JPH0322052Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention and Field of Application] The present invention relates to a braking force retention device for a vehicle.

[Conventional examples and their problems]

As shown in Fig. 1, the braking force retention device for a vehicle is provided with a rack gear 3 that can swing around a bolt 2 on a bracket 1 fixed to a dash board (not shown), and a tooth is attached to the upper edge of a window in the center of the rack gear. 4
A pinion gear 5 is engaged with the teeth 4, and the pinion gear 5 is fixed to a shaft 7 via a spline 6, so that the shaft 7 can freely rotate in the direction in which the brake pedal is depressed but cannot rotate in the opposite direction. Some have a structure in which they are supported by a hub 9 via a one-way clutch 8. In this case, the shaft 7 is prevented from moving to the right in the figure relative to the hub 9 by a stop shaft 10 fixed to the shaft 7, and a plurality of pins 11 implanted at the right end of the hub 9 in the figure A spacer 12, a spring 13 and a clutch plate 14 are inserted, and a washer 15 inserted into the shaft 7 so as to be movable in the axial direction is pressed against the clutch plate 14 by a spring 16. The spring 16 is interposed between a spring presser 17 fixed to the shaft 7 and the washer 15. The washer 15 is brought into contact with the spacer 12 by the force of a spring 16. The spacer 12 is disposed between the hub 9 and the clutch plate 14, and the spacer 12
The left end surface in the figure is in contact with a bearing member 18 rotatably supported by the hub 9.

A yoke 19 and an electromagnet 22 having a coil 20 and a friction material 21 are supported on the bearing member 18 . A lead wire 23 is connected to the coil 20.

The left end of the bearing member 18 in the figure contacts a mounting plate 25 that supports the hub 9 and is fixed to the bracket 1 by bolts 2 and 24, and the right end of the bearing member 18 contacts a yoke 19, and the electromagnet 2
2 is fixed to a mounting plate 25. A cover 25 is attached to the end of the yoke 19 on the friction material 21 side.

The clutch plate 14 is moved by the friction material 2 due to the force of the spring 13.
Although it is given the habit of moving away from 1, spring 13
is set smaller than the force of the spring 16.

In the conventional braking force holding device having such a structure, the shaft 7 is positioned with respect to the clutch plate 14 via the spring 16, the washer 15, and the spring retainer 17, and the shaft 7 is positioned with respect to the hub 9 using the retaining ring 10, for example. Since this is done using an E-ring, it is not possible to maintain a constant clearance between the clutch plate 14 and yoke 19. Therefore, when a force is applied to the pinion gear 5 in the direction of disengagement, the clutch plate 14 is pressed against the yoke 19, causing a dragging phenomenon of the electromagnetic clutch, which causes failure of the brake pedal to return.

[Technical issues of the present invention and its technical means]

SUMMARY OF THE INVENTION An object of the present invention is to provide a braking force retaining device having an electromagnetic clutch whose gap can be adjusted so that the gap between the yoke of the electromagnetic clutch and the clutch plate can be maintained at a predetermined distance.

The technical means of the present invention to solve this problem is to use a stepped shaft, install a bracket between the pinion gear and the stepped portion of the shaft, and fix the pinion gear to the shaft while being pressed against the bracket. The hub is attached to the shaft with the left end of the hub in contact with the bracket.

[Operations and effects of the present invention]

With this invention, the relative position of the shaft to the bracket is set by holding the bracket between the stepped part of the shaft and the pinion gear fixed to the shaft, and therefore the relative position of the yoke and the shaft is kept constant. Since the relative position of the clutch plate with respect to the hub and shaft can be set by the spacer, the spring, and the washer, the clearance between the clutch plate and the yoke can be maintained constant. Even if a force in the pulling direction is applied to the pinion gear, the relative position between the shaft and the bracket does not change, so the clutch plate will not be pushed toward the yoke. Therefore, the drag of the electromagnetic clutch is eliminated.

According to the present invention, the clearance between the yoke and the clutch plate is kept completely constant, so that the contact noise when the yoke and the clutch plate make contact can be kept constant and low.

Since no axial force acts on the one-way clutch, the durability of the one-way clutch can be extended.

Since the drag of the plate is small and constant, there is less wear on the plate and yoke, and the holding force is stable.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and descriptions of the same components as in FIG. 1, which are not subject to the present invention, will be omitted.

In FIG. 2, the shaft 7 has a large diameter portion 7a and a small diameter portion 7b.
It is formed as a stepped shaft with a and inserted into the bracket 1. Partition plates 24 and 25 are provided to sandwich the bracket 1, and the stepped portion of the shaft 7 abuts against the partition plate 24 to prevent the shaft 7 from moving to the left in the figure.

A pinion gear 5 is inserted into the small diameter portion 7b of the shaft 7, and the pinion gear 5 is fixed to the shaft 7 with a nut 26 in contact with the partition plate 25. Therefore, the shaft 7 is fixed to the bracket 1 so as not to move in the axial direction.

A hub 9 supported by a shaft 7 via a one-way clutch 8 is mounted so that its left end in the figure abuts against a partition plate 24. A washer 17 is fixed to the end of the large diameter portion 7a of the shaft 7 with a nut 27. A spacer 12, a spring 13, and a clutch plate 14 are sequentially inserted into a plurality of pins 11 implanted at the right end of the hub 9 in the drawing. The spacer 13 is connected to the spring retainer (or washer) via the washer 15 and spring 16 inserted into the large diameter portion 7a of the shaft 7.
The clutch plate 14, which is pressed against the bearing member 18 by the clutch plate 17, is pressed against the washer 15 by the spring retainer 13, and the distance between the clutch plate 14 and the friction material 21 is maintained constant.

When the electromagnet 22 is excited by electricity, the clutch plate 14 is attracted against the force of the spring 13 and the friction material 2
1 to prevent rotation of the shaft 7 and maintain braking force.

When the electromagnet 22 is demagnetized, the clutch plate 14 is pressed by the washer 15 and a predetermined distance is formed between the clutch plate 14 and the friction material 21, so that the distance can be reliably adjusted and dragging is eliminated.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional braking force holding device for a vehicle, and FIG. 2 is a sectional view of a braking force holding device according to the present invention. 1...Bracket, 5...Pinion gear, 7...
...Shaft, 8...One-way clutch, 9...Hub,
13... Spring, 14... Clutch plate, 15, 17
...Watshiya, 21...Friction material, 22...Electromagnet.

Claims (1)

[Scope of utility model registration request] A pinion gear that is rotationally driven in conjunction with depression of the brake pedal, a shaft to which the gear is fixed, an electromagnet which is fixed to a bracket as a stationary member, a bearing member that supports the electromagnet, and a rotatable pinion gear to the bearing member. a clutch plate supported by the hub through a pin so as to be movable relative to the hub in the axial direction but not rotate relative to the hub;
In a braking force holding device for a vehicle, the shaft is supported by a hub via a one-way clutch, and the clutch plate is arranged to face a friction material of an electromagnet.
The shaft has a stepped portion, and a pair of partition plates sandwiching a bracket between the stepped portion of the shaft and a pinion gear fixed to the shaft, and one partition plate is connected to the stepped portion of the other partition. A braking force holding device for a vehicle, characterized in that a plate is brought into contact with a pinion gear to prevent the shaft from moving in the axial direction, and an end surface of the hub is brought into contact with one of the partition plates.