JP5078927B2 - Double cone type synchromesh device - Google Patents

Description

The present invention relates to a structure of a double cone type synchromesh device used for a manual transmission or the like, particularly a synchromesh hub.

Conventionally, a synchromesh device is known as a clutch mechanism for shifting a manual transmission. There are various types of synchromesh devices. Among them, the double cone type synchromesh device has a larger capacity to synchronize than a single cone type synchromesh device called inertia lock type (Borgwarner type). Therefore, smooth and quick gear change is possible.

In the double cone type synchromesh device, an inner ring with a cone surface on the outer periphery, an outer ring with a cone surface on the inner periphery, and a middle ring with a cone surface on the inner and outer surfaces between the synchromesh hub and the clutch gear. And is configured to frictionally engage the cone surfaces of each other. The middle-diameter side end of the middle ring is fitted into the recess of the clutch gear and rotates together with the clutch gear.

In Patent Document 1, in a double cone type synchromesh device, when the middle ring is idle, the middle ring is provided for each cone surface of the outer ring loosely fitted on the outer peripheral side or the inner ring loosely fitted on the inner peripheral side. In order to prevent contact with one piece, an annular locking portion for restricting the axial displacement of the middle ring has been proposed at the reduced diameter side end portion of the outer ring. However, in this structure, the outer ring must be integrally formed with a locking portion that protrudes toward the inner diameter side at the diameter-reduced side end portion, so that the outer ring has a complicated shape, increases the processing cost, and increases the axial direction. There was a problem that the size increased and the compactness was hindered. Further, such a locking portion has a low mechanical strength, and the locking portion may break due to repeated load.

In FIG. 7 of Patent Document 2, a plurality of protrusions are formed in the circumferential direction on the side surface of the synchro hub, and a guide surface is formed on the tip surface of these protrusions. Is disclosed. However, the protrusion of the synchro hub has a role of guiding the centrifugal hydraulic pressure from the shaft center portion to the cone surface, and does not disclose the role of regulating the axial displacement of the middle ring.

By the way, when the protrusion on the side surface of the synchro hub shown in Patent Document 2 is used to restrict the axial displacement of the middle ring, there is a possibility that a problem may occur due to its structure. That is, although a metal sintered product is generally used for the synchro hub, when a double cone type synchromesh device is configured on both sides of the synchro hub, the protrusions must be formed on both the front and back sides of the synchro hub. However, if the protrusions are to be formed at the same position on the front and back sides, the degree of filling of the protrusions may be insufficient when the metal powder is compression molded before sintering. That is, the protrusion is a recess when viewed from the mold side, and the metal powder is compressed without being emphasized sufficiently in the recess. When such a molded body is sintered, there is a problem that the strength of the protrusions cannot be sufficiently secured. In order to secure the strength of the protrusions, for example, it is possible to perform multi-stage compression molding using a plurality of molds, but there is a problem that the molding cost increases.

Japanese Utility Model Publication No. 6-59631 Japanese Utility Model Publication No. 3-6155

An object of the present invention is to provide a synchromesh device that can easily secure the strength of a protrusion when a protrusion for restricting axial displacement of a middle ring is formed on both side surfaces of a synchromesh hub.

To achieve the above object, the present invention provides a synchro hub having an outer spline on the outer periphery, a clutch gear arranged adjacent to both sides of the synchro hub, and a relative rotation within a certain range with respect to the synchro hub. An inner ring having a cone surface on the outer periphery, an outer ring having a cone surface on the inner periphery and having spline teeth on the outer periphery, and an inner ring cone on the inner and outer periphery upon receiving a speed change operation. A middle ring that engages with the clutch gear and rotates integrally with the clutch gear, a synchro sleeve that is spline-fitted to the synchro hub, and an outer periphery of the synchro hub. When the synchro sleeve is operated in the axial direction and the outer ring rotates synchronously with the clutch gear. In the double cone type synchromesh device, in which the synchromesh sleeve is engaged with the spline teeth of the outer ring and the clutch gear to engage with each other, the synchromesh hub is formed of sintered metal, and both side surfaces of the synchromesh hub are formed. In addition, a plurality of protrusions for axially regulating the small-diameter side end face of the middle ring are formed, and the protrusions on the front and back sides are formed at positions shifted in phase on the opposite side in the circumferential direction with the key groove in between. The double cone type synchromesh device is provided.

  The inner ring and middle ring, and the outer ring and middle ring are frictionally engaged with each other on the cone surface, so the capacity during synchronization is doubled compared to a single-cone synchromesh device, enabling smooth and quick gear changes. Become. The both sides of the synchro hub are formed with a plurality of protrusions that axially regulate the small-diameter side end face of the middle ring, and by controlling the axial displacement of the middle ring by these protrusions, Further, it is possible to prevent the middle ring from colliding with each cone surface of the outer ring or the inner ring. Since the protrusions of the synchro hub are formed at positions where the phases are shifted to the opposite sides in the circumferential direction with the key groove in between, the protrusions on the front and back sides can be arranged at intervals in the circumferential direction. Therefore, when the synchro hub is compression-molded, the degree of powder filling in the protrusions can be ensured, and the protrusions with no strength reduction after sintering can be formed.

A claw portion that protrudes in the axial direction is formed at the small diameter side end portion of the inner ring, and the synchro hub has a plurality of holes or concave portions that engage with the claw portion of the inner ring in the circumferential direction. It is desirable to form in the area | region between the circumferential direction of a hole or a recessed part and the said keyway. It is necessary to rotate the inner ring integrally with the synchro hub. For this purpose, an inner cone hub is provided on the inner diameter side of the inner ring via a pin as in Patent Document 1, and this inner cone hub is adjacent to the synchro hub. There is also a method of spline coupling to the main shaft, but this increases the number of parts and complicates the structure. On the other hand, if a hole or a recess is provided in the synchro hub as described above, and the claw portion formed at the small-diameter end of the inner ring is directly engaged with this hole or recess, the structure is simple and compact. Therefore, the number of parts can be reduced. Furthermore, since the protrusion is formed in a region between the hole or the recess and the key groove in the circumferential direction, the protrusion can be formed in a marginal space, and the circumferential length of the protrusion can be secured. .

As described above, in the double cone type synchromesh device according to the present invention, the middle ring axial displacement restricting protrusions are formed on both side surfaces of the synchro hub made of sintered metal, and these protrusions are interposed between the key grooves. Thus, since the phase is formed at a position shifted in the opposite direction in the circumferential direction, it is possible to ensure the degree of filling of the protrusions at the time of compression molding, and it is possible to form protrusions that do not decrease in strength after sintering.

It is sectional drawing in the neutral position of an example of the synchromesh apparatus concerning this invention. It is sectional drawing which assembled | attached the inner ring, middle ring, and outer ring of the synchromesh apparatus shown in FIG. It is a front view of the synchromesh hub of the synchromesh apparatus shown in FIG. It is sectional drawing of the projection part of the synchro hub shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to examples.

  1 and 2 show an example in which an example of a double cone type synchromesh device according to the present invention is applied to a 1-2 speed transmission portion of a manual transmission. FIG. 1 shows a neutral state.

1 and 2, the main shaft 1 is spline-fitted with a sync hub 2 having an outer spline 2a on the outer periphery, and variable speed gears 3, which are rotatably supported on the main shaft 1 on both sides of the sync hub 2. 4 is arranged. The transmission gears 3 and 4 are integrally formed with clutch gears 3 a and 4 a on opposing inner surfaces. Cylindrical support portions 3b and 4b extending in the opposite direction are formed on the inner peripheral surface of the transmission gears 3 and 4 from the clutch gears 3a and 4a, and cone surfaces 5a and 6a are formed on the outer periphery thereof. Inner rings 5 and 6 are supported so as to be relatively rotatable. A plurality of (in this case, three at 120 ° intervals) claw portions 5b, 6b are integrally formed at the small diameter side ends of the inner rings 5, 6 and the claw portions 5b, 6b are synchronized with each other. A plurality of through holes 2b formed in the circumferential direction in the hub 2 are inserted with a circumferential gap. Therefore, the inner rings 5 and 6 can rotate relative to the synchro hub 2 within a certain angle range. The large-diameter side end surfaces of the inner rings 5 and 6 are axially restricted by the inner surfaces of the clutch gears 3a and 4a. As shown in FIG. 2, spiral grooves 5c and 6c (6c not shown) are formed on the inner peripheral surfaces of the inner rings 5 and 6, and when they rotate relative to the clutch gears 3a and 4a, lubrication described later is performed. The oil spreads in the axial direction via the grooves 5c and 6c, and is configured to reduce wear between the clutch gears 3a and 4a.

Outer rings 7 and 8 having cone surfaces 7a and 8a on the inner periphery and spline teeth 7b and 8b on the outer periphery are disposed on the outer periphery of the inner rings 5 and 6. In the radial gap between the inner rings 5 and 6 and the outer rings 7 and 8, middle rings 9 and 10 having cone surfaces 9a and 9b and 10a and 10b on the inner and outer circumferences are arranged. The inner ring side cone surfaces 9a, 10a of the middle rings 9, 10 are in contact with the cone surfaces 5a, 6a of the inner rings 5, 6, and the outer ring side cone surfaces 9b, 10b are connected to the cone surfaces 7a, 8a of the outer rings 7, 8. Contact. Plural (here, three at 120 ° intervals) claw portions 9c and 10c are provided in the axial direction at the large diameter side ends of the middle rings 9 and 10, and these claw portions 9c and 10c are connected to the clutch gears 3a and 4a. Are inserted into the recesses 3c, 4c. Therefore, the middle rings 9 and 10 are connected to the clutch gears 3a and 4a so as to be integrally rotatable. In this example, the recesses 3c and 4c of the clutch gears 3a and 4a are grooves formed in a plurality of locations in the circumferential direction of the clutch gears 3a and 4a, but the claw portions 9c and 10c are engaged with the inner side surfaces of the clutch gears 3a and 4a. A matching hole may be formed.

As shown in FIG. 3, a plurality of (three in this example) key grooves 2c are formed in the outer spline 2a of the sync hub 2 in the circumferential direction, and the sync keys 11 are fitted into the key grooves 2c, respectively. Yes. Three key grooves 2c and two through holes 2b of the synchro hub 2 are formed at different positions of 120 ° phase, and the key grooves 2c and the through holes 2b are different in phase by 60 °. In FIG. 1, the sync key 11 and the through hole 2 b are shown in the same phase for simplification of illustration. A plurality of protrusions 2d, 2e for restricting the axial position of the small-diameter end faces of the middle rings 9, 10 are intermittently formed in the circumferential direction on both front and back side surfaces of the synchro hub 2, and the front and back protrusions 2d, 2d, 2e is formed in the position which does not mutually oppose. In particular, the front and back protrusions 2d, 2e are out of phase in the circumferential direction opposite to each other with the key groove 2c therebetween, and are formed in an intermediate region in the circumferential direction between the through hole 2b and the key groove 2c. In this example, the protrusions 2d and 2e have a phase difference of 22 ° with respect to the key groove 2c (38 ° with respect to the through hole 2b), but this is not restrictive.

On both sides in the circumferential direction of the protrusions 2d and 2e, as shown in FIG. 4, inclined surfaces 2d1 and 2e1 in the circumferential direction toward the upper end surface are formed. This inclination angle θ is set to 30 ° ± 5 °. A shaft center oil passage 20 is formed in the main shaft 1, and lubricating oil is supplied from the shaft center oil passage 20 to the outer peripheral surface of the main shaft 1 through the radial oil passages 21 and 22. Further, the lubricating oil is supplied to the gap between the transmission gears 3 and 4 and the synchromesh hub 2 and flows outward in the radial direction by centrifugal force to lubricate the synchromesh device. By forming the inclined surfaces 2d1 and 2e1 on both sides in the circumferential direction of the protrusions 2d and 2e, when there is a differential rotation between the synchro hub 2 and the transmission gears 3 and 4, the lubricating oil is caused by the centrifugal force by the protrusions 2d and 2e. It becomes easy to flow on the upper surface of 2e (the surface facing the middle rings 9, 10), and the slidability between the projecting portions 2d, 2e and the end surfaces on the small diameter side of the middle rings 9, 10 is improved.

The synchro hub 2 is a sintered product obtained by compressing and molding metal powder and then sintering. When compression molding is performed, a pair of molds are compressed from both the front and back sides. When the projecting portions 2d and 2e are in positions facing each other, the packing density of the powder into the recesses of the mold for forming the projecting portions Decreases, leading to a decrease in strength of the protrusions 2d and 2e after sintering. In the present invention, since the protrusions 2d and 2e on the front and back sides are formed out of phase with each other, it is possible to prevent the filling density in the recesses of the mold from being lowered and to form the strong protrusions 2d and 2e. Since the front and back projections 2d and 2e are alternately formed in the area between the through hole 2b and the key groove 2c in the circumferential direction, the projections 2d and 2e can be formed in a marginal space, and the projection 2d , 2e can be secured. Furthermore, since inclined surfaces 2d1 and 2e1 of 30 ° ± 5 ° are formed on both sides in the circumferential direction of the protrusions 2d and 2e, the surrounding powder enters the recesses of the mold for forming the protrusions. It becomes easy. As a result, high strength projections 2d and 2e can be formed during sintering.

A convex portion 11 a is formed on the outer peripheral surface of the central portion of the sync key 11. A pair of key springs 12 are disposed on the inner diameter portion of the synchro key 11, and the synchro key 11 is always urged in the outer circumferential direction. Both end portions of the synchro key 11 are engaged with recesses 7 c and 8 c formed on the inner side surfaces of the outer rings 7 and 8, whereby the outer rings 7 and 8 and the sync hub 2 are connected via the sync key 11. It is configured to rotate integrally.

The inner spline 13a of the synchro sleeve 13 is fitted to the outer spline 2a of the synchro hub 2 so as to be slidable in the axial direction. On the inner peripheral surface of the central portion of the inner spline 13a of the synchro sleeve 13, an inner peripheral groove 13b into which the convex portion 11a of the synchro key 11 is fitted is formed. When the synchro sleeve 13 is operated in the axial direction by a shift fork (not shown), when the outer rings 7 and 8 rotate in synchronization with the clutch gears 3a and 4a, the synchro sleeve 13 is splined 7b of the outer rings 7 and 8. , 8b can be engaged with the clutch gears 3a, 4a to selectively connect the sync hub 2 and one of the transmission gears 3, 4.

  As described above, the inner rings 5 and 6 are supported while being regulated in the axial direction, whereas the middle rings 9 and 10 and the outer rings 7 and 8 are fitted with a margin in the axial direction. As the wear progresses, backlash occurs in the inclined direction. If the play exceeds a certain allowable limit, the middle rings 9 and 10 are likely to come into contact with each cone surface of the outer rings 7 and 8 or the inner rings 5 and 6 when the middle rings 9 and 10 idle. May cause unpleasant noise and uneven wear. On the other hand, since the protrusions 2d and 2e for restricting the position of the small-diameter side end surfaces of the middle rings 9 and 10 in the axial direction are formed on the side surfaces of the synchro hub 2, the middle rings 9 and 10 are prevented from falling down. The contact between the surfaces can be suppressed. Therefore, unpleasant noise and uneven wear can be prevented.

The present invention is not limited to the above embodiment. In the above embodiment, the both ends of the key are engaged with the recesses of the outer ring, and the synchro hub and the outer ring are rotated integrally. However, the claw portion is provided at the small diameter side end portion of the outer ring. The synchro hub and the outer ring may be integrally rotated by engaging the synchro hub with the synchro hub. In that case, for example, a recess or a groove may be formed on the synchro hub side. Further, the inner ring small diameter side end was inserted into the through hole of the synchro hub to prevent rotation, but a protrusion was formed on the synchro hub side, and this convex part was formed on the small diameter side end of the inner ring or The rotation may be prevented by engaging with the groove.

DESCRIPTION OF SYMBOLS 1 Main axis | shaft 2 Synchro hub 2a Outer spline 2b Through hole 2c Key groove 2d, 2e Protrusion part 3, 4 Transmission gear 3a, 4a Clutch gear 3c, 4c Recessed part 5, 6 Inner ring 5a, 6a Cone surface 5b, 6b Claw part 7, 8 Outer rings 7a, 8a Cone surfaces 7b, 8b Spline teeth 7c, 8c Recesses 9, 10 Middle rings 9a, 9b, 10a, 10b Cone surfaces 9c, 10c Claw portion 11 Sync key 12 Key spring 13 Sync sleeve

Claims (2)

A synchro hub having an outer spline on the outer periphery, a clutch gear arranged adjacent to both sides of the synchro hub, an inner ring having a cone surface on the outer periphery, which is arranged to be relatively rotatable with respect to the synchro hub within a certain range. In response to the speed change operation, it is displaced in the axial direction, and has an outer ring having a cone surface on the inner periphery and spline teeth on the outer periphery, and an inner ring cone surface and an outer ring cone surface on the inner and outer periphery, respectively. A middle ring that has a cone surface and rotates integrally with the clutch gear, a synchro sleeve that is spline-fitted to the synchro hub, and a synchro key that is disposed in a keyway formed on the outer periphery of the synchro hub. When the synchro sleeve is operated in the axial direction, the synchro sleeve is moved to the outer ring when the outer ring rotates synchronously with the clutch gear. In the spline teeth and spline-fitted to the clutch gear of the double-cone synchromesh device for performing engagement,
The synchro hub is formed of a sintered metal, and a plurality of protrusions for axially regulating the small-diameter side end surfaces of the middle ring are formed on both front and back side surfaces of the synchro hub. A double-cone synchromesh device characterized in that it is formed at a position where the phase is shifted to the opposite side in the circumferential direction with a keyway in between. A claw portion protruding in the axial direction is formed at the small diameter side end portion of the inner ring,
The synchro hub is formed with a plurality of holes or recesses in the circumferential direction to engage the claw portions of the inner ring,
The double cone type synchromesh device according to claim 1, wherein the protrusion is formed in a region between a circumferential direction of the hole or recess and the key groove.

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