JP5025185B2 - Rack guide and rack and pinion type steering apparatus provided with the rack guide - Google Patents

Description

  The present invention relates to a rack guide used in a steering apparatus or the like that performs steering by reciprocating a rack bar via a pinion by a steering operation of a vehicle such as an automobile, and a rack and pinion type steering apparatus including the rack guide.

  As shown in FIG. 12, a conventional rack and pinion type steering device 61 generally includes a pinion 65 rotatably disposed in a housing 62 via bearings 63 and 64 so as to be rotated by steering, and this pinion. A rack bar 66 having rack teeth 66a meshing with the pinion 65 so as to move in a direction perpendicular to the paper surface by the rotation of 65, and a lateral direction (rack) in the housing 62 so as to guide the movement of the rack bar 66 A rack guide 68 movably disposed in a cylindrical holding hole 62a extending in a direction orthogonal to the moving direction of the bar 66, a lid member 69 for closing the holding hole 62a of the housing 62, and a rack guide 68. The coil spring 7 is arranged between the coil springs 7 and elastically presses the rack teeth 66 a of the rack bar 66 against the pinion 65 via the rack guide 68. Provided with a door.

  In this rack and pinion type steering device 61, the rack bar 66 is engaged with the rack teeth 66a of the rack bar 66 and the pinion 65, and the rack bar 66 bends due to the forces acting away from each other as the pinion shaft rotates. As a result, the backlash in the arrangement direction of the teeth of the rack teeth 66a is increased, so that a hitting sound is generated between the teeth of the rack teeth 66a and the pinion 65, and therefore a concave surface having a small frictional resistance on the opposite side to the pinion shaft, In many cases, a rack guide 68 having a semi-cylindrical concave surface is provided. The concave surface of the rack guide 68 is pressed against the rack bar 66 by the elastic pressing force of the coil spring 70, and the concave surface of the rack guide 68 is brought into sliding contact with the rack bar 66. Thus, the sliding frictional resistance with the rack bar 66 is reduced, the rattling of the rack teeth 66a in the arrangement direction of the rack teeth 66a is suppressed, and the rack teeth 66a and the pinions 65 are engaged with each other. Configured to reduce the impact sound in parts.

Microfilm of actual application No.56-115067 JP-A-6-239245

  In the rack and pinion type steering device 61, as the rack guide 68, a rack guide 68 formed of iron-based sintered metal, aluminum alloy or synthetic resin has been proposed. The rack guide 68 made of iron-based sintered metal or aluminum alloy has sufficient mechanical strength against the impact load from the rack bar 66, but has a problem that the efficiency of the steering system is reduced because of high sliding friction resistance. There is. On the other hand, the rack guide 68 made of synthetic resin can reduce sliding frictional resistance, but is inferior in mechanical strength against high load or impact load, causes creep deformation, and the support ability of the rack bar 66 is reduced. There is a problem that it is difficult to support the bar 66 smoothly.

  In any rack guide 68, the rack guide 68 is allowed to move toward the pinion 65 between the outer peripheral surface 67 of the rack guide 68 and the inner peripheral surface 62b of the housing 62 that defines the holding hole 62a. When the annular gap Δ is large, the movement of the rack guide 68 along the radial direction of the holding hole 62a increases, and the outer peripheral surface 67 of the rack guide 68 and the inner peripheral surface 62b of the housing 62 are increased. And the collision noise between the rack teeth 66a and the teeth of the pinion 65 are increased.

In order to solve the above-described problem, an O-ring made of a rubber elastic body is interposed between the rack guide 68 and the housing 62, and the O-ring is connected to the outer peripheral surface 67 of the rack guide 68 and the inner peripheral surface 62b of the housing 62. Between the outer peripheral surface 67 of the rack guide 68 and the inner peripheral surface 62b of the housing 62 in the axial direction. There has been proposed (Patent Document 2) that restricts the movement of the rack guide 68 along the radial direction by sandwiching a small elastic member.

  However, when such an O-ring or a long elastic member is sandwiched between the outer peripheral surface 67 of the rack guide 68 and the inner peripheral surface 62 b of the housing 62, the O-ring or the long elastic member and the inner periphery of the housing 62 are arranged. Since the sliding frictional resistance with the surface 62b is large, the load of the coil spring 70 is increased due to the sliding frictional resistance, and the coil spring 70 is liable to be drooped (deteriorated), and the elastic pressing force of the coil spring 70 is insufficient. The rack guide 68 dances and the rack guide 68 collides with the housing 62, which also induces a hitting sound.

  Therefore, the present invention has been made in view of the above points, has high pressure resistance, can smoothly move in the direction of the rack bar in the housing, and avoids the occurrence of collision noise with the housing. Another object of the present invention is to provide a rack guide that can be used and a rack and pinion type steering device using the same.

In order to achieve the above object, the present invention provides a rack guide having a concave surface that slides and guides a rack bar, and a synthetic resin rack support that has a pressure receiving surface that receives a pressing force toward the rack bar. An elastic member disposed on the pressure receiving surface side of the rack support; and a pressing member that applies a pressing force toward the rack bar to the elastic member. The elastic member includes an annular block portion and the annular ring A plurality of projecting tongue pieces projecting radially on the upper end side of the outer peripheral surface of the block portion; and the pressing member includes an annular recess on an end surface facing the rack support, and the annular recess A plurality of notched recesses formed along the circumferential direction in the annular standing wall portion on the outer peripheral surface side, and the elastic member fits the annular block portion into the annular recess of the pressing member. Each of the plurality of protruding tongue pieces is And wherein fitted into each of the cutout recess of the annular vertical wall portion of the member is fitted to the pressing member, wherein the rack support, the pressure receiving surface, a end surface of the annular block portion of the elastic member The pressing member is disposed in contact with an end surface protruding from the opening of the annular recess.

  And according to this invention, by using the rack support body which consists of synthetic resins, the sliding frictional resistance between rack bars can be reduced, and the elastic member has an annular block portion at the end face of the pressing member. Since the end surface protruding from the opening of the annular recess is in contact with the pressure receiving surface of the rack support, the annular block portion is By closely filling the annular recess and exhibiting a behavior like a rigid body, the pressure resistance of the rack support in the axial direction of the rack support is increased, and as a result, the rack bar is supported by the rack support. Since the capability is enhanced, it is possible to avoid a decrease in support capability due to creep deformation, and the rack bar can be smoothly supported by sliding.

  In the rack guide, the pressure receiving surface may be configured to have an orthogonal pressure receiving surface that is orthogonal to the direction of the pressing force toward the rack bar.

  In the rack guide, each of the protruding tongue piece portions of the elastic member may have a circular arc surface, and may protrude from the outer peripheral surface of the pressing member. The front ends of the protruding tongue pieces of the elastic member are positioned in an annular gap between the outer peripheral surface of the rack guide and the inner peripheral surface of the housing, so that the outer periphery of the rack guide is based on the radial movement of the rack guide. Generation of a collision sound between the surface and the inner peripheral surface of the housing can be avoided. Further, since the protruding tongue piece portion of the elastic member is divided in the circumferential direction, smooth movement of the rack guide in the rack bar direction is not hindered.

  Further, in the rack guide, the pressing member has a through hole, and the rack support body is provided integrally with the pressure receiving surface and includes a projecting support portion that penetrates the through hole of the pressing member. it can. By inserting the protruding support portion of the rack support body into the through hole of the pressing member, the rack support body, the elastic member, and the pressing member can be easily integrated.

  Further, in the rack guide, the protruding support portion of the rack support body includes a cylindrical portion having a diameter smaller than the diameter of the through hole of the pressing member, and a slit groove formed on a free end side of the cylindrical portion. And a bulging portion that prevents the protruding support portion from coming out of the through hole after the protruding support portion is inserted into the through hole. By inserting the protruding support portion into the through hole using the slit groove, the protruding support portion can be easily inserted into the through hole of the rack support body, and the protruding support portion is penetrated by the bulging portion. Since the escape from the hole is prevented, the rack support and the pressing member can be reliably fixed to the elastic member.

  Further, in the rack guide, the elastic member integrally has a convex portion opposed to each other in a radial direction on one end surface of the annular block portion, and the pressure receiving surface of the rack support member sandwiches the concave surface. The elastic member may have a concave portion opposed to each other in the radial direction, and the elastic member may be arranged by fitting the convex portion into the concave portion of the pressure receiving surface of the rack support.

  According to the present invention, by fitting a radially opposing convex portion integrally formed on one end surface of the annular block portion with a concave portion formed on the pressure receiving surface of the rack support, The pressure resistance against the axial load of the rack support is further increased.

  Further, the present invention is a rack and pinion type steering device, a housing having a cylindrical holding hole therein, a pinion that is rotatably arranged in the housing and rotated by steering, and the pinion A rack bar having meshing rack teeth, a rack guide according to any one of claims 1 to 6, wherein the rack guide is movably disposed in a holding hole of the housing and movably guides and supports the rack bar. Elastic means for elastically pressing the rack teeth of the rack bar against the pinion via the rack guide, wherein the rack support and the pressing member are provided in the holding holes of the housing. The elastic member is arranged in the holding hole with an annular gap with respect to the inner surface, and the elastic member is attached to the rack bar by a pressing force directed toward the rack bar. It is compressed in the recess, and the annular recess is tightly filled, and the rebound elastic force is accumulated by the pressure receiving surface of the rack support coming into contact with the end surface of the annular recess of the pressing member, and is accumulated in the elastic member. The pressure resistance of the rack support is increased by the rebound resilience, and the support capacity of the rack bar is increased.

  According to the rack and pinion type steering device of the present invention, since the pressure resistance of the rack support is increased with respect to the axial direction of the rack support, the rack bar is supported even when a large load is input from the road surface. In addition, direct contact of the rack support body with the inner peripheral surface of the housing can be reliably avoided, and the movement of the rack guide toward the rack bar can be performed smoothly.

  In the rack and pinion type steering device, the elastic member can contact the inner surface of the holding hole of the housing with an allowance with an arc surface of a protruding tongue piece protruding from the outer peripheral surface of the pressing member. Since the protruding tongue piece portion of the elastic member is divided in the circumferential direction, even if the protruding tongue piece portion is brought into contact with the inner surface of the housing with a tightening margin, movement of the rack guide in the rack bar direction is prevented. Therefore, the movement can be performed smoothly.

  As described above, according to the present invention, a rack that has high pressure resistance, can smoothly move in the direction of the rack bar in the housing, and can avoid occurrence of collision noise with the housing. A guide and a rack and pinion type steering apparatus using the same can be provided.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a rack and pinion type steering device (hereinafter referred to as “steering device”) according to the present invention. The steering device 1 includes a housing 2 having a cylindrical holding hole 2a therein, Through a bearing 3 and 4 provided in the housing 2, a pinion 5 that rotates in the R direction around the axis O by steering, and a direction orthogonal to the plane of FIG. 1 due to the rotation of the pinion 5 in the R direction (FIG. 4). The rack bar 6 having rack teeth 6a meshing with the pinion 5 so as to move in the (A) direction of (a), and the holding hole 2a in the housing 2 to guide the movement of the rack bar 6 in the A direction, A rack guide 8 that is movably arranged in a C direction perpendicular to each of the A direction and the axial direction (B direction) of the pinion 5, and that guides and supports the rack bar 6 movably in the A direction; As an elastic means that is arranged between the lid member 9 that closes the holding hole 2 a of the rack 2 and the rack guide 8 and elastically presses the rack teeth 6 a of the rack bar 6 against the pinion 5 via the rack guide 8. Coil spring 10 or the like.

  The housing 2 includes a main body 2c having a cylindrical portion 2b and a holding hole 2a formed in the cylindrical portion 2b. As shown in FIG. 2, a lid member 9 is screwed on the inner peripheral surface 2d of the cylindrical portion 2b. The one end surface of the holding hole 2a is closed. The lid member 9 is fixed to the cylindrical portion 2b by the lock nut 12 so that the screwed state to the cylindrical portion 2b is not loosened.

  In FIG. 1, the rack bar 6 extends through the housing 2 in the A direction, and has an arc convex surface 6b on the surface opposite to the surface on which the rack teeth 6a are formed.

  As shown in FIG. 3, the rack guide 8 has an arc concave surface 14 b for slidingly guiding the arc convex surface 6 b of the rack bar 6 (see FIG. 2) on one end surface 14 a, and a pressing force F ( 1), a synthetic resin rack support 14 having a pressure receiving surface 14c, an annular elastic member 15 arranged on the pressure receiving surface 14c side of the rack support 14, and the elastic member 15 toward the rack bar 6. And a pressing member 16 that applies a pressing force F (see FIG. 1).

  The rack support 14 is made of a synthetic resin having self-lubricating properties such as polyacetal resin and polyamide resin. As shown in FIGS. 4 and 5, the main body 14d having an arcuate concave surface 14b and a pressure receiving surface 14c, and the pressure receiving pressure of the main body 14d. A protrusion support portion 14e formed integrally with the surface 14c and a long groove 14f formed at the bottom of the arc concave surface 14b and extending in a direction orthogonal to the movement method (A direction) of the rack bar 6 are provided. .

  The main body 14d has a cylindrical outer peripheral surface 14g in addition to the circular arc concave surface 14b and the pressure receiving surface 14c. The pressure receiving surface 14c is formed from an annular orthogonal pressure receiving surface 14h orthogonal to the direction of the pressing force F shown in FIG. Become.

  The projecting support portion 14e includes a columnar portion 14i and a bulging portion 14j at the end of the columnar portion 14i. The bulging portion 14j includes an upper flat surface portion 14k having an enlarged diameter connected to the outer surface of the columnar portion 14i, A lower flat surface portion 14m spaced from the flat surface portion 14k by a predetermined distance, a truncated conical surface 14n on the outer surface between the upper and lower flat surface portions 14k, 14m, and a cut formed from the end surface of the lower flat surface portion 14m toward the upper flat surface portion 14k. The groove 14p includes a through-hole 14r that opens from the bottom surface 14q of the slit groove 14p to the long groove 14f formed in the arc concave surface 14b.

  Since the bulging portion 14j of the projecting support portion 14e can be radially reduced by a slit groove 14p formed in the bulging portion 14j, the bulging portion 14j can be easily elastically deformed, and will be described later. The member 16 (see FIG. 7) can be easily inserted into the through-hole 16i, and the upper flat portion 14k is engaged with the periphery of the opening of the through-hole 16i that opens in the bottom surface of the cylindrical recess 16c of the pressing member 16. In combination, the protruding support portion 14e is prevented from coming off from the through hole 16i of the pressing member 16.

  The elastic member 15 shown in FIG. 6 is made of natural rubber or synthetic rubber, or synthetic resin elastomer such as polyester elastomer or polyurethane elastomer, and has an annular block portion 15a having a rectangular shape in a longitudinal section, and an annular block portion 15a. A plurality of (four in this example) protruding tongue pieces 15e protruding in the radial direction on the upper end side of the outer peripheral surface 15d via one end face 15b and a step portion 15c, the tip of the protruding tongue piece 15e Is formed on the circular arc surface 15f.

  One end surface 15b of the annular block portion 15a forms an annular orthogonal pressure receiving surface 15g facing the orthogonal pressure receiving surface 14h of the rack support 14 (see FIG. 4).

  The pressing member 16 shown in FIG. 7 is made of reinforced synthetic resin such as glass fiber or carbon fiber, and has a cylindrical outer peripheral surface 16a, a cylindrical recess 16c on one end surface 16b, and an annular recess 16e on the other end surface 16d. And a plurality of cutout recesses 16g along the circumferential direction in the annular standing wall 16f on the outer peripheral surface side of the annular recess 16e, and the upper end surface 16h of the annular standing wall 16f slightly protrudes from the end surface 16d, A through hole 16i that is continuous with the recess 16c is formed in the center of the end face 16d. The end surface 16b on the side where the recess 16c is formed has a plurality of recesses 16j that surround the recess 16c and extend in the circumferential direction. The recess 16j is used to make the thickness of the pressing member 16 uniform. It is meat stealing. The upper end surface 16h of the annular standing wall portion 16f is not slightly protruded from the end surface 16d, and conversely, the end surface 16d is configured to slightly protrude from the upper end surface 16h, or the end surface 16d and the upper end surface 16h are It can also be configured to have the same height.

  The elastic member 15 shown in FIG. 6 has the annular block portion 15a fitted in the annular recess 16e of the pressing member 16, and the protruding tongue piece portion 15e is fitted in the notched recess 16g of the pressing member 16. The press member 16 is fitted. In this state, the end surface 15 b of the elastic member 15 slightly protrudes from the upper end surface 16 h of the annular standing wall portion 16 f of the pressing member 16.

  As shown in FIG. 3, the rack support 14 inserts the bulging portion 14 j of the protruding support portion 14 e into the through hole 16 i of the pressing member 16, and brings the pressure receiving surface 14 c into contact with the end surface 15 b of the elastic member 15. The upper flat surface portion 14k of the bulging portion 14j of the protruding support portion 14e is brought into contact with the bottom surface of the concave portion 16c at the peripheral edge of the through hole 16i of the pressing member 16, so that the rack support body 14, the elastic member 15 and the pressing member 16 Are integrally assembled, and the rack guide 8 is formed.

  As shown in FIG. 2, the elastic means 18 is in contact with the bottom surface of the cylindrical recess 16 c of the pressing member 16 at one end, and is in contact with the lid member 9 at the other end, and between the rack guide 8 and the lid member 9. The coil spring 10 is provided with a coil spring 10 that is compressed between them, and the coil spring 10 elastically presses the arc concave surface 14 b of the rack support 14 against the arc convex surface 6 b of the rack bar 6 via the pressing member 16.

  The rack guide 8 has a holding hole with an annular gap Δ on the outer peripheral surface 14 g of the rack support 14 and the outer peripheral surface 16 a of the pressing member 16 with respect to the inner peripheral surface 2 d of the cylindrical portion 2 b that defines the holding hole 2 a of the housing 2. 2a and pressed against the rack bar 6 side by the coil spring 10 forming the elastic means 18 disposed between the pressing member 16 and the lid member 9, and the arc concave surface 14b of the rack support 14 is The circular arc convex surface 6b is elastically pressed. As shown in FIGS. 4 to 7, the pressing force of the coil spring 10 is fitted into the annular recess 16 e of the pressing member 16, and the elastic pressure contact surface 15 g is in contact with the orthogonal pressure receiving surface 14 h of the rack support 14. The annular block portion 15 a of the member 15 is compressed, and the orthogonal pressure receiving surface 14 h of the rack support 14 is connected to the upper end surface 16 h of the annular standing wall portion 16 f on the outer peripheral surface side of the annular recess 16 e of the pressing member 16 via the elastic member 15. 2 is brought into a state shown in FIG.

  In the steering apparatus 1 having the above configuration, as shown in FIG. 1, when the pinion 5 is rotated in the R direction by the steering operation, the rack bar 6 is linearly moved in the A direction through the engagement of the pinion 5 and the rack teeth 6a. As a result, the steering operation can be transmitted to the wheels of the automobile connected to the rack bar 6.

  In the steering device 1, the rack guide 8 contacts the arcuate convex surface 6 b of the rack bar 6 with the arcuate concave surface 14 b to guide the linear movement of the rack bar 6 in the A direction, and the pinion 5 and the rack are elastically generated by the elastic means 18. Cylindrical portion 2b that secures meshing with teeth 6a and defines holding hole 2a of housing 2 in the B direction following expansion and contraction of coil spring 10 as elastic means 18 following the displacement of rack bar 6 in the C direction. Move against.

  By the way, according to the rack guide 8, the rack support 14 made of synthetic resin having the arc concave surface 14b that slides and guides the rack bar 6 in contact with the arc convex surface 6b of the rack bar 6 is shown in FIGS. As shown in FIG. 3, the rack block 14 is formed on the orthogonal pressure receiving surface 15g protruding from the opening of the annular recess 16e, while the annular block 15a of the elastic member 15 is fitted in the annular recess 16e of the pressing member 16. Since the ring-shaped block portion 15a is compressed and tightly filled in the annular recess 16e under a load, the state shown in FIG. 2 is obtained, and repulsive elastic force is accumulated. By exhibiting a behavior like a rigid body, the pressure resistance of the rack support 14 is increased in the axial direction of the rack support 14 and the support capacity of the rack bar 6 is increased. The results, without the rack supports 14 produces a creep deformation, it is possible to avoid a decrease in bearing capacity due to creep deformation, the rack bar 6 can smoothly slide guides.

  As shown in FIG. 7B, in the above embodiment, the upper end surface 16h of the annular standing wall portion 16f is slightly protruded from the end surface 16d. Therefore, under the load, as shown in FIG. And the orthogonal pressure receiving surface 14h of the rack support 14, there is a slight gap, but in FIG. 7B, when the end surface 16d is configured to protrude slightly from the upper end surface 16h, the load Below, the end surface 16d abuts on the orthogonal pressure receiving surface 14h, and there is a slight gap between the upper end surface 16h and the orthogonal pressure receiving surface 14h of the rack support 14. In FIG. 7B, when the end surface 16d and the upper end surface 16h are configured to have the same height, the end surface 16d and the upper end surface 16h simultaneously abut on the orthogonal pressure receiving surface 14h under load. It will be.

  In addition, the rack guide 8 has a protruding tongue piece 15e of the elastic member 15 protruding from the outer peripheral surface 16a of the pressing member 16, the protruding tongue piece 15e is divided in the circumferential direction, and the outer peripheral surface of the rack guide 8 ( Since the outer peripheral surface 14g of the rack support member 14, the outer peripheral surface 16a of the pressing member 16) and the cylindrical inner peripheral surface 2d defining the holding hole 2a of the housing 2 are positioned within the annular gap Δ, the rack in FIG. Not only can the movement of the guide 8 in the direction of the rack bar 6 be prevented smoothly, but also the movement of the rack guide 8 to the cylindrical inner peripheral surface 2d that defines the holding hole 2a of the housing 2 is achieved. Since direct contact can be surely avoided, occurrence of collision noise with the housing 2 can be avoided.

  Next, a second embodiment of the rack guide according to the present invention will be described. In the first embodiment, as shown in FIGS. 4 to 7, an annular block portion 15 a of the elastic member 15 fitted in the orthogonal pressure receiving surface 14 h of the rack support 14 and the annular recess 16 e of the pressing member 16. In the second embodiment, as shown in FIG. 10 and FIG. 11, one of the annular block portions 45a of the elastic member 45 is shown. A pair of opposing projecting portions 45g formed integrally with the end surface 45b of the rack is fitted into a recess 44a formed opposite to each other with the pressure receiving surface 44c of the rack support 44 sandwiching the arc concave surface 44b. A rack guide 8 is used. That is, the rack support body 44 shown in FIG. 10 includes a pair of recesses 44a facing each other across the arc-shaped concave surface 44b with the pressure receiving surface 44c, and inner and outer peripheral wall surfaces 44d and 44e of the recess 44a are formed in an arc surface. Is done. In the present embodiment, components other than the rack support body 44 and the elastic member 45 are the same as those in the first embodiment, and thus the same reference numerals are given and detailed description thereof is omitted.

  As shown in FIG. 11, the elastic member 45 includes an annular block portion 45a, a pair of projecting portions 45g radially opposed to one end face 45b of the annular block portion 45a, and an annular block portion 45a. A plurality of (four in this example) projecting tongue pieces 45e projecting radially on the upper end side of the inner peripheral surface 45d via one end face 45b and a step 45c; The tip is formed on a circular arc surface 45f. Inner and outer peripheral surfaces 45d and 45h of the projecting portion 45g are formed in arcuate surfaces complementary to the recesses 44a of the rack support 44 shown in FIG.

  The elastic member 45 fits the annular block 45a into the annular recess 16e of the pressing member 16 shown in FIG. 7 and fits the protruding tongue piece 45e into the notch recess 16g of the pressing member 16. And is fitted to the pressing member 16.

  As shown in FIGS. 7 and 11, the rack support body 44 is formed by inserting the bulging portion 44j of the projecting support portion 44f into the through hole 16i of the pressing member 16 and inserting a pair of recesses 44a formed in the pressure receiving surface 44c. A pair of projecting portions 45g formed integrally with the end surface 45b of the annular block portion 45a of the elastic member 45 are fitted together, and the pressure receiving surface 44c is brought into contact with the outer peripheral surface 45h of the annular block portion 45a so that the projection The upper flat surface portion 44k of the bulging portion 44j of the support portion 44f is brought into contact with the bottom surface of the concave portion 16c at the peripheral edge of the through hole 16i of the pressing member 16, and the rack support body 44, the elastic member 45, and the pressing member 16 are brought together. The rack guide 8 is formed by assembling integrally. In this state, the end surface 45 b of the elastic member 45 slightly protrudes from the upper end surface 16 h of the annular standing wall portion 16 f of the pressing member 16.

  Also in the steering apparatus including the rack guide 8 shown in FIGS. 7 to 11, the rack support 44 made of a synthetic resin having an arc concave surface 44 b that slides and guides the rack bar 6 in contact with the arc convex surface 6 b of the rack bar 6. The annular block 45a of the elastic member 45 is fitted into the annular recess 16e of the pressing member 16, and the outer peripheral surface 45h projecting from the opening of the annular recess 16e contacts the pressure receiving surface 44c of the rack support 44. Therefore, under the load, the annular block 45a is compressed and tightly filled in the annular recess 16e, and the protrusion 45g is also tightly filled in the recess 44a of the rack support 44. The rebound elastic force is accumulated in the annular block portion 45a and the protruding portion 45g, and behaves like a rigid body. As a result, the pressure resistance of the rack support body 44 is further increased and the support capacity of the rack bar 6 is increased. As a result, the rack support body 44 does not undergo creep deformation and the like. By avoiding the decrease, the rack bar 6 can be smoothly slid and guided.

  The size of the pair of projecting portions 45g formed integrally with the end surface 45b of the annular block portion 45a of the elastic member 45 and the size of the recess 44a of the rack support body 44 to which the projecting portions 45g are fitted and held are determined. By appropriately changing, the rebound resilience accumulated in the protrusion 45g can be changed.

It is a whole sectional view showing a 1st embodiment of a rack guide concerning the present invention. It is an expanded sectional view which shows the rack guide of FIG. 1 and its vicinity. It is sectional drawing of the rack guide shown in FIG. It is a figure which shows the rack support body of the rack guide of FIG. 3, Comprising: (a) is a top view, (b) is a front view, (c) is a bottom view. It is the II sectional view taken on the line of Fig.4 (a). It is a figure which shows the elastic member of the rack guide of FIG. 3, Comprising: (a) is a top view, (b) is the II-II sectional view taken on the line of (a). It is a figure which shows the pressing member of the rack guide of FIG. 3, Comprising: (a) is a top view, (b) is the III-III sectional view taken on the line (a), (c) is a bottom view. It is a whole sectional view showing a 2nd embodiment of a rack guide concerning the present invention. It is an expanded sectional view which shows the rack guide of FIG. 8 and its vicinity. It is a figure which shows the rack support body of the rack guide of FIG. 9, Comprising: (a) is a front view, (b) is a bottom view. It is a figure which shows the elastic member of the rack guide of FIG. 9, Comprising: (a) is a top view, (b) is the IV-IV sectional view taken on the line (a). It is sectional explanatory drawing which shows the conventional steering device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering device 2 Housing 2a Holding hole 2b Cylindrical part 2c Main body 2d Inner peripheral surface 3 Bearing 4 Bearing 5 Pinion 6 Rack bar 6a Rack tooth 6b Arc convex surface 8 Rack guide 9 Cover member 10 Coil spring 12 Lock nut 14 Rack support body 14a End surface 14b Arc concave surface 14c Pressure receiving surface 14d Main body 14e Protruding support portion 14f Long groove 14g Outer peripheral surface 14h Orthogonal pressure receiving surface 14i Cylindrical portion 14j Swelling portion 14k Upper flat surface portion 14m Lower flat surface portion 14n Chamfered conical surface 14p Cutting groove 14q Bottom surface 14r Through hole 15 elastic member 15a annular block portion 15b end surface 15c stepped portion 15d outer peripheral surface 15e projecting tongue piece portion 15f arc surface 15g orthogonal pressure receiving surface 16 pressing member 16a outer peripheral surface 16b end surface 16c concave portion 16d end surface 16e annular concave portion 16f annular standing wall portion 16g notch Recess 16h Upper end surface 16i Through hole 6j recess 18 elastic means 44 rack support 44a recess 44b arc concave surface 44c pressure receiving surface 44d inner peripheral wall surface 44e outer peripheral wall surface 44f projecting support portion 44h orthogonal pressure receiving surface 44i cylindrical portion 44j bulging portion 44k upper flat surface portion 44m lower flat surface portion 44n Conical surface 44p slit groove 44r through hole 45 elastic member 45a annular block 45b end face 45c step 45d inner peripheral surface 45e protruding tongue piece 45f arc surface 45g protruding portion 45h outer peripheral surface

Claims (8)

A synthetic resin rack support having a concave surface that slides and guides the rack bar, and a pressure receiving surface that receives a pressing force toward the rack bar;
An elastic member disposed on the pressure receiving surface side of the rack support;
A pressing member that applies a pressing force toward the rack bar to the elastic member;
The elastic member has an annular block portion and a plurality of protruding tongue pieces protruding radially on the upper end side of the outer peripheral surface of the annular block portion,
The pressing member has an annular recess on an end surface facing the rack support, and a plurality of notch recesses formed in an annular standing wall portion on the outer peripheral surface side of the annular recess along the circumferential direction. The elastic member has the annular block portion fitted into the annular recess portion of the pressing member, and each of the plurality of protruding tongue pieces is formed as a notch recess in the annular standing wall portion of the pressing member. Fitted to each of the pressing members,
The rack support, the pressure-receiving surface, wherein a facet of the annular block portion of the elastic member, to be arranged is brought into contact with an end face protruding from the opening of said annular recess of said pressing member Features a rack guide.   The rack guide according to claim 1, wherein the pressure receiving surface includes an orthogonal pressure receiving surface orthogonal to a direction of a pressing force toward the rack bar.   The rack guide according to claim 1 or 2, wherein each of the protruding tongue piece portions of the elastic member has an arcuate surface and protrudes from an outer peripheral surface of the pressing member.   The said pressing member has a through-hole, The said rack support body is provided with the protrusion support part which penetrates the through-hole of this press member while being provided in the said pressure receiving surface integrally. The rack guide according to 2 or 3.   The protruding support portion of the rack support body includes a cylindrical portion having a diameter smaller than the diameter of the through hole of the pressing member, a slit groove formed on a free end side of the cylindrical portion, and the protruding support portion. The rack guide according to any one of claims 1 to 4, further comprising a bulging portion that prevents the protruding support portion from coming out of the through hole after being inserted into the through hole.   The elastic member integrally has a convex portion opposed to each other in the radial direction on one end face of the annular block portion, and the pressure receiving surface of the rack support is opposed to the radial direction across the concave surface. The rack guide according to any one of claims 1 to 5, further comprising a recess, wherein the elastic member is disposed by fitting the protrusion into a recess of a pressure receiving surface of the rack support. A housing having a cylindrical holding hole therein;
A pinion rotatably disposed in the housing and rotated by steering;
A rack bar having rack teeth meshing with the pinion;
The rack guide according to any one of claims 1 to 6, wherein the rack guide is movably disposed in the holding hole of the housing and movably guides and supports the rack bar.
Elastic means arranged in the holding hole and elastically pressing the rack teeth of the rack bar against the pinion via the rack guide;
The rack support body and the pressing member are disposed in the holding hole with an annular gap with respect to the inner surface of the holding hole of the housing, and the elastic member is formed in an annular shape of the pressing member by a pressing force applied to the rack bar. The rack support body is compressed by the pressure-receiving surface of the rack support member being brought into contact with the end surface of the annular recess portion of the pressing member while being compressed in the recess portion, and the rack support body is formed by the rebound elastic force stored in the elastic member. The rack and pinion type steering device is characterized in that the pressure resistance strength of the rack is increased and the support capacity of the rack bar is enhanced.   The rack and pinion type steering according to claim 7, wherein the elastic member is in contact with the inner surface of the holding hole of the housing with a margin by an arc surface of a protruding tongue piece protruding from the outer peripheral surface of the pressing member. apparatus.

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