JP2008151289A - Sliding bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding bearing capable of shaping its exterior surface side without using an outer mold which is divided into sections corresponding to the number of slits to be shaped by the outer mold and facilitating manufacturing and reducing cost. <P>SOLUTION: The sliding bearing 1 comprises a bearing body 11, slits 14 and 15 extended from one end face 12 in the axial direction A of the bearing body 11 to the other end face 13 in the axial direction A of the bearing body 11, slits 16, 17, and 18 extended from the other end face 13 of the bearing body 11 to one end face 12 of the bearing body 11, a sliding surface 19 which is formed inside the bearing body 11 and partially partitioned by the slits 14 to 18, mounting grooves 21 formed on the outer surface 20 of the bearing body 11, and elastic rings 22 which are radially projected outwardly from the outer surface 20 of the bearing body 11 and fitted into the mounting grooves 21 so as to contract the diameter of the bearing body 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bearing mechanism including a slide bearing interposed between a shaft such as a rack shaft and a housing in order to support, for example, a rack shaft of an automobile so as to be movable.

JP 2004-347105 A

  A sliding bearing made of a synthetic resin is used as a bearing for a rack shaft that supports a rack shaft for steering of an automobile so that the rack shaft can move directly.

  Sliding bearings have the advantages of lower cost and better vibration absorption than rolling bearings, but they require an appropriate clearance (bearing clearance) between the sliding bearing and the rack shaft, so they occur in the rack shaft. There is a problem that a collision noise is generated between the rack shaft and the sliding bearing due to the vibration and is transmitted as an unpleasant sound to a person driving the automobile. If the clearance between the slide bearing and the rack shaft is reduced to suppress the occurrence of this collision noise, the friction torque increases, and the difference between the friction torque at the start of linear motion and during the linear motion increases and the rack is increased. It becomes a factor that hinders the stability of the friction torque, such as a fluctuation of the friction torque during the linear motion due to a stick-slip phenomenon or the like due to an outer diameter error of the shaft.

  In addition, the rack shaft is supported by the housing through a sliding bearing so as to be able to move directly, but the roundness of the inner diameter of the housing is usually not so high, and a sliding bearing made of synthetic resin is press-fitted into the housing. When fixed, the sliding bearing is distorted due to the roundness of the inner diameter of the housing, resulting in a difference in clearance from the rack shaft, which also inhibits the stability of the friction torque.

  In Patent Document 1, it is possible to eliminate the collision noise with the rack shaft, reduce the linear frictional resistance, reduce the difference in the linear frictional resistance between when the linear motion starts and during linear motion, and Stable linear motion friction resistance can be obtained without being affected by the diameter error and the roundness of the inner diameter of the housing. Thus, the rack shaft can be supported smoothly and the rack shaft can be moved more smoothly. Resin-type plain bearings that can be made have been proposed.

  A sliding bearing proposed in Patent Document 1 includes a cylindrical bearing body, and a plurality of slits extending from one axial end surface of the bearing main body toward the other axial end surface of the bearing main body. The other slit extending from the other end surface of the bearing body toward the one end surface of the bearing body, the sliding surface provided inside the bearing body, the mounting groove provided on the outer surface of the bearing body, An elastic ring that partially protrudes radially from the outer surface of the bearing body and that is fitted in the mounting groove so as to reduce the diameter of the bearing body. When integrally molding with resin, the mounting groove is provided on the outer surface of the bearing body. As a result, the outer mold that forms the outer surface of the bearing body cannot be removed in the axial direction. Multiple outer molds divided After need be by molding is removed from the bearing body is pulled out the divided plurality of outer mold radially outward.

  By the way, in the sliding bearing proposed in Patent Document 1, as a result of one and the other slits extending radially in the radial direction, in order to pull out the outer mold from the bearing body after molding and remove it from the bearing body, As a result of requiring the outer mold divided into the number corresponding to the number of slits to be formed by the outer mold, the manufacturing becomes complicated and the cost increases.

  The present invention has been made in view of the above points, and the object of the present invention is to provide an outer surface side without using an outer mold divided into a number corresponding to the number of slits to be formed by the outer mold. It is an object of the present invention to provide a plain bearing that can be molded and thus can be easily manufactured and can reduce costs.

  A sliding bearing according to the present invention includes a cylindrical bearing body and a plurality of ones provided on the bearing body and extending from one axial end surface of the bearing main body toward the other axial end surface of the bearing main body. And the other slit extending from the other end surface of the bearing body toward the one end surface of the bearing body, and the inner slit of the bearing body and the center of the shaft by the both slits. A sliding surface partially divided in the surrounding direction, at least one mounting groove provided on the outer surface of the bearing body, and partially protruding in the radial direction from the outer surface of the bearing body and reducing the diameter of the bearing body And at least one of the plurality of slits is divided by a virtual diameter line passing through the center of the bearing body. The remaining one of the plurality of slits is separated by a virtual diameter line passing through the center of the bearing body. At least one slit provided in one semi-cylindrical part has a width in a direction parallel to the virtual diameter line from the inside to the outside of one semi-cylindrical part of the bearing body. It extends in the direction perpendicular to the virtual diameter line so that it becomes the same width or gradually increases from the inside to the outside of one semi-cylindrical portion of the bearing body, The remaining one slit provided in the semi-cylindrical portion has a width in the direction parallel to the virtual diameter line so that the width is the same from the inside to the outside of the other semi-cylindrical portion of the bearing body, or the width is the bearing. Inside the other semi-cylindrical part of the main body To gradually increase brought toward its Luo outward, it extends in a direction perpendicular to the virtual diametrical line.

  According to the sliding bearing of the present invention, at least one of the slits provided in the one semi-cylindrical portion has a width in a direction parallel to the virtual diameter line from the inside to the outside of the one semi-cylindrical portion of the bearing body. Extending in the direction perpendicular to the virtual diameter line so that the width becomes the same width or gradually increases from the inside to the outside of one semi-cylindrical portion of the bearing body, One of the remaining slits provided in the semi-cylindrical part of the bearing is such that the width in the direction parallel to the virtual diameter line is the same from the inside to the outside of the one semi-cylindrical part of the bearing body, or the width is Since it extends in the direction orthogonal to the virtual diameter line so that it gradually increases from the inside to the outside of the other half-cylindrical portion of the bearing body, Two divisions with the outer mold for the other semi-cylindrical part Even if the bearing body is molded with both slits using the outer mold, the two separated outer molds can be easily pulled out from the bearing body and removed from the bearing body after molding. The outer surface side can be molded without using an outer mold divided into the number corresponding to the number of slits to be formed in the mold, and a sliding bearing having a plurality of slits and mounting grooves can be easily manufactured to reduce costs. obtain.

  In the sliding bearing of the present invention, at least one slit provided in one semi-cylindrical portion is flat in the direction from the inner side to the outer side of the one semi-cylindrical portion and extends in parallel with each other. Even though it is defined by a pair of flat walls, one flat wall of one semi-cylindrical portion that extends flat in the direction from the inside to the outside of one semi-cylindrical portion and from the inside to the outside of one semi-cylindrical portion Even if it is defined by the other flat wall of one semi-cylindrical portion that is gradually separated from the flat wall as it goes, and further extends toward the outside from one semi-cylindrical portion, It may be defined by a pair of flat walls of one semi-cylindrical portion that is gradually separated from each other and extends flat.

  The remaining one slit provided in the other semi-cylindrical portion is defined by a pair of flat walls of the other semi-cylindrical portion that are flat in the direction from the inner side to the outer side of the other semi-cylindrical portion and extend parallel to each other. However, one flat wall of the other semi-cylindrical portion that extends flat in the direction from the inner side to the outer side of the other semi-cylindrical portion, and gradually from the flat wall as it goes from the inner side to the outer side of the other semi-cylindrical portion. And the other flat wall of the other semi-cylindrical portion that extends flatly apart from each other, and further, gradually flatten away from each other as it goes from the inside to the outside of the other semi-cylindrical portion. You may be prescribed | regulated by a pair of flat wall of the other semi-cylinder part to extend.

  In the sliding bearing of the present invention, when the bearing main body to which the elastic ring is attached is inserted into the inner peripheral surface of the housing, the elastic ring partially protruding from the outer peripheral surface of the bearing main body is It is elastically deformed with a tightening margin, and the elastic deformation can absorb dimensional errors such as the roundness of the inner diameter of the housing. Further, the bearing body of the present invention, which can be reduced in diameter by a slit having an open end with respect to both end faces of the bearing body, has a sliding surface on a rack shaft which is reduced in diameter by an elastic ring and inserted into the inside thereof. Since the clearance between the rack shaft and the rack shaft can be reduced to zero, the collision with the rack shaft can be eliminated. As a result, the generation of the collision noise transmitted as an unpleasant noise can be eliminated, and the linear motion can be achieved. It is possible to reduce the difference between the linear frictional resistance at the start and the linear motion, and to absorb the outer diameter dimension error of the rack shaft, thereby obtaining a stable linear frictional resistance.

  In a preferred example, the slide bearing is mounted in a housing through which a rack shaft or the like passes. However, the outer diameter of the elastic ring fitted in the mounting groove depends on the elastic coefficient of the elastic ring. Although a thing larger by about 0.3 mm to 1.0 mm than the diameter of the inner peripheral surface can be presented as a preferred example, the inner diameter is about 0.3 mm to 1.0 mm smaller than the diameter of the bottom surface of the mounting groove. In short, the clearance between the sliding surface and the shaft such as the rack shaft is obtained by tightening the shaft such as the rack shaft with an appropriate elastic force through the sliding surface with respect to the inner peripheral surface of the housing. It is only necessary to project from the outer peripheral surface of the bearing main body and reduce the diameter of the bearing main body so as to make zero the diameter. Specifically, at least the outer diameter is larger than the diameter of the inner peripheral surface of the housing. If the inner diameter is smaller than the diameter of the bottom of the groove Good.

  Any of the elastic rings may be a so-called O-ring having a circular cross section, but may be another X-shaped cross-section, a U-shaped cross-section or a trapezoidal ring, and the like. For example, any of natural rubber, synthetic rubber, and thermoplastic synthetic resin having elasticity, for example, polyester elastomer may be used.

  In the present invention, the bearing body may be provided with a plurality of one and other slits, and the one and other slits may be alternately arranged in the direction around the axis, and each sliding surface May be provided on the inner side of the bearing body at a position separated from the both end faces of the bearing body by a predetermined distance in the axial direction, and in a preferred example, the outer peripheral surface of the bearing body is spaced apart from each other in the axial direction. At least two mounting grooves are provided, and each mounting groove partially protrudes from the outer peripheral surface of the bearing body, and an elastic ring is fitted so as to reduce the diameter of the bearing body. An axial center portion of the sliding surface is located between the grooves, and the sliding surface may be provided on the inner side of the bearing body between the two mounting grooves in the axial direction. Shaft over mounting groove It may be provided on the inside of the body.

  The elastic ring fitted in the mounting groove preferably has a volume larger than the volume of the mounting groove. The elastic ring does not need to be arranged closely to the bearing body without a gap in the mounting groove, and may be fitted in the mounting groove with a slight gap with respect to the bearing body, and the diameter from the outer peripheral surface of the bearing body The part of the elastic ring that partially protrudes in the direction may be deformed when it is properly pressed by the housing to completely fill the mounting groove, or when it is normally pressed by the housing in this way However, when the housing is eccentrically deviated from the normal position with respect to the rack shaft due to an unintended external force and partially pressed strongly by the housing, the bearing body is pressed excessively. It may be deformed at the site to completely fill the groove to increase rigidity, thereby countering unintentional eccentricity of the housing.

  The slide bearing preferably has a clearance having a width of 0.3% to 10% of the maximum radial thickness of the bearing body at a portion that becomes a free end with respect to the housing, and the inner peripheral surface of the housing and the free end. It is generated between the outer peripheral surface of the bearing main body at the part to be a part. If the clearance is less than 0.3%, there is a risk that the housing will easily come into contact with the bearing body and generate abnormal noise when the housing is decentered from the normal position with respect to the rack shaft due to unintended external force. If the clearance is larger than 10%, the housing may be easily decentered from the normal position with respect to the rack shaft by an unintended external force, which may reduce the alignment effect of the bearing mechanism. As a result, contact of the housing with the bearing main body can be avoided, and the housing can be reliably held at a normal position with respect to the rack shaft.

  In the sliding bearing according to the present invention, in order to ensure a large flow of air outside the housing with respect to the inside of the housing in the axial movement of the rack shaft, a ventilation groove for communicating the inside of the housing with the outside of the housing is provided on the outer surface side of the bearing body or It may be provided on the inner surface side.

  In a preferred example, the inner side of the bearing body extends from one end surface of the bearing body to one end in the axial direction of the sliding surface and gradually decreases in diameter, and from the other end surface of the bearing body to the sliding surface. The other tapered surface extending to the other end in the axial direction and gradually decreasing in diameter, wherein one tapered surface has an axial length longer than the axial length of the other tapered surface. The one taper surface may have a taper angle larger than the taper angle of the other taper surface, and according to the slide bearing having such a taper surface, the bearing body from the one taper surface side. As a result, the assembly man-hours can be greatly reduced.

  In the present invention, the bearing main body is integrally molded from a synthetic resin, and the synthetic resin forming the bearing main body is a thermoplastic synthetic resin such as polyacetal resin, polyamide resin, polyethylene resin and tetrafluoroethylene resin. It can be mentioned as a preferred example.

  According to the present invention, the outer surface side can be molded without using the outer mold divided into the number corresponding to the number of slits to be formed by the outer mold, and thus the manufacturing is easy and the cost can be reduced. A planable sliding bearing can be provided.

  Hereinafter, the present invention and preferred embodiments thereof will be described with reference to the drawings. The present invention is not limited to these examples.

  1 to 4, the sliding bearing 1 of this example is interposed between a cylindrical inner peripheral surface 3 of a housing 2 and a cylindrical outer peripheral surface 5 of a rack shaft 4 that is inserted into the housing 2. It has become so.

  The sliding bearing 1 is provided in the cylindrical bearing body 11 and the one end face 12 in the axial direction A of the bearing body 11 toward the other end face 13 in the axial direction A of the bearing body 11. Two sets of two slits 14 and 15 in total, each of which extends, and two slits 14 and 15 provided in the bearing body 11 and extending from the other end face 13 of the bearing body 11 toward the one end face 12 of the bearing body 11 A set of three slits 16, 17 and 18 in total, and a cylindrical sliding surface provided inside the bearing body 11 and partially divided in the direction B around the axis by the slits 14 to 18 19 and at least one provided on the outer surface 20 of the bearing body 11, in this example, two mounting grooves 21 and the outer surface 20 of the bearing body 11 partially protrude radially outward and the bearing body 11 is shrunk. Diameter And comprising an elastic ring 22 which is fitted to each of the urchin mounting groove 21.

  The bearing body 11 integrally having a flange 24 which is divided in the direction B by the slits 14 and 15 and is fitted into the annular locking groove 23 of the housing 2 has a sliding surface 19 inside thereof. In addition, it extends in the axial direction A from the end surface 12 toward the end surface 13 and gradually contracts in diameter to terminate at one edge of the sliding surface 19, and is divided in the direction B by the slits 14 and 15. The taper surface 31 extends in the axial direction A from the end surface 13 toward the end surface 12 and gradually decreases in diameter to terminate at the other annular edge of the sliding surface 19, and in the direction B by the slits 16 to 18. It includes a divided tapered surface 32 and a ventilation groove 33 extending in the axial direction A from the end surface 12 and connected to one end in the axial direction A of the slits 16, 17 and 18. One edge of Are divided in the direction B by the slits 14 and 15 and the ventilation grooves 33, the other edge of the sliding surface 19 is divided in the direction B by the slits 16 18.

  At least one of the plurality of slits 14 and 15 that open in the end surface 12 and extend in the axial direction A beyond the mounting groove 21 on the end surface 13 side, in this example, two slits 14. Each is provided in one semi-cylindrical portion 42 of the bearing body 11 which is divided by a virtual diameter line 41 passing through the center O of the bearing body 11, and one of the remaining ones of the plurality of slits 14 and 15. Each of the two slits 15 in this example is provided in the other semi-cylindrical portion 43 of the bearing body 11 that is divided by a virtual diameter line 41 passing through the center O of the bearing body 11.

  Each of the two slits 14 provided in the semi-cylindrical portion 42 has a width D in the direction C parallel to the virtual diameter line 41 gradually increasing from the inner side 44 to the outer side 45 of the semi-cylindrical portion 42. As shown, the slits 14 extend in a direction E perpendicular to the virtual diameter line 41, and each of the slits 14 is in the direction E perpendicular to the virtual diameter line 41 from the inner side 44 to the outer side 45 of the semi-cylindrical portion 42. The flat wall 46 of the semi-cylindrical portion 42 that extends flatly in the direction toward the flat surface, and the flat surface of the semi-cylindrical portion 42 that gradually extends away from the flat wall 46 as it goes from the inner side 44 to the outer side 45 of the semi-cylindrical portion 42. It is defined by the wall 48.

  Each of the two slits 14 is symmetrically arranged with an angle of about 45 ° with respect to the orthogonal virtual diameter line 49 that passes through the center O and is orthogonal to the virtual diameter line 41.

  Each of the two slits 15 provided in the semi-cylindrical portion 43 has the width D in the direction C parallel to the virtual diameter line 41 in the same manner as each of the two slits 14. The slits 15 extend in the direction E perpendicular to the virtual diameter line 41 so as to gradually increase from the first to the outer side 55, and each of the slits 15 is in the direction E perpendicular to the virtual diameter line 41. The flat flat wall 56 of the semi-cylindrical portion 43 that extends flat in the direction from the inner side 54 to the outer side 55 of the semi-cylindrical portion 43 and gradually from the flat wall 56 toward the outer side 55 from the inner side 54 of the semi-cylindrical portion 43. And the flat wall 58 of the semi-cylindrical portion 43 that extends away from each other.

  Each of the two slits 15 is symmetrically arranged with an angle of about 45 ° with respect to the orthogonal virtual diameter line 49 that passes through the center O and is orthogonal to the virtual diameter line 41, similarly to each of the two slits 14. In addition, the virtual diameter line 41 is symmetrically arranged with respect to each of the two slits 14.

  Each of the two slits 16 provided in the semi-cylindrical portion 42 is in a direction E perpendicular to the virtual diameter line 41 and from the inner side 44 to the outer side 45 of the semi-cylindrical portion 42 of the bearing body 11. The width d in the direction C parallel to the virtual diameter line 41 extends to be the same width, and each of the slits 16 is flat in the direction E orthogonal to the virtual diameter line 41 and parallel to each other. Are defined by a pair of flat walls 61 of the semi-cylindrical portion 42 extending in the direction B, are arranged between the two slits 14 in the direction B, and are symmetrical with respect to the orthogonal virtual diameter line 49 at an angle of approximately 20 °, respectively. It is arranged in.

  Each of the two slits 17 provided in the semi-cylindrical portion 43 is in a direction E perpendicular to the virtual diameter line 41 and from the inner side 54 to the outer side 55 of the semi-cylindrical portion 43 of the bearing body 11. The width d in the direction C parallel to the virtual diameter line 41 extends to be the same width, and each of the slits 17 is flat in the direction E perpendicular to the virtual diameter line 41 and parallel to each other. Are defined by a pair of flat walls 62 of the semi-cylindrical portion 43 extending in the direction B, are arranged between the two slits 15 in the direction B, and are symmetrical with respect to the orthogonal virtual diameter line 49 at an angle of approximately 20 °, respectively. It is arranged in.

  Each of the two slits 18 provided at the boundary between the semi-cylindrical portion 42 and the semi-cylindrical portion 43 is in a direction C parallel to the virtual diameter line 41, and the semi-cylindrical portion 42, the semi-cylindrical portion 43, The width d in the direction E perpendicular to the virtual diameter line 41 is the same in the direction from the inner side 44 and 54 to the outer side 45 and 55 of the semi-cylindrical portions 42 and 43 of the bearing body 11 at the boundary portion of Each of the slits 18 is defined by a pair of flat walls 63 of semi-cylindrical portions 42 and 43 that are flat in a direction C parallel to the virtual diameter line 41 and extend parallel to each other. Each of the slits 18 is arranged symmetrically on the virtual diameter line 41 and at an angle of about 90 ° with respect to the orthogonal virtual diameter line 49.

  The ventilation groove 33 connected to each one end of the slit 16 in the axial direction A is connected to the bottom surface 64 and the flat wall 61 and is flat in the direction E and extends in parallel with each other. The ventilation groove 33 connected to each one end in the axial direction A of the slit 17 is connected to the bottom surface 66 and the flat wall 62 and is flat in the direction E and parallel to each other. A ventilation groove 33 defined by a pair of flat walls 67 extending in the direction of the slit 18 and connected to one end in the axial direction A of the slit 18 is connected to the bottom surface 68 and the flat wall 63 and It is defined by a pair of flat walls 69 extending in parallel to each other in the same direction as the flat wall 63.

  The bearing body 11 including the flange portion 24 is integrally molded from a synthetic resin, for example, a thermoplastic synthetic resin such as a polyacetal resin or a polyamide resin.

  Two mounting grooves 21 provided on the outer surface 20 of the bearing body 11 so as to be separated from each other in the axial direction A are defined by three annular projections 71, 72 and 73 on the outer surface 20 side of the bearing body 11. The diameters of the outer surface 20 of the bearing body 11 at the protrusions 71, 72 and 73 are equal to each other, but smaller than the diameter of the inner peripheral surface 3 of the housing 2, and the outer surface 20 of the bearing body 11 at the protrusions 71, 72 and 73 and the housing. An annular gap (clearance) 74 is formed between the inner peripheral surface 3 and the inner peripheral surface 3.

  Each elastic ring 22 made of an O-ring is not fitted on the inner circumferential surface 3 of the housing 2, but has an outer diameter larger than the diameter of the inner circumferential surface 3 of the housing 2 while being fitted in the mounting groove 21. And has an inner diameter smaller than the diameter of the bottom surface 75 of the mounting groove 21 in a state where it is not mounted on the inner peripheral surface 3 of the housing 2 and is not mounted on the mounting groove 21. Thus, each of the elastic rings 22 that protrude partially from the outer surface 20 of the projections 71, 72, and 73 of the bearing body 11 and that are fitted in the mounting groove 21 so as to reduce the diameter of the bearing body 11 is fitted. It has a volume larger than the volume of the mounting groove 21 to be mounted, and even if it is tightened and deformed to fill the mounting groove 21 without a gap, it partially protrudes from the outer surface 20.

  Each elastic ring 22 is fitted to the inner peripheral surface 3 of the housing 2 with a tightening margin at the outer peripheral surface, and the bearing body 11 has a gap 74 between the outer surface 20 and the inner peripheral surface 3 of the housing 2. The rack shaft 4 is arranged on the inner peripheral surface 3 of the housing 2 and the rack shaft 4 is movably clamped in the axial direction A by the elastic force of the elastic ring 22 via the sliding surface 19 to Mounted on surface 5.

  The rack shaft 4 that is movable in the axial direction A is connected to the steering wheel on the one hand and to the wheel on the other side via a connecting mechanism, and such a connecting mechanism is known and will not be described.

  In the sliding bearing 1 described above, the elastic ring 22 is fitted into the mounting groove 21 of the outer surface 20 of the bearing main body 11, so that the bearing main body 11 having the slits 14 to 18 is reduced in diameter by the elastic compressive force of the elastic ring 22. Thus, the sliding bearing 1 in a state where the diameter of the bearing body 11 is reduced is disposed in the housing 2, and then the rack shaft 4 is inserted inside the bearing body 11, whereby the bearing body 11 has the elastic ring 22. While the diameter of the rack shaft 4 is increased by the slits 14 to 18 against the elastic compressive force, the rack shaft 4 is tightened by the sliding surface 19 with the elastic compressive force of the elastic ring 22 on the outer peripheral surface 5. The outer peripheral surface is brought into contact with the inner peripheral surface 3 of the housing 2 with a tightening margin, and the flange portion 24 fitted in the annular locking groove 23 of the housing 2 is used. Bearing 1 Ri will be positioned with respect to the housing 2.

  Therefore, the clearance between the sliding surface 19 and the outer peripheral surface 5 of the rack shaft 4 becomes zero, and the collision between the bearing body 11 and the rack shaft 4 can be eliminated, and as a result, it is transmitted to the driver as an unpleasant sound. No impact sound is generated, and the elastic ring 22 fitted in the mounting groove 21 of the bearing body 11 has a tightening margin with respect to the inner peripheral surface 3 of the housing 2, so that the elastic ring 22 is elastically deformed and the elastic deformation is performed. Thus, dimensional errors such as the roundness of the inner diameter of the housing 2 can be absorbed.

  Also in the slide bearing 1, the inside of the housing 2 and the outside of the housing 2 can be communicated with each other through the slits 16, 17 and 18 and the ventilation groove 33, so that the rack shaft 4 moves in the axial direction A with respect to the housing 2. The entrance and exit of air outside the housing 2 can be secured.

  In addition, in the sliding bearing 1, the two slits 14 extend in the direction E so that the width D gradually increases from the inner side 44 to the outer side 45 of the semicylindrical portion 42, and the two slits 15 are Since the width D extends in the direction E so as to gradually increase from the inner side 54 to the outer side 55 of the semi-cylindrical portion 43, the outer die for the semi-cylindrical portion 42 and the outer die for the semi-cylindrical portion 43. Even if the outer surface 20 side of the bearing body 11 is molded together with the slits 14 and 15 with the two divided outer molds, the outer molds are easily pulled out in the direction E in the direction E after the molding. Can be removed. In the sliding bearing 1, the inner surface side including the sliding surface 19 of the bearing body 11 and the slits 16, 17 and 18 and the ventilation groove 33 are formed on the outer surface 20 side of the bearing body 11, and the slits 16, 17 and 18 and the ventilation groove. The molding core having a projection corresponding to the groove 33 is formed in the outer mold and molded by drawing the core from the bearing body 11 toward the end face 13 after molding.

  Therefore, in order to manufacture the sliding bearing 1, two outer molds, that is, the outer mold for the semi-cylindrical portion 42 and the outer mold for the semi-cylindrical section 43 that form the outer surface 20 side of the bearing body 11, and the inner surface of the bearing body 11. Therefore, it is only necessary to prepare a mold with a core that molds the side, and thus the slide bearing 1 having the plurality of slits 14 and 15 and the mounting groove 21 can be easily manufactured, and the cost can be reduced. .

  In the sliding bearing 1 described above, the ventilation groove 33 extends in the axial direction A from the end surface 12 and is connected to one end in the axial direction A of the slits 16, 17 and 18, and is provided inside the bearing body 11. Instead of or together with this, as shown in FIGS. 5 to 8, it may be provided outside the bearing body 11. That is, in the sliding bearing 1 shown in FIGS. 5 to 8, the ventilation groove 81 extends in the axial direction A from the end face 12 and is connected to one end of the slits 16 and 17 in the axial direction A and the flange 24. And the ventilation groove 81 is connected to the bottom surface 82 and the flat walls 61 and 62 and is flat in the direction E and extends in parallel with each other. And a pair of flat walls 83.

  The figure is provided between the cylindrical inner peripheral surface 3 of the housing 2 and the cylindrical outer peripheral surface 5 of the rack shaft 4 inserted into the housing 2 and has a ventilation groove 81. Also in the sliding bearing 1 shown in FIGS. 5 to 8, the collision between the bearing body 11 and the rack shaft 4 can be eliminated similarly to the sliding bearing 1 described in FIGS. 1 to 4, resulting in an unpleasant sound for the driver. No transmitted collision noise is generated, and dimensional errors such as the roundness of the inner diameter of the housing 2 can be absorbed by the elastic deformation of the elastic ring 22, and the slits 16 and 17 and the ventilation between the inside of the housing 2 and the outside of the housing 2 are ventilated. Since the air can be communicated via the groove 81, the movement of the rack shaft 4 in the axial direction A can ensure the flow of air outside the housing 2 with respect to the inside of the housing 2, and the projection for the ventilation groove 81 is provided. Semi-cylindrical part 42 Even if the outer surface side of the bearing main body 11 is molded together with the slits 14 and 15 and the ventilation groove 81 with two outer molds of the outer mold and the outer mold for the semi-cylindrical portion 43, it is easy after molding. Both outer molds can be pulled out in the direction E in opposite directions and removed from the bearing body 11.

  In the sliding bearing 1 shown in FIGS. 1 to 4, the ventilation groove 33 is provided inside the bearing body 11 on the end face 12 side so as to communicate with the slits 16, 17 and 18, and the sliding bearing shown in FIGS. 5 to 8. 1, the ventilation groove 81 is provided outside the bearing body 11 and in communication with the slits 16 and 17 on the end face 12 side, but instead of or together with this, as shown in FIGS. 9 to 12, The ventilation grooves 85 and 86 may be provided outside the bearing body 11 and on the end face 13 side so as to communicate with the slits 14 and 15. That is, in the plain bearing 1 shown in FIGS. 9 to 12, the ventilation groove 85 extends from the end surface 13 in the axial direction A and is connected to each of the other ends of the slit 14 in the axial direction A and The ventilation groove 85 provided on the outer surface 20 is connected to the inclined bottom surface 87, the flat wall 88 connected to the flat wall 46 and extending flat in the direction E, and the flat wall 48. Defined by a flat wall 89 extending in the direction E and gradually becoming deeper from the end face 13 toward the end face 12, and the ventilation groove 86 extends in the axial direction A from the end face 13. The slit 15 is connected to each of the other ends in the axial direction A of the slit 15 and is provided on the outer surface 20 of the bearing body 11. The ventilation groove 86 is connected to the inclined bottom surface 90 and the flat wall 56. And flat in direction E A flat wall 91 which are, defined by a flat wall 92 extending in the direction E along with being connected to the flat wall 58, is gradually deeper him to towards the end surface 12 from the end face 13.

  The housing 2 is interposed between the cylindrical inner peripheral surface 3 of the housing 2 and the cylindrical outer peripheral surface 5 of the rack shaft 4 inserted into the housing 2, and has ventilation grooves 85 and 86. The sliding bearing 1 shown in FIGS. 9 to 12 can eliminate the collision between the bearing body 11 and the rack shaft 4 in the same manner as the sliding bearing 1 described in FIGS. 1 to 4 and FIGS. 5 to 8. As a result, no collision sound is transmitted to the driver as an unpleasant sound, and the elastic deformation of the elastic ring 22 can absorb dimensional errors such as the roundness of the inner diameter of the housing 2, and the inside of the housing 2 and the outside of the housing 2 can be absorbed. Can be communicated with each other through the slits 14 and 15 and the ventilation grooves 85 and 86, so that the movement of the air outside the housing 2 with respect to the inside of the housing 2 can be secured in the movement of the rack shaft 4 in the axial direction A. For ventilation The two slits 14 and 15 are divided into two outer molds: an outer mold for the semi-cylindrical portion 42 having a projection for 85 and an outer mold for the semi-cylindrical portion 43 having a projection for the ventilation groove 86. In addition, even if the outer surface side of the bearing body 11 is molded together with the ventilation grooves 85 and 86, both the outer molds can be easily pulled out in the direction E and removed from the bearing body 11 after molding. it can.

  Even though the slits 14 and 15 have the same width from the inner side 44 and 54 of the semi-cylindrical portions 42 and 43 of the bearing body 11 toward the outer side 45 and 55, they are parallel to each other in the direction E. May be defined by a pair of flat walls of the semi-cylindrical portions 42 and 43 extending further in the direction from the inner side 44 and 54 to the outer side 45 and 55. It may be defined by a pair of flat walls of the cylindrical portions 42 and 43.

It is II sectional view explanatory drawing shown in FIG. 2 of a sliding bearing in the preferable example of this invention. It is right side explanatory drawing of the slide bearing of the example shown in FIG. It is a left side explanatory view of the slide bearing of the example shown in FIG. FIG. 2 is an explanatory plan view of a sliding bearing in the example shown in FIG. 1. FIG. 7 is a cross-sectional explanatory view taken along the line VV shown in FIG. 6 of the sliding bearing in a preferred example of the present invention. It is right side explanatory drawing of the sliding bearing of the example shown in FIG. It is left side explanatory drawing of the slide bearing of the example shown in FIG. FIG. 6 is an explanatory plan view of a sliding bearing in the example shown in FIG. 5. FIG. 11 is a cross-sectional explanatory view taken along line IX-IX of FIG. 10 showing a sliding bearing in a preferred example of the present invention. It is right side explanatory drawing of the slide bearing of the example shown in FIG. FIG. 10 is a left side explanatory view of the slide bearing of the example shown in FIG. 9. FIG. 10 is an explanatory plan view of a plain bearing in the example shown in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sliding bearing 11 Bearing main body 12, 13 End surface 14, 15, 16, 17, 18 Slit 19 Sliding surface 20 Outer surface 21 Mounting groove 22 Elastic ring

Claims (7)

  A cylindrical bearing body, a plurality of slits provided on the bearing body and extending from one axial end surface of the bearing main body toward the other axial end surface of the bearing main body, and the bearing main body And the other slit extending from the other end surface of the bearing body toward the one end surface of the bearing body, and provided in the bearing body and partially in the direction around the axis by both slits. The separated sliding surface, at least one mounting groove provided on the outer surface of the bearing body, and a part of the bearing body that protrudes radially from the outer surface of the bearing body and fits in the mounting groove so as to reduce the diameter of the bearing body. One half cylindrical portion of the bearing body that is divided by a virtual diameter line passing through the center of the bearing body. The remaining one of the plurality of slits is provided in the other semi-cylindrical portion of the bearing body that is divided by an imaginary diameter line passing through the center of the bearing body. At least one of the slits provided in the semi-cylindrical part has a width in a direction parallel to the virtual diameter line so that the width is the same from the inside to the outside of the one semi-cylindrical part of the bearing body, or the width is One of the remaining portions provided in the other semi-cylindrical part extends in a direction perpendicular to the virtual diameter line so that it gradually increases from the inside to the outside of one semi-cylindrical part of the bearing body. The slit in the direction parallel to the virtual diameter line has the same width from the inside to the outside of the other semi-cylindrical portion of the bearing body or from the inside of the other half-cylindrical portion of the bearing body. Gradually toward the outside As increases, the sliding bearing extending in a direction perpendicular to the virtual diametrical line.   At least one slit provided in one semi-cylindrical portion is defined by a pair of flat walls of one semi-cylindrical portion that are flat in the direction from the inside to the outside of the one semi-cylindrical portion and extend parallel to each other. The plain bearing according to claim 1.   At least one slit provided in one semi-cylindrical portion includes one flat wall of one semi-cylindrical portion that extends flat in the direction from the inside to the outside of one semi-cylindrical portion, and one semi-cylindrical portion. The sliding bearing according to claim 1, wherein the sliding bearing is defined by the other flat wall of one semi-cylindrical portion that gradually extends away from the flat wall as it goes from the inside to the outside.   At least one of the slits provided in one semi-cylindrical portion is a pair of flat walls of one semi-cylindrical portion that extends flatly away from each other as it goes from the inside to the outside of the one semi-cylindrical portion. The plain bearing according to claim 1, defined by   The remaining one slit provided in the other semi-cylindrical portion is defined by a pair of flat walls of the other semi-cylindrical portion that are flat in the direction from the inner side to the outer side of the other semi-cylindrical portion and extend parallel to each other. The sliding bearing according to any one of claims 1 to 4.   The remaining one slit provided in the other semi-cylindrical portion includes one flat wall of the other semi-cylindrical portion that extends flat in the direction from the inside to the outside of the other semi-cylindrical portion, and the other half-cylindrical portion. The sliding bearing according to any one of claims 1 to 4, wherein the sliding bearing is defined by the other flat wall of the other semi-cylindrical portion that gradually extends away from the flat wall as it goes from the inside to the outside. .   One of the remaining slits provided in the other semi-cylindrical portion is a pair of flat walls of the other semi-cylindrical portion that are gradually separated from each other as they go from the inside to the outside of the other semi-cylindrical portion. The plain bearing according to any one of claims 1 to 4, wherein the plain bearing is defined.

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