FR3077358A1 - MECHANICAL LOCKING DEVICE OF A TRANSMISSION SHAFT IN PARKING POSITION - Google Patents

Abstract

Mechanical locking device (1) of a transmission shaft (10) of a motor vehicle comprising at least: - a parking wheel (5) integral with the transmission shaft, - a wheel locking lever ( 5) pivoting about an axis between at least one locking position and a release position of the wheel, - a longitudinal control rod (3) having an end loosely connected to a control plate (2) of the control device. mechanical blocking, - a sliding pusher on the rod (3) and biased by a spring against a guide stopper arresting the rod and the pusher upwards, characterized in that the device comprises means for limiting movement (2c, 11) constraining the free end of the rod (3) against the stop by pressing on the control plate (2), as long as the mechanical locking device is not actuated.

Description

MECHANICAL LOCKING DEVICE OF A TRANSMISSION SHAFT IN PARKING POSITION

The present invention relates to a mechanical locking device of a drive shaft in the parking position.

It relates more particularly to a mechanical blocking device for a motor vehicle transmission shaft, comprising at least:

a parking wheel secured to the drive shaft,

a wheel locking lever, pivoting about an axis, between at least one locking position and a wheel release position,

- a longitudinal control rod having one end linked with play to a control plate of the mechanical locking device,

- a push rod sliding on the rod, biased by a spring against a guide stop stopping the rod and the push rod upwards.

The parking wheel locking devices are generally actuated from a control system, or gear selector, by the driver.

The publication FR 3 044 064 discloses a mechanical locking device for a drive shaft controlled by the driver's speed selector. The selector acts on an axis which causes the pivoting of an angular sector of billing between different driving modes, such as a parking mode (P), a neutral neutral mode (N), a reverse mode (R ) or "reverse", and a forward (D) or "drive" mode.

The blocking device is only active in the parking mode (P). It rotates to lock the drive shaft, to immobilize the vehicle, preventing it from moving, thanks to the engagement of its parking brake.

When the parking mode (P) is not sought, the parking wheel is free with respect to the locking device. It is rotated by the drive shaft. The locking lever is kept away from the wheel in a release position by a return spring. This spring prevents any unexpected movement of the lever. It prevents the finger from coming into contact with the parking wheel in other operating modes than the parkinq mode, for example following impacts, or in response to vehicle vibrations.

With reference to FIGS IA and IB, the selector (not shown) rotates the axis 1 secured to the control plate 2, which is an ancillary sector of billaqe. The trinqle is fixed with play on the sector 2. When the driver activates the change of position, the control sector 2 rotates, causing the trinqle to move. The trinqle 3 carries a chamfered movable pusher 7, sliding thereon under the pressure of a spring 8. Outside the position P (Park), the pusher 7 is stopped by a quidaqe stop, or diabolo 6. The request to set position P, causes the sector to rotate, and load the spring 8. When the position P is close, the energy of the spring 8 causes the pusher 7 to pass under the stopper 6. The pusher 7 has the 'energy of the spring 8, to push the doinq of parkinq 4 downwards, to meet the parkinq wheel 5. The latter is fixed to a shaft of the transmission 10, visible on the figure IB. The doiqt tries to introduce itself between the teeth 5b of the wheel 5. The load of the spring 8 gives a high speed of ejection to the pusher 7. The ejection of the doiqt 4 towards the wheel 5, can then be violent, and dissociate this one, the toast 3 and the pusher 7.

When the parkinq brake mechanism is positioned in the upper part of the box, the trinqle 3 tends to follow the movements of the doiqt 4. When driving at high speed, the doiqt can try to fit into the wheel, without the the parkinq brake is sought. But it is systematically ejected. The trinqle falls by qravity. It is struck by the doiqt, which is ejected by the wheel. The repetition of this so-called “racheting” phenomenon can cause the stub to be broken.

The present invention aims to eliminate this phenomenon, by limiting the travel of the trinqle.

For this purpose, the proposed device comprises means constraining the free end of the rod against the stop, by pressing on the control plate, as long as the mechanical blocking device is not actuated.

These means can either be incorporated into the metering sector, or added to it.

The present invention will be better understood on reading the following description of a non-limiting embodiment thereof, with reference to the appended drawings, in which:

FIGS. IA and IB are respectively side and top views of a transmission shaft locking device,

FIG. 2 shows a first metering sector,

figures 3 and 4 illustrate a first fashion of inventing we, and Figures 5 and 6 illustrate a second fashion of realization of it. The device mechanical blocking of brake car park

1, of a motor vehicle, illustrated by Figures IA and IB, comprises a parking wheel 5, integral in rotation with a transmission shaft 10 of the vehicle. The parking wheel 5 has internal grooves 5a intended to cooperate without play with the one torque transmission shaft 10, acting between the vehicle engine, and the drive wheels.

The device 1 is supported by a frame (not shown) comprising a fixed guide stop 6 of elongated shape, orthogonal to the transmission shafts of the gearbox and to the parking wheel 5. The guide stop 6 is cylindrical in revolution. It generally presents a form of “hourglass” or “diabolo”. In the middle zone along the axis of the stop, a groove 6a is formed by two truncated cones linked to their apex.

The frame of the device comprises an axis of rotation A, of transverse orientation, on which a parking finger 4, or locking lever 4, is mounted in rotation by one end. At its other end, the finger 4 has a catch notch 4a and a shoulder 4b. The notch 4a is of complementary shape to the slots 5c separating the teeth 5b from the parkinq wheel 5. The shoulder 4b abuts against the pusher 7 in the high position.

from in

Leverage 4 rotates around the axis AT, Between a position of blocaqe of the wheel 5, in which the notch 4 a is enqaqé in the teeth parkinq wheel r and an position of release of the wheel 5, in which the the sink 4 is discarded of wheel 5. The actuation means of the sink 4 include the trinqle 3 the pusher 7, the spring of preload 8, and the

end

31, an elbow and an abutment 6. The trinqle 3 presents inqaqée in the sector 2.

conductor, or actuator,

This moves contact with the automatically

The rotation control command of the met

A sector the trinqle 3. lever 4, is mounted against its means

Pusher 7 is

It is biased against return spring 9, on the axis the lever 4 in the actuation position.

A. It recalls release, movable at stop 6 a translation stop

8, which rests on Up to the pass in position P (Park), by the stop of quidaqe 6.

When the position P push on the trinqle. by the rear preload spring 32 of the trinqle 3.

is stopped is pass the

The energy of the spring under the pusher 7

This movement preloads the attack, the energy of the spring 8 makes the stop. The push button the doiqt 4 push meets the wheel for parkinq. The notch 4a of the worm has the bottom to the tent then to enter

The second tray 2 from billaqe, the trinqle.

doiqt parkinq.

shows an example of the geometry of a sector such as that of the IA and IB figures. The between the teeth of the billing wheel 2, has a first hole 2a for the passaqe of the axis and a second hole 2b for the passaqe of the axis of

Its lateral profile cooperates with a billing device (visible on figure 5) to define the different functional positions of the control, such as the usual P / R / N / D positions (Parking, Reverse for Reverse, Neutral for neutral or neutral, and Drive for forward). It is designed to provide the speed and strength required to fit each of these positions. Sector 2 also makes it possible to transform the rotational movement of the control axis 1 into a translational movement of the parking finger 4, to engage the Park position. It moves with the rod 3. The proposed device thus comprises travel limiting means which constrain the free end of the rod 3 against the stop 6, by pressing on the control plate 2, as long as the mechanical locking device n is not activated.

In Figure 3, there is shown a billing sector 2 according to a first embodiment of the invention. It has a travel limiting arm 2c integrated into the billing sector 2. The sector 2 moves with the rod 3. Its arm 2c, visible in FIGS. 3 and 4, limits the movement of the finger 4 in the direction of the rod 5. The arm 2c constrains the free end 32 of the rod 3 against the stop 6, by pressing on the control plate 2.

In a second embodiment of the invention, illustrated by FIGS. 5 and 6, the means limiting the deflection of the rod are in the form of a spring leaf 11, attached to the sector 2. The blade 11 repels elastically the rod 3 and the pusher 7 towards the stop 6.

In summary, the proposed device is a mechanical blocking device for a drive shaft 10 of a motor vehicle comprising at least:

a parking wheel 5 secured to the transmission shaft 10, a locking lever 4 of the wheel 5 pivoting about an axis between at least one locking position and a release position of the wheel 5,

a longitudinal control rod 3 having an end 3 linked with play to a control plate 2 of the mechanical locking device, and

- A pusher 7 sliding on the rod 3, biased by a spring 8, against a guide stop 6 stopping the rod 3 and the pusher 7 upwards.

According to the invention, this device comprises means which constrain the free end 2 of the rod 3 against the stop, by pressing on the control plate, as long as the mechanical locking device is not actuated.

These means are produced for example in the form of an arm 2c incorporated in the control plate 2, or of a leaf spring attached to it. However, these two embodiments have no limiting character. Without departing from the scope of the invention, they can take other forms not described, which are determined by the definition of the parking brake.

The calibration of the spring leaf, or a more or less domed shape, determines the level of stress imposed. However, the means limiting the travel must be able to accompany the movement of the rod, throughout its longitudinal displacement.

The advantages of the invention are numerous. Among these, mention should be made of the reduced size of the added means. The integration of the function increases the reliability of the control device, in particular at the level of its rod, with or without the addition of an additional part, depending on the embodiment chosen. In both cases, this result is obtained without modifying the existing architecture or the kinematics.

Claims (5)

1. Mechanical locking device (1) of a drive shaft (10) of a motor vehicle comprising at least: a parking wheel (5) integral with the drive shaft (10), a locking lever (4) of the wheel (5) pivoting about an axis between at least one locking position and a position for releasing wheel, - a longitudinal control rod (3) having one end (31) connected with clearance to a control plate (2) of the mechanical locking device, a pusher (7) sliding on the rod (3) and biased by a spring against a guide stop (6) stopping the rod (3) and the pusher (7) upwards, characterized in that the device comprises travel limiting means (2c, 11) constraining the free end of the rod (3 ) against the stop (6) by pressing on the control plate (2), as long as the mechanical locking device is not actuated. 2. Mechanical locking device (1) according to claim 1, characterized in that the travel limiting means are produced in the form of an arm (2c) incorporated in the control plate (2). 3. Mechanical locking device (1) according to claim 1, characterized in that the travel limiting means are attached to the control plate (2). 4. Mechanical locking device (1) according to claim 3, characterized in that the movement limiting means consist of a leaf spring (11) attached to the control plate (2). 5. Mechanical locking device (1) according to one of the preceding claims, characterized in that the movement limiting means accompany the movement of the rod (3).