JP2005254880A - Rack guide for rack pinion type steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rack guide capable of eliminating generation of abnormal noise attributable to set-in of a coil spring by omitting the coil spring, and a rack pinion type steering device using the rack guide. <P>SOLUTION: The rack guide 10 used for the rack pinion type steering device 1 comprises a rack guide body 23 having a semi-cylindrical recessed surface 21 slidably in contact with a semi-cylindrical outer circumferential surface 15 of a rack bar 9 and a bearing surface 22 under the pressure F toward the rack bar 9, an annular elastically-deformable member 24 arranged on the bearing surface 22 side of the rack guide body 23, and an annular pressing member 25 to apply the pressure F toward the rack bar 9 to the elastically-deformable member 24. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rack and pinion type used in a vehicle such as an automobile in which a pinion is rotated in conjunction with a rotating operation of a handle and a rack bar having rack teeth meshing with the pinion is reciprocated to perform steering. The present invention relates to a rack guide for a steering device.

Japanese Utility Model Publication No.58-19873

  A rack and pinion type steering device is usually arranged in a gear case, a pinion rotatably supported by the gear case via a pinion shaft, a rack bar formed with rack teeth meshing with the pinion, and a gear case. And a rack guide that slidably supports the rack bar, and a coil spring that presses the rack guide toward the rack bar.

  In such a rack and pinion type steering device, the rack bar bends due to a force acting away from each other with the rotation of the pinion shaft at the meshing portion of the rack teeth and the pinion of the rack bar. As a result of increased rattling in the direction of the arrangement of the strips, a hitting sound is generated between the teeth of the rack teeth and the pinion. The rack guide is pressed against the rack bar by the elastic pressing force of the coil spring, and the concave surface of the rack guide is brought into sliding contact with the rack bar to reduce the sliding friction resistance with the rack bar. The rattling of teeth in the arrangement direction of the teeth is suppressed, and the hitting sound at the meshing portion between the rack teeth and the pinion is reduced.

  As a rack guide, one using a sintered metal or one made of aluminum or an aluminum alloy has been proposed, but any rack guide needs to ensure a function of moving the rack guide within the gear case. In addition, a clearance (clearance) of about 20 μm is provided between the rack guide and the inner surface of the gear case. Even when such a clearance is provided, the twisting of teeth caused by the meshing of the pinion and the rack teeth If a radial load is applied to the rack guide by the action of the wheels on both ends of the rack bar, the rack guide may be strongly pressed against the inner surface of the gear case. In this state, the rack guide is coupled with the action of the pressing force by the coil spring. The gap between the guide and the gear case becomes so-called “togane”, which increases the frictional resistance, and consequently adheres. Cause Worn, problem prevent movement of the rack guide of the rack bar direction is generated.

  In order to solve the above-described problem, a rack guide with a buffer member such as an O-ring has been proposed, but when such a buffer member such as an O-ring is mounted, sliding between the buffer member and the inner surface of the gear case is not recommended. The load of the coil spring increases due to sliding resistance, and the coil spring is likely to sag (deteriorate). If the elastic spring force of the coil spring is insufficient due to this sag, the rack guide dances and the rack guide moves to the gear case. This also induces an abnormal sound (sound).

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rack capable of eliminating the generation of abnormal noise caused by the sag of the coil spring as a result of omitting the coil spring. It is an object of the present invention to provide a guide and a rack and pinion type steering device using the same.

  A rack guide for a rack and pinion type steering apparatus according to a first aspect of the present invention has a concave surface that slidably contacts the rack bar and a pressure receiving surface that receives a pressing force toward the rack bar; It comprises an elastically deformable member disposed on the pressure receiving surface side of the rack guide body, and a pressing member that applies a pressing force toward the rack bar to the elastically deformable member, wherein the elastically deformable member is: It is arranged between the rack guide body and the pressing member so as to be elastically deformed by the pressing force from the pressing member toward the rack bar and bulge in a direction orthogonal to the direction of the pressing force.

  According to the rack guide of the first aspect, the rack guide body and the pressing member are elastically deformed by the pressing force from the pressing member toward the rack bar and bulge in a direction orthogonal to the direction of the pressing force. Since the elastically deformable member is disposed between the elastically deformable member, the elastically deformable member performs the same function as a buffer member such as an O-ring and elastically deforms according to the magnitude of the reaction force against the pressing force. As a result of being able to change the bulging amount or hardness of the universal member and to generate an elastic pressing force toward the rack bar by an elastically deformable member instead of the coil spring, the inner surface of the gear case of the rack guide body In addition, it is possible to reliably avoid direct contact with the coil spring, and it is possible to omit the coil spring and to eliminate the generation of abnormal noise due to the coil spring sag.

  In a preferred example, like the rack guide of the second aspect of the present invention, the pressure receiving surface has an orthogonal pressure receiving surface orthogonal to the direction of the pressing force, and the elastically deformable member faces the orthogonal pressure receiving surface. And has an orthogonal pressing surface having a shape corresponding to the orthogonal pressure receiving surface, and is disposed between the orthogonal pressure receiving surface of the rack guide body and the pressing member. As in the rack guide of this aspect, the orthogonal pressure receiving surface and the orthogonal pressing surface are in contact with each other.

  In another preferred example, as in the rack guide according to the fourth aspect of the present invention, the pressure receiving surface includes a pair of inclined pressure receiving surfaces that are inclined with respect to the direction of the pressing force and gradually separated in the direction of the pressing force. A pair of orthogonal pressure receiving surfaces connected to the edges in the direction of the pressing force of the pair of inclined pressure receiving surfaces and orthogonal to the direction of the pressing force, and the elastically deformable member is provided on the pair of inclined pressure receiving surfaces. An inclined pressing surface having a shape corresponding to a pair of inclined pressure receiving surfaces and a pair of orthogonal pressing surfaces facing the pair of orthogonal pressure receiving surfaces and having a shape corresponding to the orthogonal pressure receiving surface are provided. The pressure receiving surface is arranged between the inclined pressure receiving surface and the orthogonal pressure receiving surface and the pressing member with respect to the direction of the pressing force. In this case, as in the rack guide according to the fifth aspect of the present invention, Each edge in the direction of As in the rack guide of the sixth aspect of the present invention, each of the inclined pressure receiving surface and the inclined pressing surface is a straight plane or a curved surface, as in the rack guide of the seventh aspect of the present invention. In addition, the inclined pressure receiving surface and the inclined pressing surface may be in contact with each other, and the orthogonal pressure receiving surface and the orthogonal pressing surface may be in contact with each other.

  In the rack guide according to any one of the fourth to seventh aspects, as in the rack guide according to the eighth aspect of the present invention, each of the pair of inclined pressure receiving surfaces is connected to each other, and Even though they are connected to each other, like the rack guide of the ninth aspect of the present invention, each of the pair of inclined pressure receiving surfaces is parallel to the moving direction of the rack bar, and the distance between them is in the direction of the pressing force. It has other edges in the direction opposite to the direction of the pressing force that is narrower than the distance between the pair of edges, and the pressure receiving surface is connected to each of the other edges and is in the direction of the pressing force. The elastically deformable member has another orthogonal pressure surface that faces the other orthogonal pressure receiving surface and has a shape corresponding to the other orthogonal pressure receiving surface. And other orthogonal pressure receiving surfaces and pressing members with respect to the direction of the pressing force It may also be provided between, in this case, as in the rack guide of the tenth aspect of the present invention, may be in contact with each other with other orthogonal pressure receiving surface and the other orthogonal pressing surface.

  According to the rack guides of the fourth to tenth aspects, since the rack guide body receives a pressing force toward the rack bar via the inclined pressure receiving surface, the rack guide body has some elastic deformability. As a result, the rack bar is supported from both sides through such a rack guide body, so that the rack bar is supported more slidably and stably.

  In the rack guide according to the eleventh aspect of the present invention, in the rack guide according to any one of the above aspects, the pressing member has an orthogonal pressing surface orthogonal to the direction of the pressing force, and is an elastically deformable member. Has an orthogonal pressure receiving surface facing the orthogonal pressing surface of the pressing member and having a shape corresponding to the orthogonal pressing surface of the pressing member, and is disposed between the rack guide body and the orthogonal pressing surface of the pressing member. In this case, like the rack guide according to the twelfth aspect of the present invention, the orthogonal pressure receiving surface of the elastically deformable member and the orthogonal pressing surface of the pressing member may be in contact with each other.

  In a preferred example of the present invention, the rack guide main body includes an orthogonal long groove that is disposed on the concave surface and extends perpendicular to the moving direction of the rack bar, like the rack guide of the thirteenth aspect. Further, like the rack guide of the fourteenth aspect, it is provided with a bottom long groove that is arranged at the bottom of the concave surface and extends in parallel with the moving direction of the rack bar, and further, the fifteenth aspect. Like the rack guide, an orthogonal long groove that is arranged on the concave surface and extends perpendicular to the moving direction of the rack bar, and a bottom long groove that is arranged on the bottom of the concave surface and extends parallel to the moving direction of the rack bar In this case, the bottom long groove is wider and deeper than the orthogonal long groove.

  Since the rack guide has at least one of the bottom long groove and the orthogonal long groove, the lubricating oil such as grease can be stored in the rack guide, and the lubricating oil can be supplied between the rack bar and the concave surface so that the rack bar is more In addition to being slidably supported with low frictional resistance, if the rack guide body has an inclined pressure-receiving surface, the concave groove can be easily deformed by the bottom long groove. The rack bar can be supported more stably and movably.

  Each of the elastically deformable member and the pressing member preferably has a through hole as in the rack guide of the sixteenth aspect of the present invention. In this case, the rack guide body has a concave surface and a pressure receiving surface. And a support portion that is integrally provided at one end of the main body portion and that penetrates the through holes of the elastically deformable member and the pressing member. Like the rack guide of the seventeenth aspect, the rack guide main body supports the slit that facilitates insertion of the support portion into the through hole and the bulging portion that prevents the support portion from coming out of the through hole of the pressing member. It is good to have at the other end of the part.

  According to the rack guide of the sixteenth aspect, the rack guide main body, the elastically deformable member and the pressing member can be integrated so that the gear case can be easily mounted in the rack guide, and the rack can be mounted on the elastically deformable member. The guide body and the pressing member can be firmly fixed.

  The rack guide main body or the pressing member may be made of metal or synthetic resin like the rack guide of the eighteenth aspect of the present invention, and as the metal material forming the rack guide main body, sintered metal, Aluminum or an aluminum alloy can be cited as a preferred example, and a polyacetal can be cited as a preferred example of the synthetic resin material forming the rack guide body, and the metal material forming the pressing member can be a sintered metal, aluminum or Polyacetal can be mentioned as an aluminum alloy and a synthetic resin material, respectively.

  The elastically deformable member may have various shapes of outer peripheral surfaces as long as it can abut against the inner surface of the gear case and bulge due to the elastic deformation to avoid a direct collision with the inner surface of the gear case of the rack guide body. Preferably, it has a cylindrical outer peripheral surface.

  The elastically deformable member is preferably made of a resin such as natural or synthetic rubber or polyurethane elastomer, like the rack guide of the nineteenth aspect of the present invention, but the present invention is not limited to these, Other natural or synthetic resins exhibiting elastic deformability such as urethane rubber may be used.

  In the rack guide of the present invention, another member, for example, a spacer member may be interposed between at least one of the rack guide main body and the elastically deformable member and between the elastically deformable member and the pressing member. Further, the elastically deformable member may be composed of a plurality of elastically deformable plates, for example, a laminate of rubber plates, and the inclined pressure receiving surface is a straight plane (flat surface), a semi-cylindrical shape or a spherical shape. It is not limited to a curved surface such as a polygonal surface.

  A rack and pinion type steering device according to a first aspect of the present invention includes a gear case, a pinion rotatably supported by the gear case, a rack bar formed with rack teeth meshing with the pinion, and a slide of the rack bar. The rack guide according to any one of the above-described aspects is supported, and the rack guide body and the pressing member are disposed in the gear case with a gap with respect to the gear case. The inner surface of the gear case comes into contact with the bulge caused by the pressing force toward the applied rack bar.

  According to the rack and pinion type steering device of such a first aspect, the rack guide body can be held according to the magnitude of the reaction force against the pressing force by the elastically deformable member that contacts the inner surface of the gear case. Since the elastic pressing force toward the rack bar can be generated by the elastically deformable member, direct contact of the rack guide main body with the inner surface of the gear case can be surely avoided, and the coil spring can be omitted. Occurrence of abnormal noise due to dripping can be eliminated.

  The rack and pinion type steering device of the present invention further includes a screw member that is screwed to the inner surface of the gear case and applies a pressing force toward the rack bar to the pressing member, like the rack and pinion type steering device of the second aspect. However, instead of having such a screw member, as in the rack and pinion type steering device of the third aspect of the present invention, the pressing member is screwed to the inner surface of the gear case on its peripheral surface. In this way, by screwing the pressing member to the inner surface of the gear case, the advancement / retraction position of the pressing member with respect to the gear case can be determined by the rotation of the pressing member, so that the pressing toward the rack bar can be performed without providing the screw member. The pressure can be applied to the elastically deformable member by the pressing member itself.

  According to the present invention, as a result of omitting the coil spring, it is possible to provide a rack guide and a rack and pinion steering device using the same that can eliminate the occurrence of abnormal noise caused by the sag of the coil spring. .

  Next, the present invention and the best mode for carrying it out will be described in more detail based on the preferred embodiments shown in the drawings. The present invention is not limited to these examples.

  1 to 6, the rack and pinion type steering device 1 of this example is supported by a gear case 3 made of aluminum or an aluminum alloy having a hollow portion 2 and a gear case 3 via rolling bearings 4 and 5 so as to be rotatable. The steering shaft 6 is disposed in the hollow portion 2 and is provided integrally with a shaft end portion (pinion shaft) of the steering shaft 6 and is rotatably supported by the gear case 3 via the steering shaft 6. A pinion 7, a rack bar 9 formed with rack teeth 8 that mesh with the pinion 7, and a rack that is arranged in the hollow portion 2 in the gear case 3 and supports the rack bar 9 slidably in the movement direction A The guide 10, the screw member 13 screwed to the inner surface 12 of the cylindrical part 11 of the gear case 3, and the cylindrical part 11 screwed to the screw member 13. It is provided with a lock nut 14 abuts.

  A rack bar 9 that passes through the gear case 3 in a direction perpendicular to the axis of the steering shaft 6 (moving direction A) and is movable in the perpendicular direction faces the surface on which the rack teeth 8 are formed. A semi-cylindrical outer peripheral surface 15 is provided on the back side.

  The rack guide 10 has a semi-cylindrical concave surface 21 that slidably contacts the semi-cylindrical outer peripheral surface 15 of the rack bar 9 and a pressure receiving surface 22 that receives a pressing force F toward the rack bar 9. A main body 23, an annular elastically deformable member 24 disposed on the pressure receiving surface 22 side of the rack guide main body 23, and an annular pressing member 25 that applies a pressing force F toward the rack bar 9 to the elastically deformable member 24. doing.

  The rack guide main body 23 made of metal or synthetic resin is provided with a main body portion 26 having a concave surface 21 and a pressure receiving surface 22, and is provided integrally with the main body portion 26 at one end, and an elastically deformable member 24 and a pressing member. A cylindrical support portion 29 penetrating through each of the 25 through holes 27 and 28, a bottom long groove 30 that is arranged at the bottom of the concave surface 21 and extends parallel to the moving direction A of the rack bar 9, and a concave portion 21. And an orthogonal long groove 31 extending orthogonally to the direction in which the bottom long groove 30 extends.

  The main body 26 has a cylindrical outer peripheral surface 32 in addition to the concave surface 21 and the pressure receiving surface 22, and the pressure receiving surface 22 includes an annular orthogonal pressure receiving surface 33 orthogonal to the direction of the pressing force F, A cross-shaped slit 34 that facilitates elastic deformation of the other end of the rack guide main body 23 or the support portion 29 to facilitate insertion of the support portion 29 into the through holes 27 and 28, and an annular stepped portion of the pressing member 25 , And a bulging portion 36 that engages 35 and prevents the support portion 29 from coming out of the through hole 28 of the pressing member 25 at the other end of the support portion 29. Are also wide and deep grooves.

  An annular elastically deformable member 24 made of a resin such as natural or synthetic rubber or polyurethane elastomer faces the orthogonal pressure receiving surface 33 and has an annular orthogonal pressing surface 41 having a shape corresponding to the orthogonal pressure receiving surface 33, and a pressing force. An annular orthogonal pressure-receiving surface 43 facing the orthogonal pressing surface 42 of the member 25 and having a shape corresponding to the orthogonal pressing surface 42 of the pressing member 25, a cylindrical outer peripheral surface 44, and the support portion 29 penetrate therethrough. A rack from the pressing member 25 has a through hole 27 and a cylindrical inner peripheral surface 46 that slidably contacts the cylindrical outer peripheral surface 45 of the support portion 29 and defines the through hole 27. In order to be elastically deformed by the pressing force F toward the bar 9, the orthogonal pressing surface 41 contacts the orthogonal pressure receiving surface 33 and the orthogonal pressure receiving surface 43 contacts the orthogonal pressing surface 42, and the rack in the direction of the pressing force F It is arranged between the orthogonal pressing surface 42 of the orthogonal pressure receiving surface 33 and the pressing member 25 of the id body 23.

  An annular pressing member 25 made of metal or synthetic resin includes an annular orthogonal pressing surface 42 orthogonal to the direction of the pressing force F, a through hole 28 through which the support portion 29 passes, and a through hole 28. A through hole 47 that is connected and has a diameter larger than that of the through hole 28, an annular orthogonal pressure receiving surface 48 that is orthogonal to the direction of the pressing force F, a cylindrical outer peripheral surface 49, and an outer peripheral surface of the support portion 29. A cylindrical inner peripheral surface 50 that is slidably in contact with 45 and that defines the through hole 28, a cylindrical inner peripheral surface 51 that defines the through hole 47, an inner peripheral surface 50, and an inner peripheral surface 51 And an annular step 35 disposed between the two.

  The main body portion 26 of the rack guide main body 23 is disposed in the gear case 3 with a gap with respect to the inner surface 12 of the cylindrical portion 11 of the gear case 3 on the outer peripheral surface 32, and the pressing member 25 also has a gear case on the outer peripheral surface 44. The rack guide body 23 and the pressing member 25 are each screw member 13 screwed into the cylindrical portion 11 of the gear case 3. In contrast to the elastically deformable member 24, it is movable in the direction of the pressing force F, and is movable by a gap in the direction orthogonal to the direction of the pressing force F. The rack guide main body 23 and the pressing member 25 are elastically deformed by the pressing force F toward 9 and bulge in a direction orthogonal to the direction of the pressing force F. The elastically deformable member 24 disposed therebetween bulges toward the cylindrical inner surface 12 of the gear case 3 by the applied pressing force F toward the rack bar 9 and pushes toward the applied rack bar 9. The outer peripheral surface 44 is in contact with the inner surface 12 of the gear case 3 due to the bulge caused by the pressure F.

  The screw member 13 has an annular orthogonal pressing surface 55 that faces and contacts the orthogonal pressure receiving surface 48 and has a shape corresponding to the orthogonal pressure receiving surface 48, and the pressing force toward the rack bar 9 on the pressing member 25. F is given.

  In the rack and pinion type steering device 1 described above, the screw member 13 is screwed into the cylindrical portion 11 to apply a constant pressing force F to the pressing member 25, and then the screw member 13 is fixed to the cylindrical portion 11 by the lock nut 14. Then, the pressing force F applied to the pressing member 25 causes the elastically deformable member 24 to elastically deform and is transmitted to the rack guide main body 23. As a result, the rack guide main body 23 is caused by the elastic deformation of the elastic deformable member 24. The rack bar 9 is slidably elastically supported by the concave surface 21 by the elastic force in the direction of the pressing force F, and the meshing of the rack teeth 8 with the pinions 7 is ensured in the rotation of the steering shaft 6. And the pinion 7 at the meshing portion is reduced to guide the movement of the rack bar 9 in the direction perpendicular to the axis of the steering shaft 6 due to the meshing, and the elastic deformation itself. The member 24 bulges toward the cylindrical inner surface 12 of the gear case 3 by elastic deformation due to the applied pressing force F toward the rack bar 9 and comes into contact with the inner surface 12 of the gear case 3 at its outer peripheral surface 44. As a result of being able to change the bulge amount or hardness according to the magnitude of the reaction force against the pressure F, direct contact of the rack guide body 23 with the inner surface 12 of the gear case 3 can be avoided reliably, and the rack Even if a dance occurs in the guide main body 23, it is possible to avoid a collision between the rack guide main body 23 and the inner surface 12 of the gear case 3, and to prevent an abnormal noise due to the collision. Moreover, in the rack guide 10, the elastically deformable member 24 is sandwiched between the orthogonal pressure receiving surface 33 of the rack guide main body 23 and the orthogonal pressing surface 42 of the pressing member 25, so that the elastic deformable member 24 is deformed by creep deformation. Therefore, a stable elastic pressing force F can be applied to the rack bar 9.

  Thus, according to the rack and pinion type steering device 1, the elastically deformable member 24 can generate the elastic pressing force F toward the rack bar 9, and thus the inner surface 12 of the gear case 3 of the rack guide body 23. In addition, the coil spring can be omitted and the generation of abnormal noise due to the sag of the coil spring can be eliminated.

  The above is an example of the rack guide 10 having the main body portion 26 having the orthogonal pressure receiving surface 33 as the pressure receiving surface 22, but instead of this, as shown in FIGS. The rack guide 10 having the main body portion 26 having the inclined pressure receiving surfaces 61 and 62 may be used. That is, the pressure receiving surface 22 of the main body 26 shown in FIGS. 7 to 9 is parallel to the moving direction A of the rack bar 9 and a pair of edges 63 and 64 in the direction of the pressing force F and the moving direction A of the rack bar 9. And a pair of end edges 65 and 66 in a direction opposite to the direction of the pressing force F which is narrower than the distance between the pair of end edges 63 and 64 and is opposite to the direction of the pressing force F. A pair of inclined pressure receiving surfaces 61 and 62 that are inclined and gradually separated in the direction of the pressing force F, and a pair of orthogonal pressure receiving surfaces 67 and 68 that are connected to the edges 63 and 64 and are orthogonal to the direction of the pressing force F. And orthogonal pressure receiving surfaces 69 and 70 connected to the end edges 65 and 66 and orthogonal to the direction of the pressing force F.

  In the case of the rack guide 10 having the main body portion 26 shown in FIGS. 7 to 9, the annular elastically deformable member 24 faces a pair of inclined pressure receiving surfaces 61 and 62 each having a straight plane as shown in FIG. And a pair of inclined pressing surfaces 81 and 82 having a shape corresponding to the pair of inclined pressure receiving surfaces 61 and 62, and a shape corresponding to the orthogonal pressure receiving surfaces 67 and 68 and the orthogonal pressure receiving surfaces 67 and 68. A pair of orthogonal pressing surfaces 83 and 84, and orthogonal pressing surfaces 85 and 86 which face the orthogonal pressure receiving surfaces 69 and 70 and have shapes corresponding to the orthogonal pressure receiving surfaces 69 and 70; With respect to the direction, the pair of orthogonal pressure receiving surfaces 67 and 68, the pair of inclined pressure receiving surfaces 61 and 62, the orthogonal pressure receiving surfaces 69 and 70 and the orthogonal pressing surface 42 of the pressing member 25 are arranged. Thus, each of the pair of inclined pressure receiving surfaces 61 and 62 and each of the pair of inclined pressing surfaces 81 and 82 formed of a plane are in contact with each other, and each of the pair of orthogonal pressure receiving surfaces 67 and 68 and the pair of orthogonal pressing surfaces. The surfaces 83 and 84 are in contact with each other, the orthogonal pressure receiving surfaces 69 and 70 and the orthogonal pressing surfaces 85 and 86 are in contact with each other, and the orthogonal pressure receiving surface 43 and the orthogonal pressing surface 42 are in contact with each other. Yes.

  Also in the rack and pinion type steering apparatus 1 having the rack guide 10 shown in FIGS. 7 to 10, the pressing force F applied to the pressing member 25 is transmitted to the rack guide main body 23 by elastically deforming the elastic deformable member 24. As a result, the rack guide body 23 elastically supports the rack bar 9 slidably on the concave surface 21 by the elastic force in the direction of the pressing force F resulting from the elastic deformation of the elastically deformable member 24, and A direction perpendicular to the axial center of the steering shaft 6 due to the meshing by securing the meshing of the rack teeth 8 with the pinion 7 in rotation and reducing the hitting sound at the meshing part of the rack teeth 8 and the pinion 7 The elastic deformable member 24 guides the movement of the rack bar 9 to the cylindrical inner surface 12 of the gear case 3 by elastic deformation due to the pressing force F directed to the applied rack bar 9. As a result, the rack guide body can bulge and contact the inner surface 12 of the gear case 3 at its outer peripheral surface 44, and the bulge amount or hardness can be changed according to the magnitude of the reaction force against the pressing force F. 23, the direct contact with the inner surface 12 of the gear case 3 can be reliably avoided, and even if the rack guide main body 23 is danced, the collision between the rack guide main body 23 and the inner surface 12 of the gear case 3 can be avoided. It is possible to prevent the generation of abnormal noise. Moreover, in the rack guide 10 shown in FIGS. 7 to 10, the elastically deformable member 24 is replaced with a pair of orthogonal pressure receiving surfaces 67 and 68, a pair of inclined pressure receiving surfaces 61 and 62, and a pair of orthogonal pressure receiving surfaces 69. And 70 and the orthogonal pressing surface 42 of the pressing member 25, the amount of sag due to creep deformation of the elastically deformable member 24 can be reduced, and a stable elastic pressing force F can be applied to the rack bar 9. In addition, since the rack guide body 23 receives the pressing force F toward the rack bar 9 via the inclined pressure receiving surfaces 61 and 62, the rack guide body 23 has a certain degree of elastic deformation. As a result, the rack bar 9 is supported in a more stable and slidable manner.

  In the rack guide 10 shown in FIGS. 7 to 10, each of the pair of inclined pressure receiving surfaces 61 and 62 and the pair of inclined pressing surfaces 81 and 82 is constituted by a straight plane, but instead of this, FIGS. As shown in FIG. 11, the pair of inclined pressure receiving surfaces 61 and 62 and the pair of inclined pressing surfaces 81 and 82 may be formed of a semi-cylindrical curved surface, and the pressure receiving surface 22 of the main body portion 26 shown in FIGS. The rack bar 9 has a pair of edges 63 and 64 parallel to the moving direction A of the rack bar 9 in the direction of the pressing force F, is inclined with respect to the direction of the pressing force F, and is gradually separated in the direction of the pressing force F. Each includes a pair of inclined pressure receiving surfaces 61 and 62 each having a semi-cylindrical curved surface, and a pair of orthogonal pressure receiving surfaces 67 and 68 connected to the end edges 63 and 64 and orthogonal to the direction of the pressing force F. A pair of Each of the oblique pressure receiving surface 61 and 62, are connected to one another by a pair of edges 65 and 66 in the direction opposite to the direction of the pressing force F.

  In the case of the rack guide 10 having the main body 26 shown in FIGS. 11 to 13, the annular elastically deformable member 24 is a semi-cylinder as shown in FIG. 14 in addition to the outer peripheral surface 44 and the orthogonal pressure receiving surface 43. A pair of inclined pressure receiving surfaces 61 and 62 having a shape corresponding to the pair of inclined pressure receiving surfaces 61 and 62 and each having a shape corresponding to the pair of inclined pressure receiving surfaces 61 and 62, And a pair of orthogonal pressing surfaces 83 and 84 having a shape corresponding to the orthogonal pressure receiving surfaces 67 and 68 and facing the orthogonal pressure receiving surfaces 67 and 68, with respect to the direction of the pressing force F. The pair of inclined pressure receiving surfaces 61 and 62 and the pair of orthogonal pressure receiving surfaces 67 and 68 are arranged between the orthogonal pressing surface 42 of the pressing member 25, and the pair of inclined pressing surfaces 81 and 82 are connected to each other. The pair of inclined pressure receiving surfaces 61 and 62 and the pair of inclined pressing surfaces 81 and 82 are in contact with each other, and the pair of orthogonal pressure receiving surfaces 67 and 68 and the pair of orthogonal pressing surfaces 83 and 84 are in contact with each other. Are in contact with each other, and the orthogonal pressure receiving surface 43 and the orthogonal pressing surface 42 are in contact with each other.

  In the rack guide 10 shown in FIGS. 11 to 14, the rack guide main body 23 includes tapered surfaces 91 and 92 provided at both ends in the moving direction A of the concave surface 21 in addition to the semicylindrical concave surface 21. The rack guide body 23 includes an orthogonal long groove 31 that is disposed on the concave surface 21 and extends orthogonal to the moving direction A of the rack bar 9.

  Even with the rack and pinion type steering device 1 provided with the rack guide 10 shown in FIGS. 11 to 14, the same effects as those of the above-described rack and pinion type steering device 1 can be obtained.

  In the above example, the screw member 13 is screwed into the cylindrical portion 11 so as to apply a constant pressing force F to the pressing member 25. However, the screw member 13 is omitted and the pressing member 25 is connected to the gear case on its outer peripheral surface 49. 3 may be screwed onto the inner surface 12 and a certain pressing force F may be applied to the elastically deformable member 24 by screwing the pressing member 25 into the cylindrical portion 11.

It is sectional drawing of a preferable example of embodiment of this invention. It is sectional drawing of the rack guide main body shown in FIG. It is a top view of the rack guide main body shown in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. 3. It is a perspective view top view of the elastically deformable member shown in FIG. It is sectional drawing of the press member shown in FIG. It is sectional drawing of another preferable example of embodiment of this invention. It is sectional drawing of the rack guide main body shown in FIG. It is a side view of the rack guide main body shown in FIG. It is a perspective view of the elastically deformable member shown in FIG. It is sectional drawing of another preferable example of embodiment of this invention. It is a top view of the rack guide main body shown in FIG. FIG. 13 is a cross-sectional view taken along line XIII-XIII shown in FIG. 12. It is a perspective view of the elastically deformable member shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rack and pinion type steering device 2 Hollow part 3 Gear case 7 Pinion 8 Rack tooth 9 Rack bar 21 Concave surface 22 Pressure receiving surface 23 Rack guide main body 24 Elastically deformable member 25 Press member

Claims (22)

  A rack guide body having a concave surface slidably contacting the rack bar and having a pressure receiving surface for receiving a pressing force toward the rack bar; an elastically deformable member disposed on the pressure receiving surface side of the rack guide body; And a pressing member that applies a pressing force toward the rack bar to the elastically deformable member. The elastic deformable member is elastically deformed by the pressing force from the pressing member toward the rack bar, and is in the direction of the pressing force. A rack guide for a rack and pinion type steering device, which is arranged between a rack guide main body and a pressing member so as to bulge in a direction orthogonal to each other.   The pressure receiving surface has an orthogonal pressure receiving surface that is orthogonal to the direction of the pressing force, and the elastically deformable member has an orthogonal pressing surface that faces the orthogonal pressure receiving surface and has a shape corresponding to the orthogonal pressure receiving surface. The rack guide according to claim 1, wherein the rack guide is disposed between the orthogonal pressure receiving surface and the pressing member with respect to the direction of the pressing force.   The rack guide according to claim 2, wherein the orthogonal pressure receiving surface and the orthogonal pressing surface are in contact with each other.   The pressure receiving surface is connected to a pair of inclined pressure receiving surfaces that are inclined with respect to the direction of the pressing force and are gradually separated in the direction of the pressing force, and edges of the pair of inclined pressure receiving surfaces in the direction of the pressing force and the pressing force. A pair of orthogonal pressure receiving surfaces orthogonal to the direction of the elastic deformation member, and the elastically deformable member faces the pair of inclined pressure receiving surfaces and has an inclined pressing surface having a shape corresponding to the pair of inclined pressure receiving surfaces; And a pair of orthogonal pressure surfaces facing the pair of orthogonal pressure receiving surfaces and having a shape corresponding to the orthogonal pressure receiving surface, and between the inclined pressure receiving surface and the orthogonal pressure receiving surface and the pressing member with respect to the direction of the pressing force. The rack guide according to claim 1, which is disposed on the rack.   The rack guide according to claim 4, wherein each edge in the direction of the pressing force of the pair of inclined pressure receiving surfaces is parallel to the moving direction of the rack bar.   The rack guide according to claim 4 or 5, wherein each of the inclined pressure receiving surface and the inclined pressing surface is a straight plane or a curved surface.   The rack guide according to any one of claims 4 to 6, wherein the inclined pressure receiving surface and the inclined pressing surface are in contact with each other, and the orthogonal pressure receiving surface and the orthogonal pressing surface are in contact with each other.   The rack guide according to any one of claims 4 to 7, wherein each of the pair of inclined pressure receiving surfaces is connected to each other, and each of the pair of inclined pressing surfaces is connected to each other.   Each of the pair of inclined pressure receiving surfaces is parallel to the moving direction of the rack bar, and the other end in the direction opposite to the direction of the pressing force is smaller than the distance between the pair of end edges in the direction of the pressing force. The pressure-receiving surface is connected to each of the other end edges and includes another orthogonal pressure-receiving surface orthogonal to the direction of the pressing force, and the elastically deformable member is It has another orthogonal pressing surface facing the pressure receiving surface and having a shape corresponding to the other orthogonal pressure receiving surface, and is arranged between the other orthogonal pressure receiving surface and the pressing member with respect to the direction of the pressing force. The rack guide according to any one of claims 4 to 7.   The rack guide according to claim 9, wherein the other orthogonal pressure receiving surface and the other orthogonal pressing surface are in contact with each other.   The pressing member has an orthogonal pressing surface orthogonal to the direction of the pressing force, and the elastically deformable member faces the orthogonal pressing surface of the pressing member and has a shape corresponding to the orthogonal pressing surface of the pressing member. The rack guide according to any one of claims 1 to 10, further comprising an orthogonal pressure receiving surface and disposed between the rack guide body and the orthogonal pressing surface of the pressing member with respect to the direction of the pressing force.   The rack guide according to claim 11, wherein the orthogonal pressure receiving surface of the elastically deformable member and the orthogonal pressing surface of the pressing member are in contact with each other.   The rack guide according to any one of claims 1 to 12, wherein the rack guide body includes an orthogonal long groove that is disposed on the concave surface and extends orthogonal to the moving direction of the rack bar.   The rack guide according to any one of claims 1 to 13, wherein the rack guide main body includes a bottom long groove that is disposed on the bottom of the concave surface and extends in parallel with the moving direction of the rack bar.   The rack guide main body has an orthogonal long groove disposed on the concave surface and extending perpendicular to the moving direction of the rack bar, and a bottom long groove disposed on the bottom portion of the concave surface and extending in parallel with the moving direction of the rack bar. The rack guide according to any one of claims 1 to 12, further comprising a deep groove that is wider and deeper than the orthogonal long groove.   Each of the elastically deformable member and the pressing member has a through hole, and the rack guide main body is integrally provided at one end with the main body having a concave surface and a pressure receiving surface and elastically deformed. The rack guide according to any one of claims 1 to 15, further comprising a support portion that passes through each through hole of the universal member and the pressing member.   The rack guide body has a slit for facilitating insertion of the support portion into the through hole and a bulging portion for preventing the support portion from coming out of the through hole of the pressing member at the other end of the support portion. The rack guide according to 16.   The rack guide according to any one of claims 1 to 17, wherein the rack guide body or the pressing member is made of metal or synthetic resin.   The rack guide according to any one of claims 1 to 18, wherein the elastically deformable member is made of a resin such as natural or synthetic rubber or polyurethane elastomer.   20. A gear case, a pinion rotatably supported by the gear case, a rack bar formed with rack teeth meshing with the pinion, and the rack bar slidably supported. The rack guide main body and the pressing member are arranged in the gear case with a gap with respect to the inner surface of the gear case, and the elastically deformable member has a pressing force toward the applied rack bar. Rack-and-pinion type steering device that comes into contact with the inner surface of the gear case by bulging due to.   21. The rack and pinion type steering device according to claim 20, further comprising a screw member that is screwed onto an inner surface of the gear case and applies a pressing force toward the rack bar to the pressing member.   21. The rack and pinion type steering device according to claim 20, wherein the pressing member is screwed to the inner surface of the gear case at a circumferential surface thereof.

Images