CN-114251394-B - Wet friction disk and friction engagement device

CN114251394BCN 114251394 BCN114251394 BCN 114251394BCN-114251394-B

Abstract

The invention provides a wet friction disk and a friction engagement device. The wet friction disk (1) includes a friction surface and a lubrication groove through which a lubricant supplied to the friction surface flows. The lubrication groove has a plurality of circumferential groove portions extending in the circumferential direction and a plurality of intersecting groove portions extending in a direction intersecting the circumferential direction. At least one circumferential groove portion has a through hole extending through the wet friction disc between an opposing surface facing the mating member and a surface on an opposite side in the axial direction.

Inventors

TAKEUCHI KANJI
ZHAI YEBO
UEMURA KAZUAKI
NAKAMURA TAKESHI
YOSHIMURA TAKAYOSHI
MICHISHITA MASAYA

Assignees

株式会社捷太格特
丰田自动车株式会社

Dates

Publication Date: 20260505
Application Date: 20210918
Priority Date: 20200923

Claims (3)

1. A wet friction disk (1), characterized by comprising: A friction surface frictionally sliding on a mating member disposed to face the wet friction disk in an axial direction, and A lubrication groove provided in an opposing surface facing the mating member, and through which a lubricant supplied to the friction surface flows, wherein: The lubrication groove has a plurality of circumferential groove portions extending in a circumferential direction and a plurality of intersecting groove portions extending in a direction intersecting the circumferential direction; At least one of the plurality of circumferential groove portions has a through hole extending through the wet friction disc between the opposing surface and a surface on an opposite side in the axial direction; the plurality of circumferential groove portions includes a plurality of first circumferential groove portions having an arc shape and a second circumferential groove portion provided along the entire circumference; the intersection groove portion includes a plurality of first intersection groove portions and a plurality of second intersection groove portions having a larger flow passage cross-sectional area than the plurality of first intersection groove portions, and The through hole is provided to open in the second circumferential groove portion at a position between a pair of second intersecting groove portions adjacent to each other in the circumferential direction among the plurality of second intersecting groove portions at a position spaced apart from the pair of second intersecting groove portions.
2. The wet friction disk (1) according to claim 1, wherein the through hole is provided to open at a central position in the circumferential direction between a pair of second intersecting groove portions adjacent to each other in the circumferential direction among the plurality of second intersecting groove portions.
3.A friction engagement device characterized by comprising: wet friction disc (1) according to any one of claims 1 to 2; a mating member provided so as to face the wet friction disk (1) in the axial direction, and A magnetic coil arranged beside the wet friction disc (1) and the matching member in the axial direction, wherein: Each of the wet friction plate (1) and the matching member is made of a soft magnetic material and constitutes a magnetic circuit of magnetic flux that is generated as current is applied to the magnetic coil; The magnetic circuit is configured to have a pair of first magnetic circuit portions passing through the wet friction plate and the matching member in the axial direction, and a pair of second magnetic circuit portions provided at positions spaced apart from each other in the radial direction, the pair of second magnetic circuit portions connecting the pair of first magnetic circuit portions to each other at both ends, and The through hole is provided in a region between the pair of first magnetic circuit portions in the radial direction.

Description

Wet friction disk and friction engagement device Technical Field The present invention relates to a wet friction disk and a friction engagement device. Background Wet friction discs sliding on mating members in an environment where lubricant is present are used in vehicles, such as in clutch devices that transfer torque between rotating members of a drive system and brake devices that brake rotation of the rotating members. For example, japanese unexamined patent application publication 2016-211713 (JP 2016-211713A) discloses an apparatus that includes inner and outer plates as wet friction plates that are switchable between a state of frictional engagement with each other and a state of non-frictional engagement with each other in an environment in which a lubricant is present, and that brakes rotation of a shaft relative to a housing member. The lubricating oil is used to reduce frictional heat generated between the inner and outer plates that slide against each other, abrasion of these plates, and the like. From the viewpoint of improving the responsiveness, the clutch device and the brake device in which the inner and outer plates are lubricated as described above require quick discharge of lubricating oil from between the inner and outer plates at the timing of switching between the non-friction engagement state and the friction engagement state. Specifically, when the inner and outer plates are switched from the non-friction-engaged state to the friction-engaged state, the lubricating oil needs to be rapidly discharged from between the inner and outer plates to rapidly establish friction engagement between the plates. When the inner and outer plates are switched from the friction engagement device to the non-friction engagement state, the lubricant oil needs to be rapidly discharged from between the inner and outer plates to alleviate the reduction in responsiveness due to damping torque caused by the viscosity of the lubricant oil existing between these plates. To meet this demand, the device disclosed in JP2016-211713A has lubrication grooves provided in the surface of an inner plate facing an outer plate, the inner plate rotating integrally with a shaft to which rotation is input. The lubrication grooves serve to separate lubricating oil from between the inner plate and the outer plate toward the outer peripheral side by centrifugal force applied when the inner plate rotates. Here, the lubrication grooves described in JP2016-211713A are provided in a lattice pattern at an angle with respect to both the radial direction and the circumferential direction of the inner plate. Fig. 12 is a schematic diagram indicating, with arrows, the flow of lubricating oil when lubrication grooves are provided in the inner panel in a lattice pattern similar to the pattern described in JP 2016-211713A. In fig. 12, the region in which the lubricating oil flows at a higher flow rate is indicated by a larger arrow. As shown in fig. 12, in the inner plate 9, most of the lubricating oil flowing through the lubrication groove 91 rotates in an oblique direction toward the outer peripheral side (i.e., the upper side of the drawing) and appropriately toward the opposite side of the rotation direction R of the inner plate 9 as the inner plate 9 rotates. This is because the force combining the inertial force of the lubricating oil that tries to remain stationary against the rotation of the inner plate 9 and the centrifugal force applied when the inner plate 9 rotates acts in the direction along the oblique direction, and the lubricating oil is subjected to this force acting in the oblique direction. However, the lubricating oil flowing to the intersections in the lubrication grooves 91 of the lattice pattern hits the corners 921 of the bosses 92 of the inner panel 9 defined by the lubrication grooves 91, and part of the lubricating oil branches toward the inner peripheral side in the radial direction. Therefore, the lubricating oil existing between the inner plate 9 and the outer plate may be hindered from being effectively discharged toward the outer peripheral side. Here, the lubrication grooves may also be configured in a lattice pattern simply by using annular circumferential groove portions extending in the circumferential direction and intersecting groove portions intersecting with these circumferential groove portions. This configuration can reduce the possibility that lubricating oil may flow to the inner peripheral side by striking the corner of the boss when the inner plate rotates. However, when the circumferential groove portion is provided along the entire circumference, unless a specific means is adopted, the lubricating oil flowing through the circumferential groove portion in the circumferential direction cannot be smoothly discharged toward the outer circumferential side. Therefore, there is room for improvement from the viewpoint of effectively discharging the lubricating oil existing between the inner plate an