Slide rail

Abstract

To provide a slide rail having a floating function of a nut having a function moved by a screw, in the slide rail having a mechanism for moving an upper rail by using the screw.SOLUTION: A slide rail 100 of the present invention includes an upper rail 10 to which a vehicle seat is attached, a lower rail 20 that guides the upper rail so as to be slidable back and forth, and a screw mechanism 30 that moves the upper rail back and forth, the screw mechanism 30 including a threaded screw 33, a gear unit 31 that drives the screw, a floating nut 35 screwed to the screw, and a shoulder bolt 40 that fixes the floating nut to the lower rail from a bottom surface side of the lower rail via the lower rail, wherein the shoulder bolt is provided so as to be movable up and down with respect to the lower rail.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a slide rail. [Background technology]

[0002] A slide rail equipped with a mechanism for moving an electric vehicle seat forward and backward has a structure that includes a round bar-shaped feed screw, a gear unit that transmits driving force from an electric motor to the feed screw, a nut threaded onto the feed screw, and two holders that attach and support the nut on the bottom surface of the lower rail (Patent Document 1).

[0003] The feed screw is formed with a screw shaft length that is shorter than the rail length (front-to-back length) of the upper rail, but close to the rail length of the upper rail. The feed screw extends axially along the sliding direction of the upper rail, and after being threaded through a nut, both ends of the feed screw are supported by L-shaped brackets so as to be axially rotatable, and the feed screw is attached to the bottom of the upper surface of the upper rail.

[0004] In the slide rail described above, the feed screw is supported by nuts fixed to two holders attached to the bottom of the lower rail, so there is no floating mechanism for the feed screw and it cannot move up and down. As a result, it is not possible to absorb the vertical vibrations caused by the rotation of the feed screw. This has led to problems such as an inability to rotate smoothly and noise generation.

[0005] To solve this problem, a system has been developed in which the fixed bracket and nut are sandwiched between a damper, allowing the nut to float up and down. However, this floating structure requires the installation of a fixed bracket, nut, and damper, which results in a large size, poor layout flexibility, and high costs. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-34214 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of these problems, and an object of the present invention is to provide a slide rail having a mechanism for moving an upper rail using a screw, which ensures the floating function of the nut that is moved by the screw, and which provides the floating function of the nut on the bottom surface of the lower rail rather than on the top surface of the lower rail, thereby allowing the screw having a feed screw function to float up and down in a small layout without using a bracket. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention employs the following means.

[0009] The slide rail according to the present invention comprises: an upper rail to which a vehicle seat is attached; a lower rail that guides the upper rail so that the upper rail can slide forward and backward; a screw mechanism for moving the upper rail back and forth, the screw mechanism including: a screw having a thread; a gear unit for driving the screw; a floating nut threaded onto the screw; and a shoulder bolt for fixing the floating nut to the lower rail from a bottom surface side of the lower rail via the lower rail; The stepped bolt is characterized in that it is provided so as to be movable up and down relative to the lower rail.

[0010] According to the slide rail of the present invention, by directly attaching the floating nut to the lower rail via the stepped bolt, the floating nut is firmly fixed by tightening the stepped bolt, while the stepped portion of the stepped bolt is movable up and down relative to the lower rail, allowing the floating nut to float up and down in accordance with the up and down vibration caused by the rotation of the screw. This makes it possible to achieve up and down floating in a small layout at low cost without using a damper or bracket, allowing the screw to rotate smoothly.

[0011] In addition, in the slide rail according to the present invention, two or more stepped bolts may be provided at the front and rear. By providing two or more stepped bolts at the front and rear, the floating nut is prevented from tilting back and forth like a seesaw, and twisting of the screw during rotation can be suppressed, allowing the screw to rotate smoothly.

[0012] Furthermore, in the slide rail according to the present invention, the vertical movement distance of the stepped bolt may be 1.0 mm to 2.0 mm. By setting this distance, the floating distance required for smooth rotation can be secured, and it is possible to prevent the screw from moving too far, causing vibration or impeding smooth rotation.

[0013] Furthermore, the slide rail according to the present invention may be characterized in that a sliding member is provided in the gap between the stepped bolt and a through-hole provided in the lower rail through which the stepped bolt passes. The sliding member may be made of a resin-coated metal. By providing the sliding member, vertical floating movement can be made smoother and horizontal rattle and small vertical vibrations can be prevented. [Effects of the Invention]

[0014] According to the slide rail of the present invention, it is possible to provide a slide rail with a floating function that allows a screw having a feed screw function to float up and down, with a small layout and low cost. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a slide rail 100 according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the slide rail 100 according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the slide rail 100 according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiment and drawings described below exemplify a part of the embodiment of the present invention and are not intended to be limiting to these configurations. Corresponding components in each drawing are denoted by the same or similar reference numerals. Note that in the present invention, "up and down" and "front and rear" refer to the directions shown in FIG. 1, and "front" refers to the direction in which the vehicle seat is moved forward.

[0017] The slide rail 100 according to this embodiment supports a vehicle seat (not shown) so that it can slide in the front-rear direction, and is attached to a vehicle floor (not shown) for use. As shown in Fig. 1, the slide rail 100 according to this embodiment mainly includes an upper rail 10 to which the vehicle seat is attached, a lower rail 20 that guides the upper rail 10 so that it can slide in the front-rear direction, and a screw mechanism 30 (see Fig. 2) that moves the upper rail 10 back and forth.

[0018] The upper rails 10 are primarily components to which a vehicle seat is attached and which move back and forth relative to the lower rails 20, thereby moving the vehicle seat back and forth.

[0019] The lower rail 20 is formed in the shape of a long rail, and as shown in Fig. 1, it guides the upper rail 10 so that it can slide. Various configurations have been proposed for the upper rail 10 and the lower rail 20, and an appropriate configuration can be selected and used depending on the intended use. The bottom surface of the lower rail 20 is provided with a through hole 13 for passing a shoulder bolt 40, which will be described later, therethrough.

[0020] The screw mechanism 30 mainly comprises a gear unit 31, a screw 33 that rotates by power transmitted from the gear unit 31, a floating nut 35 that threads onto the screw 33, and a stepped bolt 40 that fixes the floating nut 35 via the lower rail 20 from the bottom side of the lower rail 20.

[0021] The gear unit 31 is a component that receives power from a motor that is rotated by a power source and rotates the screw 33 around its longitudinal center as an axis, and the screw 33 can be rotated forward or backward by operating a switch provided in the driver's seat, passenger seat, etc. The gear configuration is not particularly limited, and any known gear unit can be appropriately selected and applied.

[0022] The screw 33 is formed in the shape of a long round rod, and is externally threaded (not shown in the figure) except at both ends. The front end or the vicinity of the front end of the screw 33 is linked to the gear unit 31 described above, and rotates by receiving power from the gear unit 31. Mounting brackets 33a for attaching the upper rail 10 are provided on the front and rear of the screw 33, and the upper rail 10 is attached via these mounting brackets 33a.

[0023] The floating nut 35 is a metal member having a horizontal internal thread (not shown in the figure) that screws into the threads of the screw 33. Furthermore, as shown in FIG. 3 , the floating nut 35 is fixed to the bottom side of the lower rail 20 by a shoulder bolt 40 via the through-hole 13, and the floating nut 35 cannot move in the fore-and-aft direction. When the screw 33 rotates, the relative horizontal positions of the floating nut 35 and the screw 33 change. However, since the floating nut 35 cannot move fore-and-aft, the screw 33 moves fore-and-aft. This also moves the fore-and-aft position of the mounting bracket 33a attached to the screw 33, and therefore the upper rail 10 attached to the mounting bracket 33a, and thus the vehicle seat attached to this upper rail 10, can be moved fore-and-aft.

[0024] The shoulder bolt 40 has a threaded portion 41 and an unthreaded cylindrical portion 42 having an outer diameter larger than that of the threaded portion 41, which is disposed between the threaded portion 41 and a head portion 43. As shown in the enlarged view of FIG. 3 , the length α of the cylindrical portion 42 is set to provide a gap (gaps β+γ formed both above and below the lower rail 20) so that the floating nut 35 can move up and down on the bottom surface of the lower rail 20 with the floating nut 35 attached. Furthermore, it is preferable that the gaps be formed both above and below the bottom plate of the lower rail 20 when the screw 33 is stationary and not powered. This allows for the screw 33 to accommodate runout in both the vertical and horizontal directions. This allows the shoulder bolt 40 to move up and down, allowing the floating nut 35 to float up and down, ensuring smooth rotation of the screw 33. The screw 33 is long, and due to the load imposed by the vehicle seat above it and component variations, vibration occurs during rotation. If the floating nut 35 were fixed so that it could not move, this vibration could not be absorbed, hindering smooth rotation and generating noise. However, the floating nut 35 of the present invention is movable up and down, so it can absorb this vibration and achieve smooth rotation. Furthermore, the total gap β+γ is preferably 1.5 mm to 2.5 mm, more preferably 1.0 mm to 2.0 mm. By setting this range, vibration caused by the rotation of the screw 33 can be absorbed. Since excessive vibration would actually hinder rotation, vibration can be limited within a certain range to ensure smooth rotation. Preferably, two or more shoulder bolts 40 are provided, one at the front and one at the back. Providing two shoulder bolts, one at the front and one at the back, prevents the floating nut 35 from tilting forward and backward, causing a seesaw-like movement, and prevents twisting of the screw 33.

[0025] Furthermore, a sliding member 60 may be provided between the stepped bolt 40 and the through hole 13 of the lower rail 20 to improve the sliding properties of the stepped bolt 40. The sliding member 60 is formed in a pulley shape so that the bottom and top surfaces of the lower rail 20 can be sandwiched between the sliding member 60 and the lower rail 20. This sliding member 60 is preferably made of metal coated with a resin that has high sliding properties, such as ultra-high molecular weight polyethylene, polyester, or nylon. The use of such a sliding member 60 allows the stepped bolt 40 to move smoothly up and down, prevents rattling of the stepped bolt 40, and reduces noise.

[0026] According to the slide rail 100 manufactured as described above, the floating nut 35 is moved up and down using the movable shoulder bolt 40, which eliminates the need for a fixing bracket or damper as in the past, thereby contributing to cost reduction. In addition, since the floating structure is provided on the lower rail side, there is an advantage that only a small space is required for layout.

[0027] The present invention is not limited to the above-described embodiment, and can be embodied in various forms as long as they fall within the technical scope of the present invention. [Industrial Applicability]

[0028] As shown in the above-described embodiment, the present invention is industrially applicable as a slide rail for mounting an automobile seat. [Explanation of symbols]

[0029] 10...upper rail, 100...slide rail, 13...through hole, 20...lower rail, 30...screw mechanism, 31...gear unit, 33...screw, 33a...mounting bracket, 35...floating nut, 40...shoulder bolt, 41...threaded portion, 42...cylindrical portion, 43...head, 60...sliding member, 100...slide rail

Claims

1. an upper rail to which a vehicle seat is attached; A lower rail guides the upper rail so that it can slide back and forth, a screw mechanism for moving the upper rail back and forth, the screw mechanism including a threaded screw, a gear unit for driving the screw, a floating nut threaded onto the screw, and a shoulder bolt for fixing the floating nut to the lower rail from the bottom side of the lower rail via the lower rail; The slide rail is characterized in that the stepped bolt is provided so as to be movable up and down relative to the lower rail.

2. 2. The slide rail according to claim 1, wherein two or more of the stepped bolts are provided at the front and rear.

3. 2. The slide rail according to claim 1, wherein the vertical movement distance of the stepped bolt is 1.0 mm to 2.0 mm.

4. 2. The slide rail according to claim 1, further comprising a sliding member disposed in a gap between the stepped bolt and a through-hole provided in the lower rail through which the stepped bolt passes.

5. 5. The slide rail according to claim 4, wherein the sliding member is made of a metal coated with a resin.

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