JPS6021586Y2 - Dust-proof device for screw feed mechanism for moving automobile seats - Google Patents

Description

[Detailed description of the invention] The present invention relates to a dustproof device for a screw feed mechanism for moving an automobile seat, and is suitable for use in a device with a relatively large stroke distance, such as a slide power unit of a seat or a screw feed mechanism for pop-up of a headrest. This is a suitable device.

An example of a conventional device of this type will be explained with reference to FIG.

Reference numeral 1 denotes a drive shaft rotated by a motor (not shown) or the like, and has a threaded portion 1a, and the drive shaft 1 is supported by bearings 2 and 3.

A nut 4 engages with the threaded portion 1a, and moves in the axial direction as the drive shaft 1 rotates.

10.10 is a bellows that is a dust-proof cover for the threaded portion 1a that engages with the nut 4, and both ends of the bellows 10.10 are connected to the entire circumference R4at4a provided on the nut 4 and the bearing 2.
, 3 are engaged with the circumferential grooves 2a, 3a provided in the grooves 2a, 3a.

Note that 7 is a nut housing that holds the nut 4.

The bellows 10.10 has a complicated structure because it needs to be expandable and retractable within the stroke range, and it also requires a length that corresponds to the stroke distance, making it expensive if the stroke distance is relatively large. There was.

In addition, the bellows 10.10 has the disadvantage that it takes up a considerable amount of space in the axial direction due to its structure, and furthermore, the nut 4 and bearing 2
, 3 must be provided with circumferential grooves 4a, 4a, 2av 3a to engage both ends of each of the bellows 10.10, making it troublesome to install the bellows 10.10.

The purpose of the present invention is to provide a dustproof device for a screw feed mechanism for moving an automobile seat, which eliminates the drawbacks of the conventional device described above. A female thread having a length of at least one circumference and having a diameter slightly smaller than the outer diameter of the threaded part is held at the middle part in the axial direction of the nut in the U-shaped nut housing and is screwed into the threaded part. A cover made of an elastic material having a hole therein and prevented from rotating by the nut housing is provided on both axial end surfaces of the nut, and a stopper plate is provided on the nut housing to prevent the covers from moving in the axial direction. By wearing it, you are considered a distant relative.

The present invention will be described below with reference to an embodiment shown in the drawings.

In FIGS. 2 to 4, reference numeral 1 denotes a drive shaft rotated by a motor (not shown), etc., and has a threaded portion 1a, and the drive shaft 1 is supported by bearings 2 and 3. As shown in FIGS.

4 is a nut that engages with the threaded portion 1a.

Elastic packings 5, 5 are provided on both end faces of the nut 4 in the axial direction, respectively.
The plates 6a and 6b are fixed through the holes 7a formed in the upper and lower centers of the nut housing 7, which has a substantially U-shaped side surface, respectively, and the nut 4 is engaged with the hole 7a, and the nut 4 is secured to the nut housing. The nut 4 is held at the middle portion of the nut 4 in the axial direction.

The elastic packings 5, 5 and the plates 6a, 6b are each provided with holes for inserting the threaded portions 1a.

When the movement of the drive shaft 1 in the axial direction and the rotation of the nut housing 7 are prevented, the nut 4 moves in the axial direction together with the nut housing 7 due to the rotation of the drive shaft 1, and the nut housing 7 is fixed. When the drive shaft 1 is allowed to move in the axial direction, the rotation of the drive shaft 1 moves the drive shaft 1 and the bearings 2 and 3 together in the axial direction.

That is, as the drive shaft 1 rotates, the threaded portion 1a and the nut 4 move relative to each other in the axial direction.

8, 8 are respectively provided on both axial end surfaces of the nut 4,
This cover is for preventing dust and the like attached to the threaded portion 1a from adhering to the threaded portion between the threaded portion 1a and the nut 4, and is made of an elastic material such as rubber.

These covers 8, 8, as shown in FIGS. 3 and 4, have a pair of lip portions 8a provided at both ends of one side that abuts the axial end surface of the nut via the plate 6a or 6b and the elastic packing 5. , 8a, a female thread 8b having a length of at least one circumference and screwed into the threaded portion 1a, and a hole 8c having a diameter slightly smaller than the outer diameter of the threaded portion 1a.

A stopper plate 9 is attached to the nut housing 7 and is used to prevent the covers 8, 8 from moving in the axial direction.

Push the covers 8, 8 from both ends of the drive shaft 1 in the direction of the arrow in FIG.
Alternatively, the stopper plate 9 is brought into contact with both end surfaces of the nut 4 in the axial direction via the elastic packing 5 and the stopper plate 9.
Attach it to the nut housing 7 in the direction of arrow C.

The rotation of the covers 8, 8 is prevented by the upper and lower surfaces of the nut housing 7, which has a substantially U-shaped side surface, and the axial movement of the covers 8, 8 is prevented by the stopper plate 9.

Note that the threaded portion between the nut 4 and the threaded portion 1a of the drive shaft 1 is filled with grease.

Thus, as the drive shaft 1 rotates, the threaded portion 1a and the nut 4 move relative to each other in the axial direction. The holes 8c, 8c and the female threads 8b, 8b prevent dust, etc. attached to the top, bottom, and flank of the threaded portion 1a from entering the threaded portion of the threaded portion 1a and the nut 4, and also prevent the nut 4 and the drive. The grease filled in the threaded portion of the shaft 1 with the threaded portion 1a is prevented from leaking to the outside of the covers 8, 8.

Further, the covers 8, 8 can be stored in the nut housing 7, and space is not taken up in the axial direction as in the conventional device, making it possible to reduce the size of the device.

Furthermore, since the covers 8, 8 can be attached by simply pushing them in from the end of the drive shaft 1, work efficiency is improved.

As is clear from the above description, the dustproof device for a screw feed mechanism for moving an automobile seat according to the present invention has the following effects.

(1) Since the cover is held within the nut housing, it does not take up a large space in the axial direction as in the conventional case, making the device compact.

(11) The cover is prevented from rotating by the nut housing, which has a substantially U-shaped side surface, and is prevented from moving in the axial direction by the stopper plate, so it always remains in close contact with the axial end surface of the nut inside the nut housing. This ensures that dust attached to the threaded part of the drive shaft does not enter the threaded part between the threaded part and the nut, and that the grease filled in the threaded part is removed from the outside of the cover. It will not leak.

The book cover has a simple structure and can be obtained at low cost.
Utilizing its elasticity, the cover only needs to be pushed into the axial end face of the nut from the end of the drive shaft, and the stopper plate can be easily attached to the nut housing without interference from the drive shaft, improving installation workability. will improve.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is an exploded perspective view showing an embodiment of the present invention, Fig. 3 is a sectional view of a part of the cover in Fig. 2, and Fig. 4 It is a top view and a side view of the formed internal thread. Note that the same reference numerals in the drawings indicate the same or equivalent parts. 1...Drive shaft, 1a...Threaded part, 4.
...Natsuto, 7...Natsuto housing,
8...Cover, 8b...Female thread, 8c
...hole, 9...stopper plate.

Claims (1)

[Scope of utility model registration request] In a screw feeding mechanism for moving an automobile seat, in which a threaded portion provided on the drive shaft and a nut screwed into the threaded portion move relative to each other in the axial direction due to rotation of the drive shaft, the nut has a side surface shape approximately A female thread having a length of at least one circumference and having a diameter slightly smaller than the outer diameter of the threaded part is held at the middle part in the axial direction of the nut in the square-shaped nut housing and is screwed into the threaded part. A cover made of an elastic material having a hole and prevented from rotating by the nut housing is provided directly at both ends of the nut in the axial direction, and a stopper plate is attached to the nut housing to prevent the covers from moving in the axial direction. A dustproof device for a screw feed mechanism for moving automobile seats, which is characterized by: