Folding outer mirror

The object of this invention is to provide a folding outer mirror, in which the cost reduction, the prevention of large sizes and heavy weights, and higher stiffness of the stopper mechanism can be obtained. The folding outer mirror includes a mirror base extending outside from a side surface of vehicle body, a mirror assembly attached rotatably to the mirror base, and a stopper mechanism for stopping the mirror assembly at a predetermined position. The stopper mechanism is provided with a base-side engaging surface formed in the mirror base, and a body-side engaging surface formed in the mirror assembly and being in plane contact with the base-side engaging surface at a predetermined position. The base-side engaging surface and the body-side engaging surface are formed such that a raising angle relative to a rotating direction of the mirror assembly becomes a sharp angle.

FIELD OF THE INVENTION

The present invention relates to a folding outer mirror providing with a rotatable mirror assembly mounted in the side of vehicle body.

BACKGROUND OF THE INVENTION

As an outer mirror attached to the side of vehicle body, it is, in general, adapted to use a folding outer mirror, which is rotated between a normal position to direct a mirror surface of a mirror approximately at a right angle relative to the side of vehicle body and a folded position to be folded in the side of vehicle body. In the folded position, the mirror surface is, in general, arranged to direct a rear position opposing to the side of vehicle body by rotating the mirror assembly in a direction of vehicle body. The folding outer mirror is constituted to rotate to a forward retracted position prepared for outside forces such as an unexpected crash or contact from the rear side of car such that the mirror assembly can be retracted by rotating in the forward.

The folding outer mirror is provided with a mirror base extending outside from the side surface of vehicle body and a mirror assembly being rotatably mounted in the mirror base. The folding outer mirror is provided with a positioning mechanism to stop the mirror assembly at a normal position and a stopper mechanism to stop the mirror assembly at a folded position or a retracted position when the mirror assembly rotates from the normal position to a rear folded position or a forward retracted position.

The stopper mechanism is constituted to compose, for example, of an arcuate groove formed in the mirror base and a convex part provided in the mirror assembly and to move the convex part along the arcuate groove. For example, it may be referred to Japanese Patent unexamined laid-open publication No. 9806 of 2004 or No. 282088 of 2006. In such a stopper mechanism, when the mirror assembly is folded in a folded position, one side end surface of the convex part (an engaging surface) is in contact with a circumferential end surface (an engaging surface) of the arcuate groove, thus to regulate a movement of the mirror assembly. When the mirror assembly is rotated to a retracted position, the other side end surface of the convex part (an engaging surface) is in contact with the other end (an engaging portion), thus to regulate a movement of the mirror assembly. As above mentioned, when the folding outer mirror is rotated rearwards or forwards from a normal position, the folding outer mirror is designed to stop at a folded position or a retracted position by contacting each side end surface of the convex part with one end or the other end of the arcuate groove. The engaging surface as contacted and engaged with each other is formed on a plane crossing at a right angle relative to a rotating direction of the mirror assembly.

SUMMARY OF THE INVENTION

When the mirror assembly rotates to a retracted position, large force caused by unexpected crash or contact may be urged to an arcuate groove formed in the mirror base and a convex part provided in the mirror assembly. Thus, the arcuate groove and the convex part are required to have a high stiffness. In conventional folding outer mirrors, the arcuate groove and the convex part are composed of high-intensity materials such as metal or plastics containing glass fiber in order to have the predetermined stiffness as required. As a result, conventional folding outer mirrors may result in an increase in cost. Then, it is considered to require a large contact area between the large convex part and the arcuate groove so as to have the stiffness as required without high-intensity materials. In this case, it results in large sizes and heavy weights of the folding outer mirror, as the stopper mechanism becomes too large.

Accordingly, an object of the present invention is to provide a folding outer mirror having the desired cost reduction, the prevention of large sizes and heavy weights, and the high stiffness of the stopper mechanism.

The invention according to Claim1invented so as to solve the above problem is a folding outer mirror, which includes a mirror base extending outside from the side surface of vehicle body, a mirror assembly attached rotatably to the mirror base, and a stopper mechanism for stopping the mirror assembly at a predetermined position. Then, it is characterized in that the stopper mechanism comprises a base-side engaging surface formed in the mirror base, and a body-side engaging surface formed in the mirror assembly and being in plane contact with the base-side engaging surface at a predetermined position. Furthermore, the base-side engaging surface and the body-side engaging surface are constituted such that a raising angle relative to a rotating direction of the mirror assembly is a sharp angle.

“A rotating direction of the mirror assembly” in the invention means a tangential direction at any point in a rotating circumferential direction. “A raising angle” means an angle raising the engaging surface directing from one side to the other side of the mirror base and the mirror assembly, and an angle formed in the solid side of the engaging surface relative to the rotating direction.

According to the above constitution, the force acting directly on plane, which is perpendicular to the engaging surface, becomes smaller than the outside force urged in the rotating direction, and the contact area between the engaging surfaces is larger compared with the case where the engaging surface poses at a right angle relative to the rotating direction. That is, as the contact pressure in the contact surface is small, the same or similar effect to increase the stiffness of the mirror base and the mirror assembly can be obtained. Furthermore, as an angle of the member forming the engaging surface relative to the rotating direction becomes an obtuse angle by making the raising angle from the rotating direction of the engaging surface to be a sharp angle, the stress concentration factor is greatly improved and the stress concentration can be prevented. Therefore, the stopper mechanism having a high degree of stiffness can be obtained without using high-intensity material and the cost reduction thereof can be also obtained. Furthermore, as the engaging surface itself is not required to be large, large sizes and heavy weights of the stopper mechanism can be prevented.

The invention relating to Claim2is characterized by the following elements on the basis of the folding outer mirror as described in Claim1. That is, the predetermined position is two positions, that is, at the folded position and at the retracted position of the mirror assembly, and the base-side engaging surface and the body-side engaging surface are respectively formed to have two surfaces.

in such a constitution, in the folded position and the retracted position receiving a comparatively large stress caused by outside forces such as an unexpected crash or contact, the higher stiffness of the mirror base and the mirror assembly can be obtained. Accordingly, it is effective and advantageous therein.

The invention relating to Claim3is characterized by the following elements on the basis of the folding outer mirror as described in Claim1or2. That is, the mirror base is provided with the base-side arcuate groove having the same center as a rotation center of the mirror assembly, and the mirror assembly is provided with the body-side convex part inserting in the base-side arcuate groove. Further, the base-side engaging surface is constituted to have a circumferential end surface of the base-side arcuate groove, and the body-side engaging surface is constituted to have an end surface in a rotating direction of the body-side convex part.

In such a constitution, as a thick-wall part can be obtained in the back of the base-side engaging surface by providing the base-side arcuate groove in the mirror base, the stiffness thereof can be further improved to be higher.

The invention relating to Claim4is characterized by the following element on the basis of the folding outer mirror as described in Claim3. That is, the body-side convex part is integrally formed to have a stiffening rib extending in a circumferential direction.

In such a constitution, as the body-side convex part itself becomes higher in stiffness as a single unit of the body-side convex part itself, still higher stiffness of the stopper mechanism can be obtained.

The invention relating to Claim5is characterized by the following elements on the basis of the folding outer mirror as described in Claim1or2. That is, the mirror base is provided with the base-side convex part, the mirror assembly is provided with the body-side convex part engaged with the base-side convex part. Furthermore, the base-side engaging surface is constituted at an end surface in a rotating direction of the mirror assembly of the base-side convex part, and the body-side engaging surface is constituted at an end surface in a rotating direction of the body-side convex part.

In such a constitution, a higher stiffness of the stopper mechanism can be obtained by a comparatively simple constitution.

The invention relating to Claim6is characterized by the following elements on the basis of the folding outer mirror as described in Claim1. That is, in the folding outer mirror comprising the mirror base extending outside from the side surface of vehicle body and the mirror assembly attached rotatably to the mirror base, the mirror base is provided with the base-side arcuate groove having the same center as a rotation center thereof, the mirror assembly is provided with the body-side convex part inserted in the base-side arcuate groove, the mirror assembly is provided with the body-side arcuate groove having the same center as a rotation center thereof, and the mirror base is provided with the base-side convex part inserted in the body-side arcuate groove. Furthermore, the base-side engaging surface is constituted at a circumferential end surface of the base-side arcuate groove and an end surface in a rotating direction of the mirror assembly of the base-side convex part, the body-side engaging surface is constituted at an end surface in a rotating direction of the body-side convex part and a circumferential end surface of the body-side arcuate groove. Then, when the mirror assembly is positioned at a rearward folded position or a forward retracted position, the body-side convex part is in contact with the circumferential end surface of the base-side arcuate groove, and the base-side convex part is in contact with the circumferential end surface of the body-side arcuate groove.

In such a constitution, as the body-side convex part is in contact with a circumferential end of the base-side arcuate groove and the base-side convex part is in contact with a circumferential end of the body-side arcuate groove, the contact area between the convex part and the arcuate groove can be made to be larger. Accordingly, as the outside force urged to the mirror assembly is dispersed at the convex part and the arcuate groove, the higher stiffness of the stopper mechanism composing of the convex part and the arcuate groove can be obtained without using high-intensity materials, and the cost reduction thereof can be obtained. As the convex part is not required to be large as its single unit, large sizes of the stopper mechanism composing of the convex part and the arcuate groove can be prevented, and heavy weights thereof can be also prevented.

The invention relating to Claim7is characterized by the following elements on the basis of the folding outer mirror as described in Claim6. That is, at least one of a combination of the body-side convex part and the base-side arcuate groove and a combination of the base-side convex part and the body-side arcuate groove are provided as a plurality of combinations.

In such a constitution, as the contact area between the convex part and the arcuate groove can be made to be larger, still further higher stiffness of the stopper mechanism can be obtained.

The invention relating to Claim8is characterized by the following element on the basis of the folding outer mirror as described in Claim7. That is, at least one of the body-side convex part and the base-side convex part is integrally provided with the stiffening rib extending in a circumferential direction.

In such a constitution, as the stiffness of the convex part itself as a single unit is made to be higher, the further higher stiffness of the stopper mechanism can be obtained.

According to the present invention, it is effective and advantageous to provide a folding outer mirror in which the cost reduction, the prevention of large sizes and heavy weights, and the higher stiffness of the stopper mechanism can be obtained.

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of a folding outer mirror relating to the present invention will be described in detail with respect to the attached drawings. In this embodiment, it will be given an example of an electric folding outer mirror, which is adapted to rotate the mirror assembly with electricity.

As shown inFIG. 1, the folding outer mirror1relating to this embodiment is provided with a mirror base10extending from the side surface of vehicle body (as not shown) toward the side and a mirror assembly30as been rotatably attached to the mirror base10. The mirror assembly30is constituted such that a mirror as not shown, a holder (as not shown) holding the mirror, a frame (as not shown) holding the holder slantably, and an electric folding outer mirror (as not shown) rotating the mirror assembly30are housed in the mirror housing31.

The electric folding outer mirror is provided with a shaft (as not shown) extending in an appropriately up-and-down direction and a motor (as not shown) rotating the mirror assembly30around the shaft. The shaft is attached to a mounting scat of the mirror base10at its lower extremity. The mirror assembly30is adapted to rotate between a normal position P1(as shown inFIG. 2) as developed outside and a folded position P2(as shown inFIG. 3A) as folded inside by rotating around the shaft through various gears (as not shown). The folding outer mirror1is constituted to have a forward retracted position P3(as shown inFIG. 3B) so as to retract the mirror assembly30by forward rotations in preparation for outside forces such as unexpected crash or contact from the rear side of a vehicle body.

The mirror base10is provided with a mounting plate12fixed in a mounting seat (as not shown) formed in a pillar portion or the like positioned in a side door of vehicle body and a base body13extending from the lower part of the mounting plate12toward a side direction. The mounting plate12and the base body13are integrally constituted by synthetic plastic or the like. The mounting seat11of the shaft of an electric folding unit is formed on the base body13. The mounting seat11is formed to have a plurality of bolt holes11a. Then, a bolt (as not shown) is screwed on a boss of shaft through the bolt hole11afrom the lower part of the base body13, then to fix the shaft therein.

A crutch mechanism (as not shown) is provided between the shaft and the frame. The crutch mechanism is designed to position the mirror assembly30between the normal position P1(as referred toFIG. 2) and the folded position P2(as referred toFIG. 3A) by regulating the rotation thereof. Also, the crutch mechanism is designed to accept the rotation to the retracted position P3(as referred toFIG. 3B) of the mirror assembly30at the time when outside forces such as unexpected crash or contact is urged from the rear side of vehicle body.

The folding outer mirror1is provided with a stopper mechanism2for stopping the mirror assembly30at the folded position P2or the retracted position P3when the mirror assembly30rotates from the normal position P1to the rearward folded position P2or the retracted position P3.

The stopper mechanism2is provided with base-side engaging surfaces51a,51bformed in the mirror base10and body-side engaging surfaces53a,53bbeing in a plane contact with the base-side engaging surfaces51a,51bat the predetermined position (the folded position P2or the retracted position P3) formed in the mirror assembly30. In the folded position P2, the base-side engaging surface51aand the body-side engaging surface53bare in plane contact with each other in a plane. In the retracted position P3, the base-side engaging surface51band the body-side engaging surface53bare in contact with each other. The base-side engaging surfaces51a,51band the body-side engaging surfaces53a,53bare constituted such that the raising angles thereof become an acute angle (as referred toFIG. 4) relative to a rotating direction D of the mirror assembly30. The rotating direction D means a tangential direction at any point of rotational circumferential direction in the above. The raising angle θ is an angle raising an engaging surface from the side of the mirror base10or the mirror assembly30toward the other side on the basis of rotating direction, and means an angle in the solid side of the engaging surface relative to the rotating direction D.

In this embodiment, the stopper mechanism2is constituted that the base-side arcuate groove14is coaxially formed to have the same center as a rotation center of the mirror assembly30in the mirror base10and the body-side convex part33inserted into the mirror assembly30is provided in the base-side arcuate groove14. The body-side arcuate groove35is formed in the mirror assembly30in the same rotation center as the mirror assembly30. The base-side convex part16inserted into the body-side arcuate groove35is provided in the mirror base10. When the mirror assembly30is at the rearward folded position P2or the forward retracted position P3, the body-side convex part33is adapted to be in contact with the circumferential end14R (at a position of the folded position P2) or14L (at a position of the retracted position P3) of the base-side arcuate groove14. The base-side convex part16is in contact with the circumferential end35aL (35bL) (at a folded position P2) or35aR (35bR) (at a retracted position P3) of the body-side arcuate groove35. As later described, the right end surface33R and the left end surface33L, as being surfaces of the both ends of the body-side convex part33, is slantingly formed such that the raising angle θ becomes an acute angle. The circumferential end14R or14L of the base-side arcuate groove14, as being in contact with the circumferential end surface33R,33L of the body-side convex part33, is slantingly formed such that the raising angle θ becomes an arcuate angle. The left end surface33L of the body-side convex part33is constituted to be the body-side engaging surface53band the circumferential end14L of the base-side arcuate groove14is constituted to be the base-side engaging surface51b. The right end surface33R of the body-side convex part33is constituted to be the body-side engaging surface53aand the circumferential end14R of the base-side arcuate groove14is constituted to be the base-side engaging surface51a.

Hereinafter, a constitution of the stopper mechanism2will be described in detail. As shown inFIGS. 1 and 2, the base-side arcuate groove14is formed in the surrounding of the mounting seat11arranged on the upper surface of the base body13of the mirror base10. The base-side arcuate groove14is coaxially formed in a center of the shaft, that is, a rotation center of the mirror assembly30. The base-side arcuate groove14is farmed at two positions on the concentric circle. Each of the base-side arcuate grooves14,14is arranged to grasp an intermediate portion15to form the predetermined narrow central angle therebetween. Both are mutually formed not to interfere with each other. As shown inFIG. 2, the base-side arcuate groove14is constituted to have a central angle composed of a rotation angle A (the rearward folding angle) ranging from a normal position P1to a folded position P2(as referred toFIG. 3A), a rotation angle B (the forward folding angle) ranging from a normal position P1to a retracted position P3(as referred toFIG. 3B), and a rotation angle C equivalent to a circumferential length of the body-side convex part33(a length in the rotating direction of the mirror assembly30) as described later. In this embodiment, the central angle of the base-side arcuate groove14is a little smaller than 120 degrees.

As shown inFIG. 1, a through hole34for inserting the shaft is formed on the lower surface32opposite to the mounting seat11of the mirror housing31of the mirror assembly30. The through hole34has the same circular form as the mounting seat11. The body-side convex part33as inserted into the base-side arcuate groove14is provided in the surrounding of the through hole34. The body-side convex part33is constituted to extend from the lower surface32of the mirror housing31to the lower side. Two body-side convex parts33is coaxially provided and each of the body-side convex part33,33is inserted into each of two base-side arcuate groove14,14. The body-side convex part33is constituted by the same material such as synthetic plastics to be integrally formed with the mirror housing31.

As shown inFIG. 2A, when the mirror assembly30is positioned at a normal position P1, the right end surface33R (as referred toFIG. 2B) (hereinafter, a left-and-right direction in this specification is a standard direction as seen from the rotation center at a condition assembling the mirror assembly30and the mirror base10) as seen from the rotation center of the body-side convex part33is adapted to be a position spaced by a rotation angle A between the normal position P1and the folded position P2from the right end surface14R of the base-side arcuate groove14. At this time, the left end surface33L (as referred toFIG. 2B) of the base-side arcuate groove33is positioned at a separated position by a rotation angle B ranging between the normal position P1and the retracted position P3from the left end surface14L of the base-side arcuate groove14.

As shown inFIG. 1,FIG. 2B, andFIG. 4, the body-side convex part33is slantingly formed as the body-side convex part33such that the right end surface33R and the left end surface83L, as being circumferential both ends, mutually approaches at the side of their lower extremity. The right end surface33R as being circumferential end surface of the body-side convex part33is constituted to be the body-side engaging surface53band the left end surface33L is constituted to be the body-side engaging surface53a. The slanting angles (the raising angle θ relative to the rotating direction D) of the end surfaces33R,33L are respectively equal and the right end surface33R and the left end surface33L are mutually constituted in a shape of plane symmetry such that a line connecting between lower ends (lower extremities) of end surfaces33R,33L constitutes a short side of isosceles trapezoid in section (as referred toFIG. 4). Although the body-side convex part33is formed like a solid form, it is not limited thereto. It may be formed like being a hollow form by emptying the internal portion thereof. In this way, light weight and cost reduction of the mirror assembly30can be obtained. InFIGS. 2 and 3, the section of the body-side convex part33as shown by hatchings shows a base and a horizontal section in a long side of trapezoid.

The right end surface14R of the base-side arcuate groove14(as referred toFIG. 2) slants at the same slanting angle (the raising angle θ relative to the rotating direction) as the right end surface33R of the body-side convex part33. As shown inFIG. 3A, when the mirror assembly30is at a folded position P2, the right end surface14R of the base-side arcuate groove14and the right end surface33R of the body-side convex part33are mutually contacted in plane. The left end surface14L (as referred toFIG. 2B) of the base-side arcuate groove14slants at the same slanting angle as the left end surface331, of the body-side convex part33. As shown inFIG. 3B, when the mirror assembly30is at the retracted position P3, the left end surface14L of the base-side arcuate groove14and the left end surface33L of the body-side convex part83are in contact with each other.

The body-side convex part33and the base-side arcuate groove14are constituted as a combination (a combination of stoppers). The combination of stoppers is formed as two combinations.

As shown inFIG. 1andFIG. 2A,2B, a pair of base-side convex parts16,16extending in the side of the mirror assembly30is formed on an upper surface of the base body13positioned at both ends in a circumferential direction of the base-side arcuate groove14. The base-side convex part16is inserted into the body-side arcuate groove35as later described. The base-side convex part16is constituted by the same material such as synthetic plastics to be integrally formed with the mirror base10. The base-side convex part16(hereinafter, it may be referred to as “base-side convex part16a”) formed in the intermediate part15positioned between the neighboring base-side arcuate grooves14,14is used as both the left end of one base-side arcuate groove14and the right end of the other base-side arcuate groove14. The base-side convex parts16are formed at three positions, that is, the right end of one base-side arcuate groove14, the left end thereof (also use of the right end of the other base-side arcuate groove14), and the left end of the other base-side arcuate groove14. These three base-side convex parts16,16a,16are formed in an equal pitch at the central angle of 120 degrees from the rotation center. The base-side convex part16afor both uses thereof is constituted that the both circumferential ends are opposed to a pair of base-side arcuate grooves14,14, and the other base-side convex parts16,16are constituted that the only one circumferential end is opposed to the base-side arcuate groove14,14.

In the base-side convex part16aformed in an intermediate part positioning between the neighboring base-side arcuate grooves14,14, both of the circumferential end surfaces16R,16L slant at the same slanting angle as the left end surface14L and the right end surface14R of the base-side convex part16arespectively. As a result, the circumferential end surface16L of the base-side convex part16aand the right end surface14R of the base-side arcuate groove14lie on a same plane, and the circumferential end surface16R of the base-side convex part16aand the right end surface14R of the base-side arcuate groove14lie on a same plane. In the base-side convex part16(as shown in a middle and a left side ofFIG. 2B) positioned at one end of the base-side arcuate groove14and at the opposite end of the intermediate part15, the circumferential end surface16R positioned in the side of the base-side arcuate groove14slants at the same slanting angle as the left end surface14L of the base-side arcuate groove14. As a result, the circumferential end surface16R of the base-side arcuate groove14and the left end surface14L of the base-side arcuate groove14lie on a same plane. The circumferential end surface in the reverse side of the circumferential end surface16R is formed to be orthogonal to an upper surface of the base body18and to extend a vertical direction. In the base-side convex part16(as shown in a middle and a right side ofFIG. 2B) positioned at the other base-side arcuate groove14and at the opposite end of the intermediate part15, the circumferential end surface16L positioned in the side of the base-side arcuate groove14slants at the same angle as the left end surface14R of the base-side arcuate groove14. As a result, the circumferential end surface16L of the base-side arcuate groove14and the right end surface14R of the base-side arcuate groove14lie on a same plane. The circumferential end surface in the reverse side of the circumferential end surface16L is formed to be orthogonal to an upper surface of the base body13and to extend a vertical direction.

The body-side arcuate groove35for inserting the base-side convex part16is formed in the surrounding of the through hole34of the mirror housing31of the mirror assembly30. The body-side arcuate groove35is formed to range like an arcuate curve between two body-side convex parts33,33at a narrow side and a wide side of central angle thereof. That is, the body-side arcuate groove35is constituted by the body-side arcuate groove35a,35b, which are respectively long and short in the arcuate curves. Then, the body-side arcuate grooves35a,35band the body-side convex parts33,33are constituted to form a circle, of which center is a center of rotation of the mirror assembly30. The base-side convex part16ahaving both use (the base-side convex part16aof which the circumferential both ends are opposite to the base-side arcuate grooves14,14) formed in the intermediate part15is inserted in the body-side arcuate groove35bas being short in the arcuate curve, and the two base-side convex parts16, of which only one of the circumferential ends is opposed to the base-side arcuate groove14, are inserted in the body-side arcuate groove35aas being long in the arcuate curve. A pair of the base-side convex parts16,16positioned at both ends of the base-side arcuate groove14are inserted in the body-side arcuate groove35aas being long in the arcuate curve and the body-side arcuate groove35brespectively. A pair of the base-side convex parts16,16and a pair of the body-side arcuate grooves35a,35bare adapted to constitute one combination (a stopper set). In this embodiment, two sets of stopper sets are constituted.

As shown inFIG. 2B, the circumferential end surfaces35aL,35bL of the body-side arcuate grooves35a,35bslant at the same slanting angle as the right end surface33R of each body-side convex part33respectively. As a result, the circumferential end surfaces35aL,35bL of each body-side arcuate grooves85a,35band the right end surfaces33R,38R of each body-side convex part33lie on a same plane. The circumferential end surfaces35aR,35bR of each body-side arcuate grooves35a,85bslant at the same slanting angle as the left end surface33L of each body-side convex part33. As a result, the circumferential end surfaces35aR,35bR of each body-side arcuate grooves35a,35band the left end surface33L,33L of each body-side convex part33lie on a same plane.

As shown inFIG. 2A, when the mirror assembly30is positioned at a normal position P1, the left end surface35aL of the body-side arcuate groove35aas being long in the arcuate curve (as referred toFIG. 2B) is positioned at a position spaced by the rotation angle A ranging between the normal position P1and the folded position P2from the left end surface16L of one base-side convex part16(as referred toFIG. 2B), which only one end of the circumferential ends is opposed to the base-side arcuate groove14. At this time, the right end surface35aR of the body-side arcuate groove35a(as referred toFIG. 2B) as being long in the arcuate curve is positioned at a position spaced by the rotation angle B ranging between the normal position P1and the retracted position P3from the right end surface16R of the other base-side convex part16(as referred toFIG. 2B), which only one end of the circumferential ends is opposed to the base-side arcuate groove14.

When the mirror assembly30is positioned at the normal position P1, the left end surface35bL of the body-side arcuate groove35bas being short in the arcuate curve is positioned at a position spaced by the rotation angle A ranging between the normal position P1and the folded position P2from the left end surface16L of one base-side convex part16(as referred toFIG. 2B) having two functions, which only one end of the circumferential ends is opposed to the base-side arcuate groove14. At this time, the right end surface35bR of the body-side arcuate groove35bas being short in the arcuate curve is positioned at a position spacing away the rotation angle B ranging between the normal position21and the retracted position23from the right end surface16R of the base-side convex part16having two functions.

According to the embodiment as above mentioned, both a combination of the body-side convex part33and the base-side arcuate groove14, and a combination of the base-side convex part16and the body-side arcuate groove35are respectively provided to have two sets to form a stopper mechanism2.

Next, movements of each part of the folding outer mirror1as constituted like the above will be described. As shown inFIG. 3A, when the mirror assembly30rotates to the folded position P2, the right end surface33R of the body-side convex part33(body-side engaging surface53a) contacts the right end surface14R of the base-side arcuate groove14(base-side engaging surface51a) and the left end surface35bL of the body-side arcuate groove35bas being long in the arcuate curve contacts the left end surface16L of one base-side convex part16, which only one end of the circumferential ends is opposed to the base-side arcuate groove14. In this embodiment, both a combination of the body-side convex part33and the base-side arcuate groove14, and a combination of the base-side convex part16and the body-side arcuate groove35are respectively provided to have two sets. Thus, the right end surface33R of the another pair of body-side convex part33(body-side engaging surface53a) contacts the right end surface14R of the base-side arcuate groove14((base-side engaging surface51a), and the left end surface35aL of the body-side arcuate groove35aas being short in the arcuate curve contacts the left end surface16L of the base-side convex part16having both functions.

Next, movements of each part of the folding outer mirror1as constituted like the above will be described. As shown inFIG. 3B, when the mirror assembly30rotates to the retracted position P3, the left end surface33L of the body-side convex part33(body-side engaging surface53b) contacts the left end surface14L of the base-side arcuate groove14(base-side engaging surface51b) and the right end surface35bR of the body-side arcuate groove35bas being long in the arcuate curve contacts the left end surface16L of one base-side convex part16, which only one end of the circumferential ends is opposed to the base-side arcuate groove14. In this embodiment, both a combination of the body-side convex part33and the base-side arcuate groove14, and a combination of the base-side convex part16and the body-side arcuate groove35are respectively provided to have two sets. Thus, the left end surface33L of the another pair of body-side convex part33(body-side engaging surface53b) contacts the left end surface14L of the base-side arcuate groove14((base-side engaging surface51a), and the left end surface35aR of the body-side arcuate groove35aas being short in the arcuate curve contacts the right end surface16R of the base-side convex part16having both functions.

As above mentioned, according to this embodiment, the circumferential ends33R,33L (body-side engaging surfaces53a,53b) of the body-side convex part33are constituted to slant such that the raising angle relative to the rotating direction D of the mirror assembly30becomes an acute angle, the circumferential ends14R,14L (base-side engaging surface51a,51b) of the base-side arcuate groove14are constituted to slant such that the raising angle relative to the rotating direction D of the mirror assembly30becomes an acute angle. Then, the stiffness of the stopper mechanism2can be improved to enhance. This is based on the following reason.

As shown inFIG. 4, when the right end surface33R of the body-side convex part33contacts the right end surface14R of the base-side arcuate groove14, the outside force urged to the body-side convex part33is divided into a force acting directly on plane F1=F·sin θ perpendicular to the right end surface33R of the body-side convex part33, and a separate force in the slipping direction F2=F·cos θ. The force acting directly on plane F1urged to the right end surface33R of the body-side convex part33becomes smaller than the outside force F, and the end surface of the contact area is larger than one in case of a right angle. Then, the plane pressure in the contact surface becomes small, and functions toward an advantageous direction relative to a stiffness of the body-side convex part33. As a shearing length L of the body-side convex part33becomes longer than one in case of a right angle, the shearing intensity of the body-side convex part33becomes stronger. As an angle of the base part of the body-side convex part33becomes an obtuse angle, and a stress concentration coefficient can be greatly improved and prevented a concentration of stress. The stress concentration coefficient can be improved in case of a thick base part. When the arising angle θ relative to a horizontal plane of the circumferential end33L,33R of the body-side convex part33is small, the force running on along the right end surface14R or the left end surface (as not shown) of the base-side arcuate groove14becomes large. In this case, the slanting angle θ is designed to set a larger value than the predetermined angle, at which the body-side convex part33does not run on relative to the right end surface14R or left end surface (as not shown). In such a constitution, the mirror assembly30is definitely engaged at the predetermined position (a folded position P2or retracted position P3), and never runs on the base member13.

The above embodiment will be compared with a case where the raising angles of the base-side engaging surface and the body-side engaging surface are a right angle or an obtuse angle respectively.

As shown inFIG. 5A, when the raising angle 01relative to a rotating direction D of the base-side engaging surface51cand the body-side engaging surface53cis a right angle, the body-side engaging surface53cof the body-side convex part33receives an outside force F directly. Then, the force in this case is larger than one of the above embodiment, and the contact area is smaller than one of the above embodiment. Accordingly, this contact pressure of the abutting surface is larger than one of this embodiment. As a length Ll of the shearing force of the body-side convex part33is shorter than one of this embodiment, a shearing intensity of the body-side convex part33makes stronger. As a result, this embodiment is understood to be higher in stiffness than a case where the raising angle 01of each engaging surface51c,53cis a right angle.

As shown inFIG. 5B, when the raising angle θ2relative to a rotating direction D of the base-side engaging surface51and the body-side engaging surface53dis an obtuse angle, the body-side engaging surface53dof the body-side convex part33receives an outside force F separated into a direct contact pressure F3=F·sin θ2perpendicular to the body-side engaging surface53dand a separate force F4=F·cos 02in a slipping direction. The direct contact pressure F3as received on the body-side engaging surface53dof the body-side convex part33is smaller than an outside force F, and the contact area is larger than one of the case where the end surface thereof is a right angle. Thus, the contact pressure of the contact area becomes smaller, and functions to be an advantageous side relative to a stiffness of the body-side convex part33. As a length of shearing force of the body-side convex part33becomes larger than one of the case where the end surface thereof is a right angle, the shearing intensity of the body-side convex part33becomes stronger. Then, it functions to be an advantageous side relative to a stiffness of the body-side convex part33, even in a case where the raising angle θ2is an obtuse angle. However, as an angle of the base of the body-side convex part33becomes an obtuse angle, it results in a concentration of the stress and a worse stress concentration coefficient caused by a thinner base. As above mentioned, the above embodiment is understood to be higher in stiffness than the case where the raising angle θ2of each engaging surface51c,53cis an obtuse angle.

Furthermore, compared with a case where a contact area between the convex part and the arcuate groove is one spot, the abutting part can be greatly increasing and the contact area can be larger in conventional stopper mechanism. More specifically, a combination of the base-side convex part16and the body-side arcuate groove35other than a combination of the body-side convex part33and the base-side arcuate groove14can increase a number of the abutting part without a change of whole plane section of the stopper mechanism2. Further, as the both of the above combinations are respectively provided to have two sets, the abutting part can be still increasingly doubled.

As a result, as the outside force (rotating force) received on the mirror assembly30is designed to disperse into the body-side convex part33, the base-side arcuate groove14, the base-side convex part16and the body-side arcuate groove35, the stress per unit area received on each part can be made small. Thus, high stiffness and cost reduction of the stopper mechanism2can be obtained without high-intensity material. As it is not required to be large sizes of the body-side convex part33and the base-side convex part16, a large-scale tendency of the stopper mechanism2or the folding outer mirror1can be prevented. Then, a heavy-weight tendency of the stopper mechanism2and the folding outer mirror1can be prevented.

As shown inFIG. 6, it may be constituted to form a stiffening rib37extending in circumferential both sides in the outer spherical side of the body-side convex part33. The stiffening rib37is mounted upright in a area positioned in an outer spherical side of the body-side arcuate groove35provided under a lower surface of the mirror housing31, and is constituted by triangular plates as integrally formed together with the mirror housing31and the body-side convex part33. In such a constitution, a stiffness of the body-side convex part33can be made higher. The circumferential both sides of the body-side convex part33as been a form of trapezoid may be provided with the same form of stiffening rib.

Next, the result analyzed by FEM (finite element method) will be described with respect to the base-side engaging surface51a,51band the body-side engaging surface53a,53brelating to the present invention.

As shown inFIG. 7, the FEM analysis model100is constituted by the base member110and the body member130. The base member110is provided with the base-side convex parts116,116formed in the base-side arcuate groove114and the circumferential both ends respectively. The right circumferential end114R of the base-side arcuate groove114and the left end116L of the right base-side convex part116slant at a raising angle of an obtuse angle relative to a rotating direction of the body member130to lie on the same plane, which constitutes the base-side engaging surface51a. The left circumferential end part114L of the base-side arcuate groove114and the right end surface116R of the left base-side convex part116lie on the same plane as opposed to the base-side engaging surface51a, and then to be a form of plane symmetry, which constitutes the base-side engaging surface51b. The base-side arcuate groove114and the base-side convex parts116,116are constituted to provide one more set thereof in order to form a symmetry in placing astride a rotation center of the body member130.

The body member130is provided with the body-side convex part133and the body-side arcuate groove135,135formed in left and right both sides. The right end133R of the body-side convex part133and the left circumferential end135L (in the side of the body-side convex part133) of the body-side arcuate groove135slant at the same raising angle of obtuse angle relative to a rotating direction of the body member130so as to lie on the same plane, which constitutes the body-side engaging surface53b. The left end133L of the body-side convex part133and the right circumferential end135R in the side of the body-side convex part133) of the body-side arcuate groove135lie on the same plane as placed on both sides of the body-side convex part133to form the same plane, which constitutes the body-side engaging surface53b. The body-side convex part133and the body-side arcuate groove135,135are constituted to be placed at both sides of the rotating center of the body member130to be a form of symmetry and to form one more set.

With use of the above FEM analysis model100, the FEM analysis has been performed at various conditions as to an inner side101, an outer side102, and a deep side103of the body-side convex part133.

At first, when the raising angle of engaging surface is appropriately set in a range between 50 degrees and 110 degrees, and a maximum principal stress received on an inner side101, an outer side102, and the deep side103is analyzed, the result is shown inFIG. 8. In the inner side, the maximum principal stress decreases as the raising angle decreases. In the outer side, the maximum principal stress is a peak at an angle of 90 degrees, and decreases as the raising angle decreases. In the deep side, the maximum principal stress is a peak at an angle of 90 degrees, decreases at an angle of 80 degrees, increases at an angle of 70 degrees, and decreases at an angle of 50 degrees. In addition, the maximum principal stress is a minimum value at an angle of 110 degrees.

As above mentioned, in a range being a smaller than 90 degrees in the raising angle, it has been found that the maximum principal stress urged on each part of the body-side convex part133decreases in general as the raising angle decreases.

Next, when the raising angle of engaging surface is appropriately set in a range between 50 degrees and 90 degrees, the maximum principal stress urged on the inner side101, the outer side102, and the deep side103of the body-side convex part133has been analyzed in case of being with and without the stiffening rib, the result shows inFIG. 9. As shown inFIG. 9A, although the maximum principal stress decreases a little in the inner side in case of having the stiffening rib, there are few influences by the fact of with or without the stiffening rib. In addition, the maximum principal stress decreases in a range that the raising angle is less than or equal to 65 degrees in case of no stiffening rib. As shown inFIG. 9B, the maximum principal stress is small in the outer side in case of having the stiffening rib. Then, it is greatly influenced by the fact whether the stiffening rib exists or not. In addition, the maximum principal stress decreases in a range that the raising angle is less than or equal to 60 degrees in case of no stiffening rib. As shown inFIG. 9C, the maximum principal stress decreases a little in the deep side in case of having the stiffening rib. Then, it influences a few on the fact whether the stiffening rib exists or not. In addition, the maximum principal stress decreases in a range that the raising angle is less than or equal to 60 degrees in case of no stiffening rib.

As above mentioned, it has found to obtain an advantageous effect that the maximum principal stress is small in the outer side of the body-side convex part133as the stiffening rib provided, compared with the case having no stiffening rib.

Next, the frictional force μ of the engaging surface is set to be [0.1], [0.2], and [0.3] as the folding torque F urged to the body member130and the raising angle of the engaging surface is appropriately set in a range between 60 degrees and 90 degrees. Analyzing the rising force urged to the body member130, the result shown inFIG. 10can be obtained.

The mirror assembly is ordinarily set in the mirror base to be compressed around a rotating axis with a coil spring. Then, when the stress to rise the body member130urged to the engaging surface is Fv, the raising force Fu urged to the body member130is represented by the following equation (1).
Fu=Fs−Fvequation (1)
Herein,
Fv=F·(cos0−μ·sin θ)  equation (2)

Where F is a folding torque, 0 is a raising angle of the engaging surface, and μ is a frictional force of the engaging surface. and
Fu=≦0  equation (3)

The equation (3) is a condition (practical range) in which does not cause the mirror assembly to rise.

As shown inFIG. 10A, in case of 60 Nm of the folding torque F, the body member130runs on at 78 degrees or less of the raising angle when the frictional force μ of the engaging surface is equal to 0.1, the body member130runs on at 73 degrees or less of the raising angle when the frictional force μ is 0.2, and the body member130runs on at 67 degrees or less of the raising angle when the frictional force μ is 0.3.

As shown inFIG. 10B, in case of 30 Nm of the folding torque F, the body member130runs on at 73 degrees or less of the raising angle when the friction force μ of the engaging surface is equal to 0.1, the body member130runs on at 66 degrees or less of the raising angle when the frictional force θ is 0.2, and the body member130runs on at 60 degrees or less of the raising angle when the frictional force μ is 0.3.

Thus, in a form of a first embodiment, θ is preferable to be 67 degrees or more and less than 90 degrees in the raising angle when the a frictional coefficient μ is 0.3. In this area, it can be satisfied with the above equation (3), a stiffness of the mirror base and the mirror housing can be enhanced, and the running on of the mirror assembly can be effectively prevented to exactly stop at the predetermined position of the mirror assembly. A relative position's relationship in a up-and-down direction between the mirror assembly and the mirror base can be maintained at a constant value.

Next, a second embodiment of the folding outer mirror relating to the present invention will be described with reference toFIG. 11andFIG. 12. The folding outer mirror of this embodiment is a manual folding outer mirror.

As shown inFIG. 11, a folding outer mirror201relating to the second embodiment has a mirror assembly providing a mirror base210, a shaft220standing upright at the mirror base210, and a rotation frame230rotating around the shaft220being a rotating axis.

A notch232is formed at a lower end of the cylindrical part231surrounding the shaft220. The notch282is designed to slant a little in a rotating direction of the mirror assembly at one end side (left side inFIG. 11) and to form a step portion to slant approximately at a right angle at the other end side (right side inFIG. 11). On the other hand, the base-side convex part211extending in an upper direction in the surrounding of the peripheral portion of the shaft220extends on an upper surface of the mirror base210. One end surface212of the base-side convex part211is engaged with an end surface233aof the step portion233of the notch232of the rotation frame230at the predetermined position such as a folded position, thus to stop the rotation frame230at the predetermined position. In this embodiment the stopper mechanism202is constituted by the notch232of the rotation frame230and the base-side convex part211of the mirror base210. The body-side engaging surface253is constituted by the end surface233aof the step portion233of the notch232, and the base-side engaging surface251is constituted by one end surface212of the base-side convex part211.

As shown inFIG. 12, the end surface233a(the body-side engaging surface253) of the step portion233of the notch232is formed to slant such that the raising angle θ relative to the rotating direction D of the mirror assembly becomes a sharp angle. The one end surface212(the base-side engaging surface251) of the base-side convex part211is formed to slant such that the raising angle θ relative to the rotating direction D of the mirror assembly is a sharp angle (the same angle as the raising angle of the body-side engaging surface253).

In such a constitution, as shown inFIG. 12B, when the end surface233aof the step portion233of the notch232contacts the one end surface212of the base-side convex part211, an outside force F is divided into a force acting direct on a plane (F1=F·sin θ) perpendicular to the end surface233and a separate force in a slip direction F2=F·cos θ. The force acting direct on a plane Fl urged to the end surface233ais smaller than the outside force F, and the contact area of the end surface is larger than one at the time of an right angle thereof. Accordingly, the contact pressure of the contact area is small, and functions as an advantageous side relative to a stiffness of the step portion233. Then, a stiffness of the stopper mechanism202becomes high.

Next, a third embodiment of the folding outer mirror relating to the present invention will be described with reference toFIG. 13andFIG. 14. The folding outer mirror of this embodiment is an electric folding outer mirror.

As shown inFIG. 13, the folding outer mirror301relating to the third embodiment has a mirror assembly providing a mirror base310, a shaft320standing upright on the mirror base310, and an electric folding unit330rotating around the shaft320being a rotation axis. The feature of this embodiment is characterized in that the raising direction of the base-side engaging surface and the body-side engaging surface of the first and second embodiments is up-and-down direction. While, the folding outer mirror of this embodiment is characterized in that the raising direction of the base-side engaging surface and the body-side engaging surface directs a radial direction of the rotation of the mirror assembly.

The body-side convex part332extending outside in the radial direction on an outside circumferential surface of a cylindrical part331is formed at a lower end of the cylindrical part331surrounding the shaft320of the electric folding unit330. As shown inFIG. 14A, the body-side convex part332is formed like an arcuate curve in section to rotate for opening at a predetermined angle. The center of the arcuate curve in section is the same as rotation center of the mirror assembly. Both end surfaces332R,332L in the circumferential direction of the body-side convex part332are respectively constituted to slant such that the raising angle 0 raising outside relative to the rotating direction D of the mirror assembly becomes a sharp angle. That is, the body-side convex part332is constituted such that a length along the outer circumference is shorter than a length along the inner circumference. Then, the body-side engaging surface353is constituted by both end surfaces332R,332L in the circumferential direction of the body-side convex part332.

The base-side convex part311extending an upper direction in the surrounding of the circumferential edge of the shaft320is formed on an upper surface of the mirror base310. The base-side convex part311is formed like an arcuate curve in section so as to surround the cylindrical part331of the electric folding unit330. The center of the arcuate curve in section is the same as a rotation center of the mirror assembly. The both end surfaces311R,311L of the base-side convex part311is constituted to slant such that the raising angle θ raising inwards relative to the rotating direction D of the mirror assembly becomes a sharp angle (the same angle as the raising angle of the body-side engaging surface353). That is, the base-side convex part311is constituted such that a length along the inner circumference is shorter than a length along the outer circumference. Then, the base-side engaging surface351is constituted by the both end surfaces311R,311L in the circumferential direction of the base-side convex part311.

In such a constitution, as shown inFIG. 14B, when the end surface332L (the body-side engaging surface353) in the circumferential direction of the body-side convex part332contacts the end surface311R (the base-side engaging surface351) in the circumferential direction of the body-side convex part332, an outside force F urged to the body-side convex part311is divided into a force acting direct on a plane F1=F·sin 0 perpendicular to the end surface332L and a separate force in a slip direction F2=F·cos θ. The force acting direct on a plane Fl urged to the end surface332L is smaller than the outside force F, and the contact area of the end surface is larger than one at the time of a right angle thereof. Accordingly, the contact pressure of the contact area is small, and functions as an advantageous side relative to a stiffness of the step portion233. Then, a stiffness of the stopper mechanism302becomes high.

Although the embodiments for carrying out the present invention has been described, the present invention is not limited to the above embodiments and various modifications can be appropriately performed without departing from the spirit and the gist of the present invention

Although the above embodiments has been described by giving an example of an electric folding outer mirror rotating the mirror assembly with electricity, it is not limited thereto. The manual folding outer mirror for manually rotating the mirror assembly is applicable in the present invention.