JP7538486B2 - Electric seat slide device - Google Patents

Description

The present invention relates to an electric seat sliding device for a vehicle, for example.

Conventional electric seat sliding devices for vehicles are known from the following patent documents 1 and 2.

The electric seat sliding device described in Patent Document 1 includes a pair of lower rails that are fixed to the vehicle floor along the front-rear direction of the vehicle body, a pair of upper rails that are slidably fitted to each of the lower rails along the longitudinal direction and connected to the vehicle seat, a pair of screw shafts that are arranged along the internal longitudinal direction of each of the upper rails and have male threads formed on their outer peripheries, a pair of nut members that are fixed at predetermined positions inside each of the lower rails and have female threaded holes into which the screw shafts are screwed, and a gear box that houses a gear mechanism that reduces the rotational speed of an electric motor to rotate and drive the screw shafts.

The system also has a long bracket that spans the left and right upper rails. This long bracket is designed to hold the electric motor and gearbox. In addition, protective covers are attached to the long bracket to cover the front and bottom of the electric motor and each gearbox.

The electric seat sliding device described in Patent Document 2 has a pair of openings formed in the left and right upper rails for mounting a pair of gear boxes, one of which is closed by a motor fixing bracket for mounting a motor. A bridging bracket is provided between the reinforcing bracket provided on the other upper rail and the motor fixing bracket, bridging the two brackets.

JP 2010-052495 A JP 2015-003590 A

However, the protective cover described in Patent Document 1 and the bridging bracket described in Patent Document 2 are both attached to the long bracket or upper rail using a fitting method that utilizes the flexural deformation of the bracket itself. These assembly operations are performed from above and below, utilizing the flexural deformation, which makes the assembly operation difficult and reduces the efficiency of the installation work.

The present invention was devised in consideration of the technical problems of the conventional technology, and one of its objectives is to provide an electric seat slide device that improves the efficiency of assembly work by allowing the protective cover to be assembled with a single touch to the motor housing and the first and second cylindrical parts of the gearbox.

As one aspect of the present invention, there is provided an electric seat slide device having a pair of left and right rail assemblies arranged along a front-rear direction of a vehicle body ,
The rail assembly includes:
A pair of lower rails fixed to a vehicle floor;
a pair of upper rails slidably attached to the pair of lower rails and attached to a vehicle seat;
a pair of screw shafts rotatably disposed between the upper rails and the lower rails, the pair of screw shafts each having a male thread formed on an outer periphery thereof;
a pair of nut members fixed to the lower rails and having female threaded holes into which the male threads of the screw shafts are screwed;
a pair of gear boxes fixed to the upper rails and including gear mechanisms for rotating the screw shafts;
a transmission member that connects an output shaft of an electric motor disposed between the pair of upper rails and an input shaft of at least one of the gear mechanisms;
a motor side holding member provided at one end of a cylindrical motor housing of the electric motor on the one gear box side, the motor side holding member having a first cylindrical portion into which one axial end portion of the transmission member on the one gear box side can be inserted, and a rotation prevention portion protruding in a radial direction from an outer circumferential surface of the first cylindrical portion ;
a gear side holding member provided at an upper end of the one of the gear boxes, the gear side holding member having a second cylindrical portion that faces the first cylindrical portion in the axial direction and into which the other axial end portion of the transmission member can be inserted;
a protective cover disposed between the motor side holding member and the gear side holding member, covering the one gear box, the gear side holding member, the first cylindrical portion, and the transmission member from above and having an open bottom surface;
Equipped with
The protective cover is
an insertion hole provided along the axial direction in one end portion of the transmission member that is on the motor-side holding member side in the axial direction, into which the first cylindrical portion can be inserted from the axial direction; and a notched groove provided on an inner circumferential surface of the insertion hole, into which the anti-rotation portion can be engaged from the axial direction,
an upper wall portion provided at the other end portion on the one gear box side in the axial direction and covering an upper portion of the one gear box; and a locking claw provided downward from the upper wall portion and capable of elastically locking from above into a locking recess provided in the one gear box.
The present invention is characterized by the following features.

The present invention makes it easier to assemble protective covers onto gearboxes and other components, improving the efficiency of the assembly process.

1 is a perspective view showing a rail assembly used in an embodiment of an electric seat slide device according to the present invention; FIG. 2 is an exploded perspective view showing one side of a rail assembly according to an embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of a basic component member used in the present embodiment. 1 is a perspective view showing a state in which a protective cover is attached to a rail assembly used in the present embodiment. FIG. FIG. 2 is a perspective view of a protective cover used in the present embodiment. 6 is a cross-sectional view taken along line AA in FIG. 5. FIG. 1 is a perspective view showing a state in which the protective cover used in the present embodiment is about to be placed over a transmission member and the like from above. FIG. FIG. 9 is a view taken along the arrow B in FIG. 8 . 1A and 1B show a state in which one end of a protective cover used in this embodiment is being assembled to a first cylindrical portion, in which FIG. 1A and 1B show a state after one end of the protective cover has been assembled and then the other end of the protective cover has been assembled to one of the gear boxes, where FIG.

Below, an embodiment of the electric seat slide device according to the present invention used in a vehicle will be described in detail with reference to the drawings.

Figure 1 is a perspective view showing a rail assembly used in an embodiment of an electric seat slide device according to the present invention, Figure 2 is an exploded perspective view showing one side of a rail assembly used in an embodiment of the present invention, and Figure 3 is a vertical cross-sectional view of the basic components used in this embodiment.

In this specification, the "up-down direction" refers to the up-down direction when the electric seat slide device is fixed to the floor surface of the vehicle body, and is the direction perpendicular to the floor surface of the vehicle body, i.e., the height direction of the vehicle body. In addition, in this specification, the "front-rear direction" refers to the front-rear direction of the vehicle body to which the electric seat slide device is fixed, as indicated by the arrow in Figure 1.

As shown in Figures 1 to 3, the electric seat slide device has a pair of rail assemblies arranged on both the left and right sides of the vehicle seat along the front-rear direction of the vehicle body.

This rail assembly includes a pair of lower rails 1 made of metal arranged along the front-rear direction on the floor of the vehicle (not shown), a pair of upper rails 2 made of metal slidably attached to each lower rail 1 along the longitudinal direction of the lower rail, a pair of screw shafts 3 which are metal rod-shaped members rotatably supported inside each upper rail 2, a pair of first and second gear boxes 4, 5 equipped with a gear mechanism which engages with a serration portion 32 (described later) provided at the front end of each screw shaft 3 to rotate and drive each screw shaft 3, an electric motor 6 arranged between both upper rails 2 and which rotates and drives the gear mechanisms provided inside the first and second gear boxes 4, 5, respectively, via transmission members 8, 16, a nut member 7 fixed to each lower rail 1 and having a female screw hole 40 into which each screw shaft 3 is screwed (engaged), and a plurality of slide guide members (not shown) which reduce frictional resistance when each upper rail 2 slides inside each lower rail 1 when a load in the front-rear direction acts on each upper rail 2.

The assemblies, each of which incorporates the upper rails 2 and the gearboxes 4, 5 into each lower rail 1, are arranged in a left-right pair between the vehicle seat (not shown) and the floor, parallel to each other along the fore-and-aft direction of the vehicle.

As shown in Figures 1 and 2, each lower rail 1 has a lower rail bottom wall 11 fixed to the floor surface of the vehicle body, a pair of lower rail outer walls 12 on either side of the lower rail bottom wall 11, a lower rail body 13 with a U-shaped cross section that is open at the top, a pair of lower rail upper walls 14 that extend inward from the tips of the lower rail outer walls 12, and a pair of lower rail inner walls 15 that extend from the tips of the lower rail upper walls 14 toward the lower rail bottom wall 11.

The distance between the pair of opposing lower rail inner walls 15 is set so that the upper rail 2 housed in the lower rail 1 can slide.

Each lower rail 1 is fixed to the vehicle floor at two points, the front and rear, in the longitudinal direction via leg brackets 20a and 20b. The leg brackets 20a and 20b are fixed to the lower rail bottom wall 11 by rivets.

1 and 2, the upper rail 2 has an upper rail main body 23 with a U-shaped cross section that is open at the bottom and includes an upper rail top wall 21 that is fixed to the back side of the seat and a pair of upper rail side walls 22 on either side of the upper rail top wall 21, and upper rail bent walls 24 that extend outward and upward from the tip of each upper rail side wall 22 while bending back and forth. A vehicle seat is attached to the upper rail 2 via bolts (not shown) that are inserted from below into a plurality of bolt insertion holes 21a formed in the upper rail top wall 21.

When the upper rail 2 is attached to the lower rail 1, the tip of each upper rail bent wall 24 fits between the lower rail outer wall 12 and the lower rail inner wall 15. In other words, the tip of each upper rail bent wall 24 overlaps with the lower rail inner wall 15.

As shown in FIG. 2, the upper rail 2 has two slits 25 of a predetermined width formed in the upper rail top wall 21 and upper rail side wall 22 at the front end 2a and rear end 2b for positioning and fixing two reinforcing plates 27, one in front and one in back. Each slit 25 is formed in the upper rail top wall 21 and side wall 22, and engages with each protrusion provided on the top surface and both side surfaces of the reinforcing plate 27 to crimp and fix each reinforcing plate 27 to the upper rail 2. Each reinforcing plate 27 has a through hole 27a formed in the center through which the screw shaft 3 is rotatably inserted.

Each screw shaft 3 is disposed between a pair of upper rail side walls 22 of the upper rail body 23. The screw shaft 3 has a screw shaft body 31 that passes through the nut member 7, a serration portion 32 provided at the front end to which the first and second gear boxes 4 and 5 are attached, and a small diameter shaft portion 33 provided at the rear end that is rotatably supported by an end cap 34 attached to the rear end face of the upper rail 2.

The screw shaft body 31 has a male thread 31a formed on its outer surface that screws into and meshes with the female threaded hole 40 of the nut member 7, which will be described later.

The serration portion 32 is provided at the front end of the screw shaft 3 on the vehicle front side, and is formed with a smaller diameter than the screw shaft body 31 so as not to interfere with the female threaded hole 40 of the nut member 7 during assembly. The serration portion 32 penetrates each gear box 4, and male serration teeth that engage with the worm wheel 43 described later are formed on the outer circumferential surface.

The small diameter shaft portion 33 is provided at the rear end of the screw shaft 3 and is rotatably supported within the cylindrical portion 34a of the end cap 34 via a stopper member (press-fit nut) 28. The small diameter shaft portion 33 is formed in a cylindrical shape with a smaller diameter than the screw shaft body 31 so as not to interfere with the female threaded hole 40 of the nut member 7.

The screw shaft 3 is prevented from slipping out rearward by a nut 35 screwed onto the threaded portion 32a at the tip of the serration portion 32. This nut 35 clamps the worm wheel 43 (described later) of the gear box 4 in the axial direction of the screw shaft via a washer 36 that faces the gear box 4.

Each screw shaft 3 and each nut member 7 constitute a screw mechanism that moves each upper rail 2 axially relative to each lower rail 1.

As shown in Figures 1 to 3, the first and second gearboxes 4, 5 are formed as boxes that can be separated in the left and right direction, for example from a zinc alloy material, and the respective dividing surfaces are aligned and joined by pin crimping.

In Fig. 1, the first gear box 4 on the left side has a second tubular portion 9, which is a gear-side retaining member, provided on the inner surface of the box body on the electric motor 6 side and protruding toward the electric motor 6. As shown in Fig. 3, this second tubular portion 9 is formed in an elongated cylindrical shape and is provided integrally with the box body, and has an insertion hole 9a formed therethrough in the internal axial direction into which one end 8c of a flexible shaft 8a (described later) of the transmission member 8 is inserted. In addition, the second tubular portion 9 has a large diameter hole 9b of a predetermined length formed on the inner peripheral surface on the axial opening side of one end of the insertion hole 9a into which one end of an outer tube 8b (described later) of the transmission member 8 is inserted and retained.

As shown in Figures 1 and 2, the first gear box 4 has a pair of locking recesses 4a, 4a at the top of both side walls, which are engaged from above by a pair of locking claws 58 provided at the other end 53 of the protective cover 50, which will be described later.

In Fig. 1, the second gear box 5 on the right side is provided with a third cylindrical portion 10 protruding toward the electric motor 6 on the inner surface of the box body on the electric motor 6 side, as shown in Fig. 2 and Fig. 3. The third cylindrical portion 10 is formed in an elongated cylindrical shape and is provided integrally with the box body, and an insertion hole 10a through which the second transmission member 16 is inserted in the internal axial direction is formed. The third cylindrical portion 10 is also provided integrally with a large-diameter cylindrical retaining portion 10b at the tip end on the electric motor 6 side. This retaining portion 10b is fitted axially into a cylindrical portion 6d (described later) of the motor housing 6a of the electric motor 6, and is fixed to the motor housing 6a by two bolts 17 via a pair of brackets integrally formed on the outer periphery. The second transmission member 16 is formed in the shape of a rod shaft, with one axial end 16a inserted into a special hole provided in the input shaft 42a of the worm 42 that constitutes the gear mechanism and connected so as to be rotatable together, and the other axial end 16b connected axially to one output shaft 6c of the electric motor 6.

The first and second gear boxes 4, 5 each have a built-in gear mechanism and are crimped and fixed to the front end 2a of each side wall 22 of the upper rail 2 by pin members 46 shown in Figure 2.

As shown in FIG. 3, each gear mechanism has a worm gear consisting of a resin worm 42 and a resin worm wheel 43 that meshes with it.

Each worm 42 is driven to rotate in the forward or reverse direction by the electric motor 6 via the first and second transmission members 8 and 16. When each worm 42 is driven to rotate in the forward or reverse direction, each worm wheel 43 meshing with it rotates.

The worm wheel 43 has a female serration portion 44 on the inner peripheral surface of the central hole that fits into the male serrations of the serration portion 32 of the screw shaft 3.

Therefore, each screw shaft 3 rotates while being supported by the upper rail 2 as each worm wheel 43 rotates with the rotation of each worm 42. Since each screw shaft 3 is screwed into a nut member 7 fixed to the lower rail 1, when the worm wheel 43 rotates, the upper rail 2 slides forward or backward relative to the lower rail 1.

The electric motor 6 has a general structure, and as shown in FIG. 3, has a motor housing 6a made of a metal material that houses electrical components such as a stator and rotor, and a pair of output shafts 6b, 6c made of a metal material that extend in the left-right axial direction from the center of the rotor built into the motor housing 6a.

As shown in Figs. 1 and 3, the motor housing 6a is formed in a cylindrical shape extending in the direction of both upper rails 2, 2, and a first tubular portion 18 is attached to one end of the motor housing 6a on the side of the first gear box 4. The first tubular portion 18 is formed integrally with the motor housing 6a using a resin material to cover a part of the motor housing 6a, and an insertion hole 18a is formed through the motor housing 6a in the internal axial direction, into which the other end 8d of the flexible shaft 8a of the first transmission member 8 and the other end of the outer tube 8b are inserted. The first tubular portion 18 is integrally provided with a large diameter cylindrical portion 18b with a bottom that is fitted and fixed to the outer periphery of one end of the motor housing 6a. In addition, as shown in Fig. 1, the first tubular portion 18 has a rotation stopper portion 19 that protrudes in the radial direction along the axial direction at a predetermined position in the circumferential direction of the outer circumferential surface. The rotation stopper portion 19 is formed in an elongated plate shape and extends from the edge of the large diameter cylindrical portion 18b on the first gear box 4 side along the axial direction of the first tubular portion 18 toward the first gear box 4. The first cylindrical portion 18 and the anti-rotation portion 19 form the motor side holding member.

The electric motor 6 rotates with the gear mechanisms (worm 42, worm wheel 43) of the first and second gear boxes 4 and 5, and can adjust the position of the vehicle seat fixed to the upper rail 2 along the longitudinal direction of the lower rail 1 (front-rear direction of the vehicle) via each screw shaft 3.

As shown in Figures 1 and 3(a), the first transmission member 8 has a flexible shaft 8a and an outer tube 8b that covers the outer surface of the flexible shaft 8a.

The flexible shaft 8a is formed to be flexible and deformable, and one end 8c protruding from the outer tube 8b is inserted (connected) into the hole of the input shaft 42a of one worm 42 from inside the second cylindrical portion 9. The other end 8d protruding from the outer tube 8b is inserted (connected) into the hole of the other output shaft 6b of the electric motor 6 from inside the first cylindrical portion 18. The hole of the input shaft 42a of the worm 42 of the first gear box 4 and the hole of one output shaft 6b of the electric motor 6 are each formed to have a non-circular (almost square) cross-sectional shape. On the other hand, as shown in Figures 3(b) and (c), one end 8c and the other end 8d of the flexible shaft 8a are formed to have a non-circular (almost square) cross-sectional shape that matches the cross-sectional shape of each hole, and after being inserted while matching the shape with both holes, free relative rotation with each hole is restricted. This allows the rotational force of the electric motor 6 to be efficiently transmitted to one of the screw shafts 31 via the gear mechanism (worm 42, worm wheel 43) of the first gear box 4 via the flexible shaft 8a.

The outer tube 8b is made of a flexible synthetic resin material, and as described above, one end is inserted and fixed into the large diameter hole 9b of the second cylindrical portion 9, and the other end is inserted and fixed into the first insertion hole 18a of the first cylindrical portion 18.

As shown in FIG. 2, the nut member 7 has a bracket 7a and a nut component 7b that is held inside the bracket 7a together with an elastic member 7c.

The bracket 7a is bent into an ohm shape and is positioned and fixed to the upper surface of the lower rail bottom wall 11 of the lower rail 1 by a pair of rivets 45 inserted into insertion holes formed in a pair of bracket pieces 38 extending in the fore-aft direction of the vehicle body. The bracket 7a has a pair of rising pieces 39 rising from the opposing edges of both bracket pieces 38, through which a shaft insertion hole 39a through which the screw shaft 3 is rotatably inserted is formed.

The nut component 7b is formed in a block shape from metal material, and has a female threaded hole 40 formed therethrough in the internal axial direction (the front-to-rear direction of the vehicle body) into which the male thread 31a of the screw shaft 3 screws (interlocks).

The elastic member 7c is made, for example, by bending a rubber material into a U-shape, and is held inside the bracket 7a while fitting into the nut component 7b. A pair of insertion holes 41 are formed through the pair of rising pieces, into which the screw shaft 3 is inserted.

The slide guide member (not shown) is disposed between the lower rail outer wall 12 and the upper rail bent wall 24. The slide guide member is a known structure in which a number of steel balls are held above and below a retainer, and is provided at two locations, one at the front and one at the back, in the range where the lower rail 1 and the upper rail 2 overlap in the longitudinal direction.

The maximum forward/backward movement position of each upper rail 2 is restricted by abutment of a pair of front and rear stopper pieces 11a, 11b cut and raised at the front and rear positions of the lower rail bottom wall 11 of the lower rail 1 by a stopper portion (not shown) provided on each upper rail 2.

Figure 4 is a perspective view showing the state in which the protective cover is attached to the rail assembly used in this embodiment, Figure 5 is a perspective view of the protective cover used in this embodiment, Figure 6 is a cross-sectional view taken along line A-A in Figure 5, and Figure 7 is a bottom view of the protective cover. Figure 8 is a perspective view showing the state in which the protective cover is about to be placed over the transmission member from above, and Figure 9 is a view taken along arrow B in Figure 8.

As shown in FIG. 4, a protective cover 50 is disposed between the first gearbox 4 and the first cylindrical portion 18 on the electric motor 6 side, covering the first gearbox 4, the second cylindrical portion 9, the first cylindrical portion 18, and the entire transmission member 8 from above in the vertical direction.

As shown in Figs. 4 to 7, the protective cover 50 is made of synthetic resin and is formed in an inverted U-shape with a substantially rectangular cross section that is open at the bottom, and extends from the first gearbox 4 to the first tubular portion 18. That is, the protective cover 50 has a flat upper wall portion 50a and two side walls 50b, 50b extending downward from both front and rear ends of the upper wall portion 50a. The protective cover 50 formed by these walls 50a, 50b, 50b has a central portion 51 that is long in the longitudinal direction, one end portion 52 that extends from the edge of the central portion 51 on the first tubular portion 18 side and has a cross-sectional shape larger than that of the central portion 51, and the other end portion 53 that extends from the edge of the central portion 51 on the first gearbox 4 side and has a cross-sectional shape larger than that of the central portion 51. The central portion 51 and both ends 52, 53 are connected by inclined connecting walls 54, 54.

As shown in FIG. 7, both side walls 50b, 50b of the protective cover 50(c) are made up of inner and outer double walls with a certain gap between them, and multiple reinforcing ribs 50c are provided at predetermined positions in the longitudinal direction of the inner and outer double walls.

The central portion 51 has three rectangular holes 50d formed vertically at three locations at regular intervals in the longitudinal direction in the upper wall portion 50a. In addition, at the lower portion where each rectangular hole 50d is located on the inner wall of each of the side wall portions 50b, 50b, a pair of holding pieces 55 protrude inward and facing each other. Each of these facing holding pieces 55 has an elastic force that allows it to bend inward and outward, and when the protective cover 50 is assembled, it holds the outer surface of the outer tube 8b in a clamped state by its elastic force.

As shown in Figs. 5 to 7, the one end 52 is formed in a box shape with an open bottom, a thick front end wall 52a is formed with a recess inward, and a first insertion hole 56 into which the first cylindrical part 18 can be inserted is provided inside, which is made of multiple rib-shaped wall pieces. The inner diameter of the inner peripheral surface of this first insertion hole 56 is gradually reduced from the tip end along the internal axial direction, and is formed in a tapered shape with a reduced diameter toward the back. In addition, the first insertion hole 56 is formed in an arch shape by cutting out the lower parts of the front end wall 52a and the next wall piece 52b inside it, and a first opening 56a is formed at the lower part of each. This first opening 56a is formed along the internal axial direction from the tip side of the open tip of the insertion hole 56, and the opening width W perpendicular to the axial direction is larger than the outer diameter of the outer tube 8b and smaller than the outer diameter of the first cylindrical part 18.

At a predetermined position on the inner peripheral surface of the first opening 56a, a rotation restriction groove 59, which is a notched groove into which the rotation prevention portion 19 of the first cylindrical portion 18 is inserted from the axial direction, is formed along the axial direction of the opening 56a. The rotation restriction groove 59 is formed at a location corresponding to the position where the rotation prevention portion 19 is positioned by previously rotating and fixing the first cylindrical portion 18 to a predetermined position relative to the motor housing 6a.

In this embodiment, one rotation restriction groove 59 is provided, but two may be provided at symmetrical positions (left and right symmetrical) based on the center line in the longitudinal direction. In this case, the same protective cover can be used even when the electric motors are arranged in opposite directions on the left and right rail assemblies, allowing for common use.

As shown in Figs. 5 and 9, the other end 53 is formed in a box shape with a cutout at the bottom, and is cut out in a stepped shape that gradually becomes lower from the rear end wall 53a toward the center portion 51. In addition, the other end 53 has a second insertion hole 57 into which the second cylindrical portion 9 can be inserted, inside a plurality of rib-shaped wall pieces. The entire portion, including this second insertion hole 57 and the first insertion hole 56, penetrates along the internal axial direction from the rear end 53a to the front end 52a, and is formed in an arch shape as a whole. In addition, the second insertion hole 57 is formed by cutting out the lower portions of the rear end wall 53a and each wall piece 53b, 53c to form a second opening 57a. In other words, this second opening 57a is formed in the entire lower portion of the second insertion hole 57, and the entire second insertion hole 57 is formed in an arch shape. In addition, the second opening 57a is formed so that the opening width W1 perpendicular to the axial direction is larger than the outer diameter of the second cylindrical portion 9.

7 and 9, a pair of locking claws 58 are integrally provided on the underside of the other end 53 near the rear end wall 53a of the upper wall portion 50a'. Both locking claws 58 are provided in a hanging state from the underside of the upper wall portion 50a' and are formed so as to be elastically deformable in the left-right direction (expansion/contraction direction) relative to each other. Both locking claws 58 have opposing inner surfaces formed in a protrusion shape and are elastically locked into both locking recesses 4a of the first gear box 4, thereby stably and reliably holding the other end 53 to the first gear box 4.
[Procedure for Assembling the Protective Cover of the Present Embodiment]
Next, the procedure for assembling the protective cover 50 in this embodiment will be described with reference to Figures 10 and 11. Figures 10(a) and 10(b) are explanatory diagrams showing a state in which one end 52 of the protective cover 50 is assembled to the electric motor 6 side, and Figures 11(a) and 11(b) are explanatory diagrams showing a state in which the other end 53 of the protective cover 50 is assembled to the first gear box 4 side after the one end 52 of the protective cover 50 has been assembled.

Each upper rail 2 is connected to the bottom of the vehicle seat in advance, and the first and second gear boxes 4, 5 and the electric motor 6 are attached between each lower rail 1 and each upper rail 2. As shown in FIG. 1, both ends 8c, 8d of the flexible shaft 8a of the transmission member 8 and both ends of the outer tube 8b are inserted and connected to the worm 42 and first cylindrical portion 18 of the second gear box 5, and the worm 42 and second cylindrical portion 9 of the first gear box 4, respectively.

In this state, first, hold the center portion 51 and the other end portion 53 of the protective cover 50 by hand, position it so as to cover the transmission member 8 from above, and fit the one end portion 52 to the first cylindrical portion 18 side. Specifically, as shown in Figures 8 and 10(a) and (b), cover the one end portion 52 side of the protective cover 50 from diagonally above toward the first cylindrical portion 18, fit the first opening 56a to the first cylindrical portion 18 from above, and push the protective cover 50 to the maximum toward the electric motor 6 while engaging the rotation prevention portion 19 from the axial direction into the rotation prevention groove 59. In other words, push the protective cover 50 to the maximum until the front end wall 52a of the one end portion 52 hits the tip wall of the large diameter cylindrical portion 18b. As a result, the protective cover 50 is positioned and held in the circumferential direction while the rotation prevention portion 19 prevents free rotation. Meanwhile, the first tube portion 18 is inserted into the first insertion hole 56 and is held in an embraced state by the edge of the first opening 56a.

In this state, the protective cover 50 is placed at an angle with the other end 53 above the first gear box 4, as shown in Figures 8 and 10(a) and (b).

From this state, the other end 53 (upper wall portion 50a') of the protective cover 50 is pressed downward in the vertical direction. Then, as shown in Figures 11(a) and (b), the second tubular portion 9 is fitted and held in the second insertion hole 57 via the second opening 57a. At the same time, the pair of locking claws 58 of the other end 53 elastically deform in an enlarged shape at the top of both sides of the first gear box 4 and enter each locking recess 4a, whereupon they deform in a reduced diameter and are locked by the elastic return force of each locking recess 4a.

As a result, the protective cover 50 covers the entire transmission member 8 while both ends 52, 53 are securely fitted and fixed to the first and second tubular portions 18, 9, and can be assembled with a single touch. As a result, the efficiency of the assembly work of the protective cover 50 is improved.

In particular, the first and second openings 56a, 57a are provided in the first and second insertion holes 56, 57 at one end 52 and the other end 53 of the protective cover 50, making it easier to assemble the protective cover to the first and second cylindrical portions 18, 9. In addition, the first insertion hole 56 is tapered, making it easier to insert the protective cover into the first cylindrical portion 18.

In this embodiment, compared to the structure of a conventional protective cover, it is possible to simply provide a pair of locking claws 58 at the other end 53 of the protective cover 50 and a locking recess 4a in the first gear box 4, thereby simplifying the structure and reducing costs.

Furthermore, the first tube portion 18 of the protective cover 50 is inserted and held in the axial direction in the first insertion hole 56 at one end 52, and at the other end 53, a pair of locking claws 58 are locked into a pair of locking recesses 4a, making it possible to hold the entire protective cover 50 stably and reliably.

When removing the protective cover 50, the other end 53 is pulled up to release the locking claw 58 from the locking recess 4a against the elastic force, and the protective cover 50 is then pulled out in the opposite direction to the electric motor 6, causing the first insertion hole 56 to come out of the first tubular portion 18, making it possible to easily remove the entire protective cover 50.

Furthermore, the protective cover 50 has two side walls 50b, 50b each with a double inner and outer structure, ensuring sufficient rigidity, and the double walls are joined by multiple ribs 50c, further increasing rigidity and improving durability.

As described above, when the protective cover 50 is placed over the transmission member 8, the outer tube 8b is held in a clamped state by the retaining pieces 55, 55, so that the transmission member 8 is stably held within the protective cover 50 via the outer tube 8b, and the retaining pieces 55, 55 are not visible from the outside, improving the appearance quality.

The present invention is not limited to the configuration of the above embodiment, and for example, a shaft other than a flexible shaft can be used as the transmission member. In addition, in this embodiment, the locking claw 58 of the protective cover 50 is locked into the locking recess of the gear box 4, but the locking recess may be provided on the upper rail 2 side for locking.

The electric seat slide device of the present invention can also be used in ships in addition to vehicles.

The electric seat slide device based on the embodiment described above may have the following configuration, for example.

In one embodiment, a pair of left and right rail assemblies are arranged on both the left and right sides of a vehicle seat along the front-rear direction of the vehicle body,
A pair of lower rails fixed to a vehicle floor;
a pair of upper rails slidably attached to the pair of lower rails and to which a vehicle seat is attached;
a pair of screw shafts rotatably disposed between the upper rails and the lower rails, the pair of screw shafts each having a male thread formed on an outer periphery thereof;
a pair of nut members fixed to the lower rails and having female threaded holes into which the male threads of the screw shafts are screwed;
a pair of gear boxes fixed to the upper rails and including gear mechanisms for rotating the screw shafts;
a transmission member that connects an output shaft of an electric motor disposed between the pair of upper rails and an input shaft of at least one of the gear mechanisms;
a motor side holding member provided at one end of a cylindrical motor housing of the electric motor on the one gear box side, the motor side holding member having a first cylindrical portion into which one axial end of the transmission member on the one gear box side can be inserted, and a rotation prevention portion protruding in a radial direction from an outer circumferential surface of the first cylindrical portion;
a gear side holding member provided at an upper end of the one of the gear boxes, the gear side holding member having a second cylindrical portion that faces the first cylindrical portion in the axial direction and into which the other axial end portion of the transmission member can be inserted;
a protective cover disposed between the motor side holding member and the gear side holding member, covering the one gear box, the gear side holding member, the first cylindrical portion, and the transmission member from above and having an open bottom surface;
Equipped with
The protective cover is
an insertion hole provided along the axial direction in one end portion of the transmission member that is on the motor-side holding member side in the axial direction, into which the first cylindrical portion can be inserted from the axial direction; and a notched groove provided on an inner circumferential surface of the insertion hole, into which the anti-rotation portion can be engaged from the axial direction,
an upper wall portion provided at the other end portion on the one gear box side in the axial direction and covering an upper portion of the one gear box; and a locking claw provided downward from the upper wall portion and capable of elastically locking from above into a locking recess provided in the one gear box.
It is equipped with:

According to this aspect of the invention, the protective cover is slid from one upper rail side to the other upper rail side, and the first tube portion is inserted into the insertion hole to a predetermined position while aligning the notch groove on one end side with the anti-rotation portion of the motor-side holding member. This positions and holds the one end side of the protective cover relative to the motor-side holding member. After that, when the other end (upper wall portion) of the protective cover, which is inclined upward, is pressed down, the locking claw on the upper wall portion elastically locks into the locking recess of one of the gear boxes.

This allows the protective cover to be attached to the side of the vehicle seat with a single touch, making the assembly process easier.

In addition, compared to conventional structures, the present invention can be achieved by simply providing a locking recess in one of the gear boxes, simplifying the structure and reducing costs.

More preferably, the transmission member includes a flexible shaft having non-circular cross-sectional shapes at both ends in the axial direction, the flexible shaft being inserted into connecting holes formed in the internal axial direction of each of the input shaft and the output shaft, and an outer tube covering the entire flexible shaft except for both ends, the both axial ends of the outer tube being inserted into the first cylindrical portion and the second cylindrical portion,
An opening portion that opens downward is formed on the underside of the open tip of the insertion hole on one end side of the protective cover,
the opening is formed such that an opening width perpendicular to the axial direction is larger than an outer diameter of the outer tube and smaller than an outer diameter of the first cylindrical portion,
The insertion hole is formed in a tapered shape such that the inside diameter gradually decreases from the opening at the tip end toward the inner axial direction.

According to this aspect of the invention, the flexible shaft and the outer tube are inserted into the first cylindrical portion on the motor housing side and the second cylindrical portion of one of the gearboxes, respectively, to connect them. After that, the protective cover is first placed over the outer tube from above, while aligning the opening of one end with both radially opposite sides of the first cylindrical portion from above, and inserting the first cylindrical portion into the insertion hole. Next, the other end (upper wall portion) of the protective cover is pushed downward to engage the locking claw with the locking recess, completing the assembly work. In particular, the provision of the opening and the tapered shape of the insertion hole make it easier to insert the first cylindrical portion.

More preferably, the protective cover has one side wall and the other side wall facing each other in the vehicle width direction, each formed as an inner and outer double wall, with a rib interposed between each of the inner and outer double walls, and each of the inner walls facing each other of the one side wall and the other side wall has a pair of retaining pieces that hold the outer tube in a clamped state.

According to this aspect of the invention, the protective cover has two side walls, each of which has a double inner and outer structure, ensuring sufficient rigidity, and the double inner and outer walls are joined by ribs, further increasing rigidity and improving durability.

In addition, when the protective cover is placed over the transmission member, the outer tube is held in a clamped state by each of the retaining pieces, so the transmission member is stably held within the protective cover via the outer tube, and the retaining pieces are not visible from the outside, improving the appearance quality.

1...Lower rail, 2...Upper rail, 3...Screw shaft, 4...First gear box, 5...Second gear box, 6...Electric motor, 6a...Motor housing, 6b...Output shaft, 6c...Output shaft, 7...Nut member, 8...Transmission member, 8a...Flexible shaft, 8b...Outer tube, 9...Second cylindrical portion (gear side holding member), 9a...Insertion hole, 18...First cylindrical portion (motor side holding member), 18a...Insertion hole, 18b...Large diameter cylindrical portion, 19...Rotation stopper, 31...Screw shaft main body, 31a...Male thread, 40...Female thread hole, 50...Protective cover, 50a...Upper wall portion, 50b...Both side wall portions, 51...Central portion, 52...One end portion, 53...Other end portion, 55...Holding piece, 56...First insertion hole, 56a...First opening, 57...Second insertion hole, 57a...Second opening, 59...Rotation restriction groove (notched groove).

Claims (3)

An electric seat slide device having a pair of left and right rail assemblies arranged along the front-rear direction of a vehicle body ,
The rail assembly includes:
A pair of lower rails fixed to a vehicle floor;
a pair of upper rails slidably attached to the pair of lower rails and attached to a vehicle seat;
a pair of screw shafts rotatably disposed between the upper rails and the lower rails, the pair of screw shafts each having a male thread formed on an outer periphery thereof;
a pair of nut members fixed to the lower rails and having female threaded holes into which the male threads of the screw shafts are screwed;
a pair of gear boxes fixed to the upper rails and including gear mechanisms for rotating the screw shafts;
a transmission member that connects an output shaft of an electric motor disposed between the pair of upper rails and an input shaft of at least one of the gear mechanisms;
a motor side holding member provided at one end of a cylindrical motor housing of the electric motor on the one gear box side, the motor side holding member having a first cylindrical portion into which one axial end portion of the transmission member on the one gear box side can be inserted, and a rotation prevention portion protruding in a radial direction from an outer circumferential surface of the first cylindrical portion ;
a gear side holding member provided at an upper end of the one of the gear boxes, the gear side holding member having a second cylindrical portion that faces the first cylindrical portion in the axial direction and into which the other axial end portion of the transmission member can be inserted;
a protective cover disposed between the motor side holding member and the gear side holding member, covering the one gear box, the gear side holding member, the first cylindrical portion, and the transmission member from above and having an open bottom surface;
Equipped with
The protective cover is
an insertion hole, into which the first cylindrical portion is inserted from the axial direction, that is provided along the axial direction in one end portion of the transmission member that is on the side of the motor-side holding member in the axial direction; and a notch groove, into which the anti-rotation portion is engaged from the axial direction, that is provided on an inner circumferential surface of the insertion hole,
an upper wall portion provided at the other end portion on the one gear box side in the axial direction and covering an upper portion of the one gear box; and a locking claw provided downward from the upper wall portion and capable of elastically locking from above into a locking recess provided in the one gear box.
An electric seat slide device comprising: The electric seat slide device according to claim 1,
The transmission member includes a flexible shaft having both axial ends with a non-circular cross-sectional shape and is inserted into a connecting hole formed in each of the input shaft and the output shaft in the axial direction, and an outer tube covering the entire flexible shaft except for both axial ends, and both axial ends of the outer tube are inserted into the first cylindrical portion and the second cylindrical portion, respectively.
An opening portion that opens downward is formed on the underside of the open tip of the insertion hole on one end side of the protective cover,
the opening is formed such that an opening width perpendicular to the axial direction is larger than an outer diameter of the outer tube and smaller than an outer diameter of the first cylindrical portion,
The electric seat slide device, wherein the insertion hole is formed in a tapered shape such that an inner diameter gradually decreases from an opening at a tip end toward an inner axial direction. The electric seat slide device according to claim 2,
The protective cover has one side wall and the other side wall facing each other in the vehicle width direction, each formed as an inner and outer double wall, a rib interposed between each of the inner and outer double walls, and a pair of retaining pieces on the opposing inner walls of the one side wall and the other side wall, which hold the outer tube in a clamped state.

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