JP2011106551A - Light locking structure of shaft body inserted in resin bush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the cost of an assembly with a housing supporting a shaft body via a resin bush by applying to the resin bush a light locking structure of locking force preventing the shaft body from slipping out only in handling when transporting, storing and assembling. <P>SOLUTION: The light locking structure locks the light axial movement of the shaft body 6 mounted to a second member which is inserted into the resin bush 11 mounted to a first member. A diameter-contracted part 13 is formed by reducing the diameter at an end or both ends of the resin bush 11 for a fixed range, and a plurality of projections 14 for press-abutting against the outer periphery of the shaft body are formed at the inner periphery of the diameter-contracted part 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light locking structure for lightly locking a shaft body and a bush in a combination of a bush and a shaft body constituting a rotating mechanism.

  When the second member is rotatably supported with respect to the first member, a bush is fitted into the first member, and a shaft body linked to the second member is inserted into the bush. In this case, the bush is made of a resin having good slip compatibility with a metal. In this case, since the shaft body must not move in the axial direction with respect to the bush, the restricting structure is adopted. The most common method is to make the shaft body stepped and touch one side of the bush, and the other is stopped with a snap ring, or both are stopped with a snap ring.

  According to this, the shape of the shaft body becomes complicated and the cost increases, and the strength of the shaft body also decreases because the insertion groove of the snap ring is formed. Furthermore, the need for a snap ring increases the number of parts and the number of assembly steps, which increases the cost. By the way, depending on the assembly structure of the first member and the second member, it may not be necessary to restrict the movement of the shaft body. For example, a hinge mount that supports the cabin of an automobile so as to be able to roll on the frame is the same, but the cabin and the brackets attached to the frame regulate the movement in the width direction.

  In the case of such a component, the shaft body is inserted into a resin bush and the two brackets are transported and carried as one rotatable product. Therefore, if the shaft body falls out of the bush during this time, it is not good. That is, the shaft body needs to be lightly locked to the bush. As an example, it can be considered that the fitting tolerance between the bush and the shaft body is tightened to such an extent that the shaft body does not fall off, but the shaft body must be able to rotate within the bush and cannot be so tight. Thus, there is no prior art that lightly locks the shaft body to such an extent that it does not fall off the resin bush.

  In the present invention, the shaft body can be lightly locked to the bush by giving a slight additional shape to the bush.

  Under the above-described problems, the present invention provides a light weight for lightly locking the shaft body attached to the second member inserted into the resin bush attached to the first member in the axial direction. A plurality of protrusions that have a locking structure and form a small-diameter portion in which the outer diameter of one end or both ends of the bush is reduced over a certain range, and are pressed against the outer periphery of the shaft body on the inner periphery of the small-diameter portion A light locking structure for a shaft body to be inserted into a resin bush is provided.

  Moreover, in this, the means as described in claim 2 in which the resin bush is press-fitted into a metal cylinder attached to the first member, and the means as set forth in claim 3, wherein the shaft body is made of metal. According to a fourth aspect of the present invention, there is provided a means in which the metal cylinder and the resin bush are attached to a cabin or a frame, and the metal shaft is a hinge mount of a cabin attached to the frame or the cabin.

  According to the first aspect of the present invention, the outer diameter of one end or both ends of the resin bush is formed in the small diameter portion that decreases the diameter over a certain range, and the inner diameter of the small diameter portion is pushed to the outer periphery of the shaft body. By simply forming a plurality of corresponding projections, the shaft body can be lightly locked to the bush, and the structure is simple. Accordingly, both the number of parts and the number of assembly steps can be reduced to keep the cost low.

It is a perspective view before the assembly of a cabin mount. It is sectional drawing before the assembly of a cabin mount. It is a partial cross section figure of the principal part which shows the relationship between an outer cylinder, resin bushes, and a shaft body. It is a partial cross section figure of the principal part which shows the relationship between an outer cylinder, resin bushes, and a shaft body. It is explanatory drawing of the hinge mount of a track | truck. It is sectional drawing which shows the assembly of a cabin mount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this example, the hinge mount of the cabin of the automobile (truck) is taken as an example, and FIG. 5 is an explanatory view thereof, but the cabin (first member) 1 is mounted on the frame (second member) 2 with the cabin mount 3. Is supported so as to be able to turn forward. The cabin mount 3 supports the cabin 1 on the frame 2 by connecting a housing 5 including an outer cylinder 4 to the cabin 1 and attaching a shaft body (inner cylinder) 6 inserted into the outer cylinder 4 to the frame 2 by a bracket 7. It is fixed. As a result, the cabin 1 is supported in an anti-vibration manner with respect to the frame 2 and can be largely turned forward during maintenance or the like.

  FIG. 1 is a perspective view of the hinge mount 3 before assembly, FIG. 2 is a cross-sectional view of the same, and FIG. 3 is a partial cross-sectional view of the main part. A small-diameter second outer cylinder 10 is vulcanized and bonded to one outer cylinder 8 via a rubber elastic body 9, and a resin bush 11 is press-fitted into the inner periphery of the second outer cylinder 10. The shaft body 6 is inserted into the inner periphery of the shaft. In addition, as the rubber elastic body 9, it can also be considered to be a liquid-sealed type with good vibration isolation. As the resin, polyacetal, polyamide and the like excellent in strength and abrasion resistance are suitable.

  In this case, the outer diameter of one end (insertion tip side) of the resin bush 11 is reduced over a certain range, that is, if the inner diameter is left as it is, the thickness is reduced (in this example, the tapered portion 12 is formed in the middle). A plurality of protrusions 14 are formed on the inner periphery of the small-diameter portion 13. The protrusion 14 may be a stripe or a point. The formation may be simultaneous molding or separate molding. In addition, the other end side of the resin bush may be formed in the small-diameter portion 13 and the protrusion 14 may be formed on the inner periphery thereof.

  The height of the protrusion 14 at this time is set such that the tip of the protrusion 14 is pressed against the outer periphery of the shaft body 6 when the shaft body 6 is inserted. However, since there are variations in the dimensions of the second outer cylinder 10, the resin bush 11, and the shaft body 6, at least the tip of the protrusion 14 is pressed against the shaft body 6 even when the variation is large. As a result, the shaft body 6 is lightly locked by the protrusions 14 and will not come off even if a little axial external force is applied. In addition, since it is a light locking, when a full-scale rotational force is given to the shaft body 6, it does not become an unreasonable resistance.

  FIG. 3 shows a case where the gap between the inner periphery of the second outer cylinder 10 and the outer periphery of the shaft body 6 is large. In this case, the resin bush 11 hardly deforms (expands diameter), and the protrusion of the resin bush 11 14 is pressed against the shaft body 6. FIG. 4 shows a case where the gap is small. In this case, since the shaft body 6 is pressed by the entire inner periphery of the resin bush 11, the projection 14 becomes an obstacle, but the projection 14 is caused by the presence of the small diameter portion 13. Makes it easier to escape and eliminates this obstacle.

  Since the outer diameter and height of the resin bush 11 should be within this range, there is a wide tolerance for variations in molding accuracy. In addition, forming one end of the press-fitting side of the resin bush 11 in the small diameter portion 13 or the tapered portion 12 has an effect of smooth operation and reducing the pressure input when press-fitting it into the second outer cylinder 10.

  In the case of the hinge mount 3, the outer cylinder 4, the resin bush 11 and the shaft body 6 are assembled and transported, stored, and handled in units thereof. At this time, the shaft body 6 is lightened by the protrusions 14. Since it is locked, the shaft body 6 does not come off during such work.

  FIG. 6 is a cross-sectional view of the cabin mount 3 assembled, but the outer cylinder 4 is configured as one bracket on the cabin 1 side and is rotatably connected to another bracket 15 on the frame 2 side. That is, the shaft body 6 is configured as a pipe, and the bolt 16 is passed through the shaft body 6 and is fixed by the nut 17. At this time, the shaft body 6 is in contact with the wall of the bracket 15, and the bracket 15 is not deformed no matter how much the nut 17 is tightened. Note that there is a gap between the bracket including the outer cylinder 4 and the bracket 15 so that the shaft body 6 is longer than the resin bush 11, and the two move between them. It is sufficient (in this respect, it is not necessary to restrict the strict axial movement of the shaft body 6).

  The above is an example in which the present invention is applied to a hinge mount used in a cabin, but the present invention is not limited to this. When the inner cylinder is rotatably fitted in the outer cylinder via a resin bush, and it is carried and handled as a unit, it is sufficient that the axial movement of the shaft body is lightly locked. Can be used for bearings. Further, when the protrusion can be formed, the bush does not need to be made of resin, and other materials such as metal and ceramic may be used.

DESCRIPTION OF SYMBOLS 1 Cabin 2 Frame 3 Hinge mount 4 Outer cylinder 5 Housing 6 Shaft body 7 Bracket 8 1st outer cylinder 9 Rubber elastic body 10 2nd outer cylinder 11 Resin bushing 12 Tapered part 13 Small diameter part 14 Protrusion 15 Bracket 16 Bolt 17 Nut

Claims (4)

  It is a light locking structure that lightly locks the shaft body attached to the second member inserted into the resin bush attached to the first member in the axial direction, and has an outer diameter at one end or both ends of the resin bush. A shaft to be inserted into a resin bush characterized by forming a small-diameter portion having a small diameter over a certain range and forming a plurality of protrusions pressed against the outer periphery of the shaft body on the inner periphery of the small-diameter portion. Light locking structure of the body.   The light locking structure of the shaft body inserted in the resin bushing according to claim 1, wherein the resin bushing is press-fitted into a metal cylinder attached to the first member.   The light locking structure of the shaft body inserted in the resin bush according to claim 1 or 2, wherein the shaft body is made of metal.   4. A light locking structure for a shaft inserted into a resin bush according to claim 3, wherein the metal cylinder and the resin bush are attached to the cabin or the frame, and the metal shaft is a hinge mount of the cabin attached to the frame or the cabin. .