CN206900466U - Housing for rack and pinion steering gear unit - Google Patents

Abstract

The utility model relates to a constitute the pinion-and-rack pair formula of the steering gear unit casing of the steering gear of car. The housing (10a) has a main housing section (11a) and a sub-housing section (12 a). A rib (24) is provided so as to bridge between the outer peripheral surface of the main housing section (11a) and the outer peripheral surface of the sub housing section (12 a). The reinforcing rib (24) has: a flat plate part (25) erected between the outer peripheral surface of the main receiving part (11a) and the outer peripheral surface of the sub receiving part (12 a); and a reinforcing portion (26) provided in a state of protruding from a side surface of the flat plate portion (25) in a plate thickness direction of the flat plate portion (25).

Description

Housing for rack and pinion steering gear unit

technical field

The utility model relates to a housing for a rack and pinion pair steering gear unit constituting a steering device of an automobile.

Background technique

As a steering device for automobiles, a rack and pinion type steering device is widely known as described in, for example, Patent Documents 1 and 2, and is widely practiced. FIG. 8 shows an example of a conventionally widely known rack and pinion steering device. In this steering device, rotation of a steering wheel 1 is transmitted to an input shaft 6 of a steering gear unit 5 via a steering shaft 2 , a universal joint 3 a , an intermediate shaft 4 , and a universal joint 3 b. Then, a pair of left and right tie rods 7, 7 is pushed and pulled along with the rotation of the input shaft 6, and a steering angle is applied to the steered wheels (normally, the front wheels). In addition, the illustrated example is also equipped with an electric power steering apparatus that uses an electric motor 8 as an auxiliary power source to achieve reduction in the force required to operate the steering wheel 1 . In addition, a tilt mechanism for adjusting the vertical position of the steering wheel 1 and a telescopic mechanism for adjusting the front and rear positions are also installed. However, since these mechanisms are not related to the gist of the present invention and are widely known in the past, detailed illustrations and descriptions are omitted.

The steering gear unit 5 is configured as shown in FIGS. 9 to 11, and converts the rotational motion of the input shaft 6 corresponding to the pinion shaft described in the technical solution into the linear motion of the rack shaft 9, and pushes and pulls a pair of tie rods. 7, 7. That is, the steering gear unit 5 includes a housing 10, a rack shaft 9, and an input shaft 6 as a pinion shaft. The casing 10 is manufactured by die-casting a light alloy such as an aluminum-based alloy, and includes a main housing portion 11 , an auxiliary housing portion 12 , and a cylinder portion 13 . The main housing portion 11 has a cylindrical shape with both ends opened in the longitudinal direction. The sub housing portion 12 is provided on the outer peripheral surface of the main housing portion 11 near one end in the longitudinal direction (the left end in FIGS. 9 to 11 ). The central axis of the main housing part 11 and the central axis of the auxiliary housing part 12 are in a positional relationship of mutually different plane straight lines. The inner space of the main housing part 11 and the inner space of the auxiliary housing part 12 communicate with each other. That is, the rear side (the upper side in FIG. 10 and the lower side in FIG. 11 ) of the middle portion of the sub-accommodating portion 12 is on the front side (the lower side in FIG. , the upper side of Figure 11) opening. The cylinder portion 13 is provided at a rear side portion of the main housing portion 11 near one end in the longitudinal direction. The front end portion of the cylinder portion 13 communicates with the inner space of the main housing portion 11 . A pair of mounting flanges 14 and 14 are fixedly provided at two positions spaced apart in the longitudinal direction on the outer peripheral surface of the main housing portion 11 . Furthermore, the case 10 is supported and fixed to the vehicle body (frame) by bolts or stud bolts inserted through the pair of mounting flanges 14 and 14 .

Rack teeth 15 are formed on the front side of the rack shaft 9 near one end in the longitudinal direction. The rack shaft 9 is in the shape of a round bar whose outer peripheral surface is cylindrical except for the portion where the rack teeth 15 are formed. A slide bearing 16 is provided between the rack shaft 9 and the main housing portion 11 near the other end in the longitudinal direction (the right end in FIGS. 9 to 11 ). In this way, the slide bearing 16 supports the rack shaft 9 inside the main housing portion 11 so as to be axially displaceable. In this state, both end portions of the rack shaft 9 are made to protrude from both end openings in the longitudinal direction of the main housing portion 11 .

The input shaft 6 meshes with the rack teeth 15 of the rack shaft 9 with the pinion teeth 17 provided at the distal end. The base end of the input shaft 6 protrudes out of the housing 10 from an opening provided at the upper end of the sub housing 12 . In this state, the input shaft 6 is rotatably supported by the sub housing portion 12 . A pressing block 18 is fitted in the cylinder portion 13 , and a cover body 19 is screwed to the rear opening of the cylinder portion 13 . A spring 20 is provided between the cover body 19 and the pressing block 18 to elastically press the pressing block 18 toward the rack shaft 9 . As a result, the rack shaft 9 is elastically pressed against the pinion teeth 17, the backlash at the meshing portion between the pinion teeth 17 and the rack teeth 15 is eliminated, and the portion of the rack shaft 9 close to one end in the longitudinal direction can be moved. Axial displacement support. In addition, with power transmission at the meshing portion of the rack teeth 15 and the pinion teeth 17, despite the force applied to the rack shaft 9 in a direction away from the input shaft 6, the meshing portion can be properly maintained. meshing state.

Base end portions of the tie rods 7 , 7 are connected to both end portions in the longitudinal direction of the rack shaft 9 via spherical joints 21 , 21 , respectively. The surroundings of the two spherical joints 21, 21 are covered by a pair of left and right bellows 22, 22. Stud bolts 23 , 23 are supported at the end portions of both tie rods 7 , 7 . By inserting the stud bolts 23, 23 into circular holes formed at the ends of the joint arms (not shown), and screwing nuts on the ends of the respective stud bolts 23, 23, the two tie rods 7 are connected to each other. , 7 can be combined with the articulated arm in a swingable and displaceable manner. In addition, the rack shaft 9 does not rotate around its central axis due to the meshing of the pinion teeth 17 and the rack teeth 15 .

When the input shaft 6 is rotated by operating the steering wheel 1 in order to impart a steering angle to a pair of left and right steering wheels using the steering device equipped with the above-mentioned steering gear unit 5 , the meshing of the pinion teeth 17 and the rack teeth 15 , the rack shaft 9 is displaced in the axial direction. And push and pull the two steering tie rods 7 and 7 combined at both ends of the length direction of the rack shaft 9, so that the two articulated arms are oscillated and displaced, and the left and right pairs of joints on which the two articulated arms are fixed are respectively connected with the center pin. Swing displacement for the center. Then, desired steering angles are given to the two steered wheels rotatably supported by the two joints via rolling bearing units, respectively.

In the case 10 constituting the above-mentioned rack and pinion steering gear unit 5 , it is desired to further increase the rigidity of the sub housing portion 12 with respect to the main housing portion 11 . That is, as described above, when the steering gear unit 5 is in operation, along with the rotation of the input shaft 6, on the input shaft 6 and the rack shaft 9, the meshing portion between the pinion teeth 17 and the rack teeth 15 acts reversely. force. Based on this opposing force, a force in a direction away from each other in the front-rear direction is applied to the pinion teeth 17 and the rack teeth 15 (the input shaft 6 and the rack shaft 9 ). In particular, in the case of a steering device equipped with a column-assist type electric power steering apparatus that applies assist power generated by the electric motor 8 to the steering shaft 2 as shown in FIG. The reverse force becomes larger, and the force applied to the input shaft 6 and the rack shaft 9 in a direction away from each other in the front-rear direction also becomes larger. The force applied to the input shaft 6 is applied to the sub-accommodating portion 12 via a bearing that rotatably supports the input shaft 6 , and the force applied to the rack shaft 9 is applied to the main accommodating portion 11 via the sliding bearing 16 and the pressing block 18 . Also, when the steering gear unit 5 is in operation, a force in the left-right direction (the width direction of the vehicle) is applied to the input shaft 6 from the meshing portion along with the linear motion of the rack shaft 9 . Then, when the force in the left-right direction is applied to the sub-accommodating portion 12 via the bearing, the sub-accommodating portion 12 tends to collapse relative to the main accommodating portion 11 in the lateral direction (the longitudinal direction of the main accommodating portion 11 ). Therefore, it is important to further increase the rigidity of the sub housing part 12 with respect to the main housing part 11 from the viewpoint of achieving improvement in the durability of the steering gear unit 5. In addition, it is also desirable to further increase the rigidity of the sub-accommodating portion 12 relative to the main accommodating portion 11 from the viewpoint of realizing an improvement in the response to the steering angle of the steering wheels based on the operation of the steering wheel 1 .

Patent Documents 1 to 2 describe a structure in which the main storage unit is bridged between the outer peripheral surface of the main storage unit and the outer peripheral surface of the sub storage unit, and parallel to the central axis of the main storage unit and the central axis of the sub storage unit. Ribs are provided. However, in the case of the structures described in Patent Documents 1 and 2, there is room for further improvement in terms of further improving the rigidity of the sub-accommodating portion with respect to the main accommodating portion. In addition, Patent Documents 1 to 2 describe a technology in which a rib is provided in a state of spanning between the main housing part and the mounting flange, and is inclined with respect to the central axis of the main housing part, so that the mounting flange Rigidity in the front-rear direction and the up-down direction on the main housing portion is improved. It is also conceivable to apply the technology described in such patent documents 1 to 2 to the joint part of the main housing part and the auxiliary housing part, but because the outer peripheral surface of the main housing part is opposite to the auxiliary housing part in the radial direction Since the cylinder portion exists in the side portion, it may be difficult to apply the techniques described in Patent Documents 1 and 2 as they are. Furthermore, in the case of the technique described in Patent Document 1, a plurality of ribs are provided, which is disadvantageous in terms of weight reduction.

existing technical documents

Patent Documents

Patent Document 1: International Publication No. 2007/060887

Patent Document 2: Japanese Patent Application Laid-Open No. 2012-250675

Utility model content

The problem that the utility model intends to solve

The utility model is made in view of the above situation, in order to realize the structure of the housing for the rack-and-pinion auxiliary steering gear unit, which can further improve the rigidity of the sub-accommodating part relative to the main accommodating part while suppressing the increase in weight. The utility model issued.

solutions to problems

The housing for the rack and pinion steering gear unit of the present invention includes a main housing part, a secondary housing part, and a reinforcing rib.

The main housing part is a cylindrical shape with both ends open, and accommodates a rack shaft with rack teeth formed on a part of the side surface in the axial direction so as to be able to displace in the axial direction. It is stored in a state where both ends protrude from the openings at both ends.

The central axis of the sub-accommodating portion is located at a straight line out of plane with respect to the central axis of the main accommodating portion, a part of which is open to the main accommodating portion, and a pinion shaft provided with pinion teeth at a terminal portion thereof is placed inside. It is supported rotatably.

The reinforcing rib is provided in a state of bridging between the outer peripheral surface of the main housing part and the outer peripheral surface of the auxiliary housing part.

In particular, in the housing for the rack and pinion steering gear unit of the present invention, the reinforcing rib has: a flat plate portion, which is bridged between the outer peripheral surface of the main receiving part and the outer peripheral surface of the auxiliary receiving part. In between, the rigidity against the collapse of the sub-accommodating portion in the longitudinal direction of the main accommodating portion is improved. The rack teeth on the top and the pinion teeth provided on the pinion shaft are collapsed by the reverse force of the meshing part; The direction (not limited to the direction at right angles to the flat plate portion) protrudes to improve the collapse of the sub-accommodating portion based on the reverse force in the direction of action of the reverse force and in the direction of torsion. rigidity.

In the case of implementing the housing for the rack and pinion steering gear unit of the present invention as described above, it is preferable that the central axis of the flat plate portion and the main housing portion and the central axis of the sub housing portion set in parallel.

In addition, it is preferable that the reinforcing portion is arranged at right angles to the flat plate portion.

In addition, it is preferable that the reinforcement part is provided in a direction from a side surface of the flat plate part toward a side where the sub-accommodating part is provided.

In addition, it is preferable that the reinforcing portion is provided in a state of being bent from an end edge of the flat plate portion.

In addition, it is preferable that both ends of the reinforcement part are respectively connected to the outer peripheral surface of the main storage part and the outer peripheral surface of the auxiliary storage part.

Utility Model Effect

According to the housing for the rack-and-pinion steering gear unit of the present invention as described above, it is possible to further improve the rigidity of the sub-accommodating portion with respect to the main accommodating portion while suppressing an increase in weight. Therefore, when the rack and pinion steering gear unit operates, the steering gear unit can be realized despite the force applied to the main housing part and the sub housing part based on the force acting on the meshing part between the pinion teeth and the rack teeth. improvement in durability. In addition, it is possible to improve the response to the steering angle given to the steered wheels based on the manipulation of the steering wheel.

Description of drawings

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state viewed from a side opposite to FIG. 1 in the front-rear direction.

FIG. 3 is a top view of FIG. 1 .

FIG. 4 is a rear view of the state seen from the bottom of FIG. 3 .

FIG. 5A is a sectional view taken along line aa of FIG. 4 .

FIG. 5B is an enlarged view of part b of FIG. 5A .

Fig. 6 is a c-direction view of Fig. 2 .

FIG. 7A is a diagram similar to FIG. 5B showing a modified example of the shape of the reinforcing portion.

FIG. 7B is a diagram similar to FIG. 5B showing a modified example of the shape of the reinforcing portion.

FIG. 7C is a diagram similar to FIG. 5B showing a modified example of the shape of the reinforcing portion.

8 is a partially cutaway side view showing an example of a steering device for an automobile including a rack-and-pinion steering gear unit.

Fig. 9 is a partially cutaway front view showing an example of a conventional structure.

FIG. 10 is a partially cutaway plan view viewed from above in FIG. 9 .

Fig. 11 is a dd sectional view of Fig. 9 .

Explanation of reference signs

1 steering wheel

2 steering shaft

3a, 3b universal joint

4 intermediate shaft

5 Steering gear unit

6 input shaft

7 tie rod

8 electric motor

9 rack shaft

10, 10a Shell

11, 11a Main Containment Unit

12, 12a Secondary Containment

13 Cylinder

14 Mounting flange

15 rack teeth

16 plain bearing

17 pinion teeth

18 Press block

19 cover

20 springs

21 ball joint

22 Bellows

23 Stud bolts

24 ribs

25 flat part

26 Strengthening Department

detailed description

1 to 7 show the first embodiment of the present invention. In addition, the housing for the rack-and-pinion steering gear unit according to the present embodiment is characterized in that, by studying the shape of the rib 24, it is possible to make the sub-accommodating portion 12a relative to the main body while suppressing an increase in weight. A structure in which the rigidity of the housing portion 11a is further improved. The structure and function of other parts are the same as those of the conventionally known housing for the rack and pinion steering gear unit including the conventional structure shown in FIGS. 9 to 11 described above.

The casing 10 a of the present embodiment is manufactured by die-casting a light alloy such as an aluminum-based alloy. The housing 10 a includes a main housing part 11 a , a sub housing part 12 a , and a cylinder part 13 . The main housing portion 11a has a cylindrical shape with both ends opened in the longitudinal direction. The sub-accommodating portion 12a is provided on the outer peripheral surface of the main accommodating portion 11a near one end in the longitudinal direction (the right end in Figs. 1, 3 and 4, and the left end in Fig. 2). The central axis of the main housing part 11a and the central axis of the auxiliary housing part 12a are in a positional relationship of different planes. The rear side (lower side in FIG. 3 , right side in FIGS. 5 and 6 ) of the middle portion of the sub-accommodating portion 12a is on the front side (upper side in FIG. , the left side of Fig. 5, 6) opening. The cylinder part 13 is provided in the rear part of the part close to one end in the longitudinal direction of the main housing part 11a. The front end portion of the cylinder portion 13 communicates with the inner space of the main housing portion 11a. A pair of mounting flanges 14 and 14 are fixedly provided at two positions spaced apart in the longitudinal direction on the outer peripheral surface of the main housing portion 11a. Furthermore, the case 10a is supported and fixed to the vehicle body (frame) by bolts or stud bolts inserted through the pair of mounting flanges 14 and 14 .

In addition, in the present embodiment, ribs 24 having a substantially triangular shape in front view are provided in a cross-sectional L-shape in a state of bridging between the outer peripheral surface of the main housing portion 11a and the outer peripheral surface of the sub housing portion 12a. The rib 24 includes a flat plate portion 25 and a reinforcement portion 26 . The thickness dimension of the flat plate portion 25 is constant, and the portion between the outer peripheral surface of the main housing portion 11a and the outer peripheral surface of the auxiliary housing portion 12a is formed by bridging the central axis of the main housing portion 11a and the central axis of the auxiliary housing portion 12a. The state of the part between the one side where the angle is an obtuse angle is provided parallel to the central axis of the main housing part 11a and the central axis of the sub housing part 12a. In other words, the flat plate portion 25 is erected from the outer peripheral surface of the main housing portion 11a in a direction parallel to a virtual plane including the central axis of the sub housing portion 12a. In addition, the height dimension of the flat plate portion 25 from the outer peripheral surface of the main housing portion 11a increases as it approaches the sub housing portion 12a. The reinforcing portion 26 is provided on the entire front end edge (side surface of the upper end portion, upper end edge in FIG. 5 ) of the flat plate portion 25 in a state bent at right angles from the front end edge to the front. The thickness dimension of the reinforcing portion 26 is, for example, about 1.2 to 2 times larger than the thickness dimension of the flat plate portion 25 . However, as shown in FIG. 7A , the reinforcing portion 26 can also be provided in a state bent rearward at a right angle from the distal edge of the flat plate portion 25 . As shown in FIG. 7B , the reinforcing portion 26 may also be provided on the flat plate portion 25 at right angles (protruding from the end edge of the flat plate portion 25 to both front and back), and the cross-sectional shape of the rib 24 may be T-shaped. As shown in FIG. 7C , the reinforcing portion 26 can also be provided on the flat plate portion 25 at a right angle to the front from the portion near the tip of the front side surface of the flat plate portion 25 . In addition, the reinforcing portion 26 does not necessarily have to be provided at a right angle to the flat plate portion 25 . That is, the angle formed by the flat plate portion 25 and the reinforcing portion 26 is in the range of more than 0° and less than 180°, and is appropriately determined according to the shape of the portion where the rib 24 is provided and the degree of rigidity required. In short, in the case of the present embodiment, both ends of the reinforcement part 26 are connected to the outer peripheral surface of the main housing part 11a and the outer peripheral surface of the sub housing part 12a. In addition, in the case of the present embodiment, the thickness and the amount of protrusion (the amount of protrusion from the side surface of the flat plate portion 25) of the reinforcing portion 26 are constant over the entire length of the flat plate portion 25. Increase the two ends, etc., and change appropriately.

According to the casing 10a of the present embodiment configured as above, since the reinforcing rib 24 is provided in a state spanning between the outer peripheral surface of the main housing portion 11a and the outer peripheral surface of the sub housing portion 12a, the sub housing portion can be sufficiently secured. 12a relative to the rigidity of the main housing portion 11a. In particular, in the case of this embodiment, since the rib 24 (flat plate portion 25) has a substantially triangular shape in front view, it is possible to improve the direction in which the subaccommodating portion 12a collapses in the width direction (shown by arrow α in FIG. 4 ). direction) rigidity. In addition, in the case of the present embodiment, not only the flat plate portion 25 has a substantially triangular shape in front view, but also the reinforcing portion 26 is provided in a bent state from the end edge of the flat plate portion 25 . As a result, the joint portion between the main housing portion 11a and the auxiliary housing portion 12a (indicated by point P in FIG. The cross-sectional area of the farthest part. Therefore, the rigidity against the subaccommodating portion 12 a collapsing in the width direction can be improved without needlessly increasing the plate thickness of the flat plate portion 25 . Therefore, it is possible to suppress an increase in the weight of the casing 10 a compared to the case of simply providing thicker ribs.

In the case where the sub-accommodating portion 12a tends to collapse in the front-back direction (in the direction indicated by arrow β in FIG. The part 26 is supported between the main housing part 11a and the sub housing part 12a. Especially in the case of the present embodiment, one end of the reinforcing portion 26 is connected to a position (higher position) sufficiently far away from the joining portion (point P) on the outer peripheral surface of the sub-accommodating portion 12a, and the reinforced The other end of the portion 26 is connected to a position sufficiently separated from the joint portion (point P) on the outer peripheral surface of the main housing portion 11a. Therefore, the rigidity against the subaccommodating portion 12a collapsing in the front-rear direction can be effectively increased. In addition, the rigidity in the torsional direction can also be improved. In addition, the rib 24 can be manufactured by integrally manufacturing the case 10a when die-casting the light alloy, or joining members formed by bending metal plates by welding or the like. When the rib 24 is manufactured integrally with the housing 10a by die-casting, it can be manufactured without complicated processing such as dividing the mold to manufacture the rib 24, for example.

This application is based on the JP Patent application 2014-088665 for which it applied on April 23, 2014, The content is taken in here as a reference.

Claims (6)

1. A housing for a rack and pinion steering gear unit, comprising: The main accommodating part is a cylindrical shape with both ends open, and accommodates a rack shaft with rack teeth formed on a part of the side surface in the axial direction so that the rack shaft can be displaced in the axial direction. It is stored in a state where both ends protrude from the openings at both ends; The sub-accommodating part has a central axis at a position on a straight line that is out of plane with respect to the central axis of the main accommodating part, a part of which is open to the main accommodating part, and rotates a pinion shaft provided with pinion teeth at the end part inside. freely supported; and a reinforcing rib provided in a state of bridging between the outer peripheral surface of the main housing part and the outer peripheral surface of the sub housing part, The reinforcing rib has: a flat plate portion, which is bridged between the outer peripheral surface of the main housing part and the outer peripheral surface of the auxiliary housing part, and improves the inversion of the auxiliary housing part in the longitudinal direction of the main housing part. The rigidity of the collapse is based on the engagement of the rack teeth provided on the rack shaft with the pinion teeth provided on the pinion shaft as the pinion shaft rotates. and a reinforcing portion protruding from the side surface of the flat plate portion in the plate thickness direction of the flat plate portion to improve the resistance to the sub-accommodating portion based on the reverse force. , the rigidity of collapse in the direction of action of said opposing force and in the direction of torsion. 2. The housing for the rack and pinion steering gear unit according to claim 1, The flat plate part is arranged parallel to the central axis of the main housing part and the central axis of the auxiliary housing part. 3. The housing for the rack and pinion steering gear unit according to claim 1, The reinforcing part is arranged at right angles to the flat part. 4. The housing for the rack and pinion steering gear unit according to claim 1, The reinforcing portion is provided from a side surface of the flat plate portion in a direction toward a side where the sub-accommodating portion is provided. 5. The housing for the rack and pinion steering gear unit according to claim 1, The reinforcing portion is provided in a state of being bent from an end edge of the flat plate portion. 6. The housing for the rack and pinion steering gear unit according to claim 1, Both ends of the reinforcement part are respectively connected to the outer peripheral surface of the main housing part and the outer peripheral surface of the auxiliary housing part.