness dimension gradually increases toward the outer circumferential direction, and the outer circumferential direction. The first snap ring 64 and the second snap ring 66 are formed such that the thickness dimension gradually decreases toward the flange 48 as the support member. When overlapped, the flat portion 64a on the piston 52 side of the first snap ring 64 and the flat portion 66a on the flange 48 side of the second snap ring 66 are arranged so as to be substantially parallel. Since it is used, it is possible to prevent the snap ring 50 from coming off due to a complementary wedge effect without special processing of the housing 26.That is, it is possible to provide the snap ring 50 of the hydraulic friction engagement device for a vehicle that can be suitably prevented from coming off from the annular groove 58 with a simple configuration.

  The friction coefficient k1 between the flat surface portion 66a on the flange 48 side of the second snap ring 66 and the contact surface 58a of the flat surface portion 66a of the annular groove 58 in which the second snap ring 66 is fitted is Since the friction coefficient k2 between the contact surfaces 64a and 66a when the first snap ring 64 and the second snap ring 66 are overlapped is smaller, the first snap ring 64 and the second snap ring 64 The complementary wedge effect of the snap ring 66 can be made more remarkable, and the inward release can be more suitably suppressed.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the snap ring of the present invention is applied to the first brake B1 which is a hydraulic friction engagement device in which the spring 54 is interposed between the flange 48 as the support member and the piston 52 as the pressing member. However, the present invention is not limited to this, and the present invention is preferably applied to a brake in which the spring 54 is not provided between the flange 48 and the piston 52. . Needless to say, the hydraulic friction engagement device to which the present invention is applied need not be a brake, and can also be suitably applied to a clutch.

  In the above-described embodiment, the first snap ring 64 and the second snap ring 66 are formed of SPCC (cold rolled steel plate). It may be formed by being deformed into a partial annular shape. That is, the manufacturing method is not limited as long as it can provide a complementary wedge effect when fitted in the annular groove 58.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

1 is a skeleton diagram of an automatic transmission for a vehicle to which the present invention is preferably applied. FIG. 2 is an operation table for explaining operation states of engagement elements when a plurality of shift speeds are established in the automatic transmission of FIG. 1. FIG. 2 is a partial cross-sectional view illustrating in detail a configuration of a first brake as a hydraulic friction engagement device provided in the automatic transmission of FIG. 1. It is a perspective view explaining in detail the structure of the snap ring which is one Example of this invention. FIG. 5 is a perspective view showing a state in which the snap rings of FIG. 4 are superposed on each other.

Explanation of symbols

44: Separator plate (engaging element)
46: Friction plate (engagement element)
48: Flange (support member)
50: Snap ring 52: Piston (pressing member)
58: annular groove 58a: contact surface 64: first snap ring 64a: flat surface (pressing member side)
64b: abutment surface 66: second snap ring 66a: flat surface (support member side)
66b: Contact surface B1: First brake (hydraulic friction engagement device)

Claims (2)

In a hydraulic friction engagement device provided in a vehicle, a snap ring of a vehicle hydraulic friction engagement device for restricting movement of an engagement element included in the hydraulic friction engagement device in an axial direction. And
A first snap ring formed so that the thickness dimension gradually increases toward the outer peripheral direction and disposed on the pressing member side;
A second snap ring which is formed so that the thickness dimension gradually decreases toward the outer peripheral direction and is disposed on the support member side;
When the first snap ring and the second snap ring are overlapped, the flat surface portion on the pressing member side of the first snap ring and the flat surface portion on the support member side of the second snap ring are approximately. A snap ring of a hydraulic friction engagement device for a vehicle, wherein the snap ring is used so as to be parallel to each other.   The coefficient of friction between the flat surface portion on the support member side of the second snap ring and the contact surface between the flat surface portion of the annular groove into which the second snap ring is fitted is determined by the first snap ring and the second snap ring. 2. The snap ring for a hydraulic friction engagement device for a vehicle according to claim 1, wherein the snap ring has a smaller coefficient of friction between contact surfaces when the snap rings are overlapped.

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