JPS6242604B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a spring mechanism attached to a backrest portion of an automobile, which is referred to as a lumbar support by those skilled in the art.

(Prior Art) To explain the prior art to which the present invention is directed, it had the configuration shown in FIG. 1A, B, and C. In Fig. 1, A is a planar cam whose surface perpendicular to the rotational axis is F, B is a rotation knob for rotating planar cam A, and C is formed on the side wall of planar cam A. An engagement step, D is a rotation prevention engagement member that engages with the engagement step C to fix the planar cam A, and E is a spring body of a lumbar support built into the backrest of the seat. It is in elastic contact with surface F.

In the prior art, when the rotary knob B is rotated, the planar cam A rotates, and the position of the contact portion of the spring body E that is in contact with the cam surface F is changed against the elasticity of the spring body E, In other words, the spring body E is configured to be movable from the position indicated by the solid line to the position indicated by the phantom line.

(Problem to be Solved by the Invention) With the above configuration, the spring body E always tries to return to its original state and acts to push against the cam surface F, so the planar cam A that receives this acts on the spring body E There was a defect that rotated naturally due to elasticity.

Therefore, in the known example shown in FIG. 1, an engagement step C is formed on the side wall of the planar cam A, and the rotation prevention engaging body D is engaged with the engagement step C to prevent the planar cam A from moving. This prevents it from rotating back.

That is, the spring body E and the planar cam A of the prior art abut each other at point G, and since the elasticity of the spring body E acts in the direction of arrow C, the direction of arrow A, which is the direction with a lower inclination, (The slope is higher in the direction of arrow B, so you cannot slide in that direction.)

Therefore, the planar cam A is rotated in the direction of arrow D.

However, by making a slight improvement to the cam surface F, not only can the engaging stepped portion C and the anti-rotation engaging body D become unnecessary lumbar supports, but also the reversal can be reliably prevented. I can do things.

(Means for Solving the Problem) Therefore, the present invention uses a planar cam 1 with a circular front surface as a cam for advancing and retracting a spring body 4 of a lumbar support attached to the backrest of a seat of an automobile, and the cam of the planar cam 1. The surface 12 is divided into left and right halves along a bisector line X-X to form a semicircular left cam surface 13 and a right cam surface 14, and the left cam surface 13 is provided with engaging step portions a having successively different heights. , b, c are formed along the circumference, and the right cam surface 14 is provided with engaging step portions a', having successively different heights.
b' and c' are formed along the circumference, and the engagement step part a and the engagement step part a', the engagement step part b and the engagement step part b', and the engagement step part c and the engagement step part a' are formed. The connecting line with the connecting step c' is on one side of the planar camshaft, and the end of the rotation fixture 10 attached to the end of the spring body 4 snaps onto the cam surface along the connecting line. This is the ultimate lumbar support.

(Example) Fig. 3 shows the planar shape of the planar cam 1 used in the present invention. The insertion opening 3 is formed in a shape similar to a rectangular shape.

When the cam surface 12 is divided into left and right halves along the bisector line XX, the left cam surface 13, which is the left half of the cam surface 12, has an engaging stepped portion a whose height gradually increases.
b and c, and the right cam surface 14 of the right half is
An engaging stepped portion having the same height as the engaging stepped portions a, b, and c.
Form a′, b′, and c′ in a symmetrical state.

For example, when the shape of the planar cam 1 seen from the direction of the arrow P in FIG. 3 is shown in FIG. 4, the engaging step portions a,
a' are formed by overlapping at the same height. When viewed from a different direction, the engaging step portion b and the engaging step portion b', and the engaging step portion c and the engaging step portion c' are formed to overlap at the same height.

Therefore, if the rotation fixing device 10 of the spring 4 of the lumbar support is brought into contact with the engagement steps b, b', for example, as shown in FIG. 5, the engagement steps b,
Since b' are formed at the same height, no matter how strongly the rotary fixture 10 presses the engagement steps b and b', the slippage shown in FIG. 2 will not occur.

In other words, if the rotation fixture 10 engaged with the engagement step b portion attempts to shift from the engagement step b in the direction of the engagement step c, the rotation fixtures 10 will engage together. Since the engaging stepped portion b' on the opposite side acts to hold the engaging step portion b' in the direction in which it does not dislodge, the mutual movements are canceled and rotation of the planar cam 1 is reliably prevented.

Figure 6 and subsequent figures show specific embodiments of the present invention, where 5 is a fixing bracket attached to the side of the backrest, and 6 is a rotating shaft that is stretched between the brackets 5. The middle portion of the rotating shaft 6 is bent like a crank arm, and one end projects directly or indirectly outward from the bracket 5, and a rotating knob 7 is fixed thereto. The planar cam 1 is fitted and fixed symmetrically to both end portions of the rotating shaft 6, and the cam surface 1 of the planar cam 1
2 (the surface provided with the engaging steps a, b, c, a', b', c') is attached so as to face the inside of the backrest.
Projections 8, 8 projecting inward are fixed to the brackets 5, 5, and shafts 9, 8 are attached to the projections 8, 8.
The rotation fixtures 10, 10 of the spring 4 are rotatably fixed by 9. An example of the rotating fixtures 10, 10 is
It has the shape shown in FIGS. 8 and 9, and one end thereof is formed into an engaging part 11, 11 for fixing each end of the known spring 4, and the other end is the engaging step part aa' (or
bb', cc') is configured to elastically abut both at the same time.

(effect) Next, we will discuss the effect.

Since the present invention has the above-described configuration, when the rotary knob 7 is rotated, the planar cam 1 rotates, and the left cam surface 13 and right cam surface 14 of the cam surface 12 of the planar cam 1 simultaneously rotate, and the Rotating the rotating fixture 10 that is in contact with each of the engaging step portions of the cam surface 13 and the right cam surface 14 is rotated about the shaft 9;
Move spring 4 forward and backward.

In this case, when the cam surface 12 is divided into two left and right along the bisector line X-X, the left cam surface 13 of the left half of the cam surface 12 has an engaging step portion a whose height gradually increases.
b and c, and on the right half of the right cam surface 14, engaging step portions a', b', and c' having the same height as the engaging step portions a, b, and c, respectively, are formed symmetrically, The rotation fixture 10 of the spring 4 of the lumbar support is attached to the left cam surface 13.
Since the rotating fixture 10 is in contact with the engaging steps a, b, c of the right cam surface 14 and the engaging steps a', b', c' of the right cam surface 14, the rotation fixture 10 is strongly attached to the cam surface 12. Even if the cam surface 12 comes into contact with the cam surface 12, the cam surface 12 will not reverse.

(Effects) Conventionally, the configurations shown in FIG. C is an engagement step formed on the side wall surface of the planar cam A; D is an engagement member for preventing rotation that engages with the engagement step C to fix the planar cam A;
Reference numeral E denotes a spring body of a lumbar support built into the backrest of the seat, which elastically abuts against the cam surface F. In the prior art, when the rotary knob B is rotated, the planar cam A rotates, and the position of the contact portion of the spring body E that is in contact with the cam surface F is changed against the elasticity of the spring body E. In other words, the spring body E is configured to be movable from the position indicated by the solid line to the position indicated by the phantom line. With the above configuration, the spring body E always tries to return to its original state and acts to push against the cam surface F, so that the planar cam A that receives this is prevented from rotating naturally due to the elasticity of the spring body E. It was hot. Therefore, in the known example shown in FIG. 1, an engagement step C is formed on the side wall of the planar cam A, and the rotation prevention engagement body D is engaged with the engagement step C to prevent the planar cam A from moving. This prevents it from rotating back.

However, in the present invention, the cam for advancing and retracting the spring body 4 of a lumbar support attached to the backrest of a seat of an automobile is a planar cam 1 with a circular front surface, and the cam surface 12 of the planar cam 1 is bisected by the line X- The left cam surface 13 and the right cam surface 14 are formed by dividing the left cam surface 13 and the right cam surface 14 into left and right halves at The right cam surface 14 has engaging step portions having successively different heights.
a', b', and c' are formed along the circumference, the engagement step a and the engagement step a', the engagement step b and the engagement step b',
The connection line between the engagement step c and the engagement step c' is on one side of the planar camshaft, and the end of the rotation fixture 10 attached to the end of the spring body 4 is connected to the connection line. Since the lumbar support is made of a lumbar support that snaps onto the cam surface along a, b,
c and any one of the engagement steps a', b', c' of the right cam surface 14. There is no need for a device to prevent reverse rotation.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the prior art, A is a plan view, B is a front view, C is a right side view of A, Fig. 2 is an operational state diagram of Fig. 1, and Fig. 3 is a planar cam of the present invention. Side view,
Fig. 4 is a plan view of the P arrow, Fig. 5 is a perspective view of the main part, Fig. 6 is a plan view of the main part with the central part omitted, Fig. 7 is a front view of the same, Fig. 8 is a front view of the fixture, and Fig. 8 is a front view of the fixture. FIG. 9 is a plan view of the same. Explanation of symbols, 1...Flat cam, 2...Notch,
3...Insertion port, 4...Spring, 5...Bracket,
6... Rotating shaft, 7... Rotating knob, 8... Protrusion, 9... Shaft, 10... Rotating fixture, 11... Engaging portion, 12... Cam surface, 13... Left cam surface, 1
4...Right side cam surface.

Claims (1)

[Claims] 1. The cam for advancing and retracting the spring body 4 of a lumbar support attached to the backrest of a seat of an automobile, etc. is a flat cam 1 with a circular front surface, and the cam surface 12 of the flat cam 1 is 2.
The left cam surface 13 and the right cam surface 14 are formed by dividing the left cam surface 13 and the right cam surface 14 into semicircular arcs by dividing the left cam surface 13 and the right cam surface 14 into two along the equal dividing line X-X, and the left cam surface 13 has engaging stepped portions a, b, which have successively different heights.
c is formed along the circumference, and engagement steps a', b', and c' of different heights are formed sequentially along the circumference on the right cam surface 14, and the engagement steps a and c are formed along the circumference. The coupling line between the engagement step a', the engagement step b and the engagement step b', and the engagement step c and the engagement step c' are on one side of the planar camshaft, and the The end of the rotation fixture 10 attached to the end of the spring body 4 is a lumbar support that snaps onto the cam surface along the connection line.