JP3477768B2 - Seat reclining device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat reclining device. Conventionally, a seat reclining device of this type is disclosed in Japanese Patent Application Laid-Open No. 2-128707. This includes a lower arm fixed to the seat cushion, an upper arm fixed to the seat back, a shaft for rotatably supporting the upper arm on the lower arm, a slidable pole and a ratchet provided between the lower arm and the upper arm. A locking mechanism with
A lock release mechanism having a cam supported on a shaft and sliding the pole, wherein rotation of the upper arm with respect to the lower arm is restricted by maintaining engagement of the pawl and the ratchet by joining the pawl and the cam. Then, the upper arm is allowed to rotate with respect to the lower arm by releasing the engagement between the pawl and the ratchet by rotating the cam to release the connection between the cam and the pawl. Further, the cam is supported on the shaft by inserting a shaft having a predetermined diameter formed on the rotating shaft into a hole formed on the cam and having a diameter larger than the shaft so as to have a predetermined clearance. The cam is moved with respect to the shaft using the clearance so as to avoid poor joint between the cam and the pole due to a dimensional error of the pole and the cam. However, in the above-described conventional apparatus, the diameter of the hole is larger than the diameter of the shaft to form a clearance between the cam and the shaft. The movement of the cam with respect to the shaft is performed in the entire circumferential direction of the shaft, and depending on the direction of movement of the cam, the joint point between the cam and the pole is shifted from the normal position, that is, a sufficient joining margin can be secured. There was a risk of poor bonding. SUMMARY OF THE INVENTION Accordingly, it is a technical object of the present invention to prevent a defective joint due to a dimensional error between a pole and a cam, and to ensure a joint margin between a cam and a pole. . [0006] technical means taken in the present invention to solve the above technical problem Means for Solving the Problems] SUMMARY OF THE INVENTION [0007], the Po
The cam and the cam are joined, and the pawl and the ratchet mesh.
And Nimen width shaft portion having a first arcuate portion for connecting the first planar portion and a first planar portion of the pair is parallel to the sliding direction of the pole is formed in the shaft when the engagement, the cam And a pair of second flat portions slidingly contacting the first flat portion, and a second arc portion connecting the second flat portions and forming a predetermined clearance between the second flat portion and the first arc portion. And a two-sided width hole. According to the above technical means, the cam utilizes the clearance between the first and second arc portions and slides between the first and second flat portions. The contact allows the pole to move only in the sliding direction of the pole with respect to the shaft. Thank you
Poor joining due to dimensional errors of the pawl and the cam can be avoided, and the joining margin between the cam and the pawl can be ensured. Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, both arms 1 and 2 are attached to a lower arm 1 fixed to a seat cushion (not shown) and an upper arm 2 fixed to a seat back (not shown). The rotating shaft 3 is rotatably supported in a penetrating manner, and the upper arm 2 is rotatable about the rotating shaft 3 with respect to the lower arm 1. Supporting portion 1 of lower arm 1 and upper arm 2 to rotating shaft 3
The holes 1 and 12 are each formed in a half-punched direction in a direction facing each other, and a space A is formed between the lower arm 1 and the upper arm 2 by the half-punching. In this space A, a cam 41 constituting the lock release mechanism 4, a pawl 51 and a ratchet 52 constituting the lock mechanism 5 are arranged. The cam 41 is fixed to the rotary shaft 3 so as to rotate integrally with the rotary shaft 3, and the ratchet 52 is formed integrally with the upper arm 2 in a circular shape with the rotary shaft 3 as the center by utilizing half-opening of the upper arm 2. The pawl 51 is slidably disposed between the cam 41 and the ratchet 52 so as to be guided by the lower arm 1 and the upper arm 2, and can be joined to the cam 41 and mesh with the ratchet 52. The cam 41 and the pawl 51 are formed with a foot 41a and a cam surface 51a which can be engaged in the rotation direction. The connection between the pawl 51 and the cam 41 is performed by a projection 41b formed on the cam 41 and a cam-shaped rear surface 51b of the pawl 51. The mesh between the pawl 51 and the ratchet 52 is formed on the pawl 51. This is performed by the teeth 51c and the teeth 52a formed on the ratchet 52. The poles 51 are arranged symmetrically about the rotation axis 3 in pairs, and the cams 41
Are formed on the cam 41 as a pair in accordance with the arrangement of the pole 51. In the above-described configuration, the rotation of the upper arm 2 with respect to the lower arm 1 is restricted by joining the pawl 51 and the cam 41 to restrict the sliding of the pawl 51 and maintain the meshing of the pawl 51 and the ratchet 52. ing. In this state, when the rotating shaft 3 is rotated counterclockwise as shown in FIG. 1, the cam 41 rotates counterclockwise as shown in FIG. At the same time, the foot 41a and the cam surface 51a are engaged, and the pair of pawls 51 is slid toward the rotating shaft 3. As a result, the engagement between the pawl 51 and the ratchet 52 is released, and the rotation of the upper arm 2 with respect to the lower arm 1 is allowed. When the rotation shaft 3 is rotated in the reverse direction in a state where the rotation of the upper arm 2 with respect to the lower arm 1 is performed, the pawl 51 and the cam 41 are joined, and the pawl 51 slides in the opposite direction. Let me know. As a result, the ratchet 52 and the pawl 51 mesh with each other, and the rotation of the upper arm 2 with respect to the lower arm 1 is restricted. The above structure is disposed on both sides of the seat cushion and the seat back, and an operation handle (not shown) is provided at one end of the rotating shaft 3 in the outside direction of the seat (right end in FIG. 2). Are fixed, and both ends of the rotating shafts 3 in the sheet direction (the left ends in FIG. 2) are connected by connecting rods 31. A bush 6 is fixed to the lower arm 1 between the lower arm 1 and the rotary shaft 3 in order to ensure a smooth rotation operation of the rotary shaft 3. This bushyu 6
Is also used as a locking member for the spiral spring 9 that is disposed between the upper arm 2 and the lower arm 1 and that urges the lower arm 1 to rotate counterclockwise in FIG. . The support of the cam 41, which is the main part of the present invention, on the rotating shaft 3 will be described. As shown in FIG. 1 and FIG.
The two-plane width shaft portion 7 includes a pair of first flat portions 71 parallel to a line connecting the joining points of the pawls 51 and the cams 42 and a first circular arc portion 72 connecting the first flat surfaces 71. Are formed. The cam 42 has a pair of second flat portions 81 parallel to the first flat portion 71 and a first circular portion 72 which is co-centered with the first circular portion 72 connecting between the second flat portions 81.
A two-sided wide hole portion 8 formed of a second circular arc portion 82 having a larger diameter is formed. The two-plane width shaft portion 7 includes a first flat portion 71 and a second flat portion 81 in sliding contact with each other, and a first circular portion 72 and a second circular portion 8.
2 so that a predetermined clearance B is formed between
It is inserted into the two-sided wide hole portion 8. Thereby, the cam 41 is fixed so as to rotate integrally with the rotating shaft 3 (the cam 41 is supported by the rotating shaft 3). In the above-described configuration, if the cam 41 and the pawl 51 are clogged or loose due to a dimensional error or the like in the joint, the cam 41 becomes the first arc portion 72 and the second arc portion 8.
By using a clearance B between the rotation shaft 2 and the rotation shaft 2, the rotation shaft 3 is moved so as to cancel the clogging and the play. As a result, a poor connection between the cam 41 and the pole 51 due to a dimensional error or the like is eliminated. The movement of the cam 41 with respect to the rotating shaft 3 is restricted in the sliding direction of the pole 51 by the sliding contact between the first flat portion 71 and the second flat portion 82. Thus, the joining point between the pawl 51 and the cam 41 is not displaced by the movement of the cam 41, and the joining is always reliably made at the regular position. As a result, a sufficient joining margin between the pawl 41 and the cam 41 is reliably ensured. According to the present invention, the cam is supported on the shaft by inserting the two-surface wide shaft formed on the shaft into the two-surface wide hole formed on the cam. Utilizing the clearance between the first arc portion of the width shaft portion and the second arc portion of the width hole portion, the first flat portion of the width shaft portion and the second flat portion of the width hole portion are used. The cam is moved only in the sliding direction of the pole with respect to the shaft. Therefore, poor joints due to dimensional errors of the pawl and the cam can be avoided, and a margin for joining the cam and the pawl can be ensured. [0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a first view of a seat reclining device according to the present invention.
It is a top view showing an example. FIG. 2 is a sectional view taken along line CC of FIG. FIG. 3 is a plan view showing a main part of the seat reclining device according to the present invention. DESCRIPTION OF SYMBOLS 1 Lower arm 2 Upper arm 3 Rotating shaft (shaft) 4 Lock release mechanism 5 Lock mechanism 7 Two-sided wide shaft part 8 Two-sided wide hole part 41 Cam 51 Pole 52 Ratchet 71 First flat part 72 Second circular arc part 81 First 1 plane section 82 2nd plane section B clearance

Claims (1)

(57) Claims: 1. A lower arm fixed to a seat cushion, an upper arm fixed to a seat back, a shaft rotatably supporting the upper arm on the lower arm, and the lower arm and the upper arm. A lock mechanism having a slidable pawl and a ratchet provided between the pawl and a ratchet, and a lock releasing mechanism having a cam supported on the shaft and sliding the pawl, and engaging the pawl with the ratchet. The rotation of the upper arm with respect to the lower arm is regulated by maintaining the joint by the pawl and the cam, and the cam is rotated to release the joint between the cam and the pawl, and the pawl is slid by operating the pawl. When the engagement between the pawl and the ratchet is released, the upper arm is allowed to rotate with respect to the lower arm. The seat reclining device that is, the port
The cam and the cam are joined, and the pawl and the ratchet mesh.
And Nimen width shaft portion having a first arcuate portion for connecting the first planar portion and a first planar portion of the pair is parallel to the sliding direction of the pole is formed in the shaft when the engagement, the cam And a pair of second flat portions slidingly contacting the first flat portion and a second arc portion connecting the second flat portions and forming a predetermined clearance between the second flat portion and the first arc portion. A seat reclining device having a two-sided width hole.