JP7029987B2 - Manufacturing method of steering device - Google Patents

Description

The present invention relates to a method of manufacturing a steering device in which a rack bar is supported by a bush on a rack housing.

As a background technique in the present technical field, a rack and pinion type steering gear unit described in Japanese Patent Application Laid-Open No. 2016-020146 (Patent Document 1) is known. Patent Document 1 aims to realize a structure that can prevent the elastic ring from being damaged when the rack bush is assembled to the housing and can simplify the shape of the bush body. The rack and pinion type steering gear unit of Patent Document 1 does not have a concave groove for locking the inner diameter portion of the elastic ring on the outer peripheral surface of the bush body, and the outer diameter side locking concave groove is provided on the inner peripheral surface of the housing. Is formed, and the outer diameter side portion of the elastic ring is locked in the outer diameter side locking concave groove. The entire portion of the bush body near the outer diameter is inserted into the positioning concave groove formed on the inner peripheral surface of the housing to perform axial positioning of the bush body (see summary).

Japanese Unexamined Patent Publication No. 2016-02014

When two types of steering devices with different specifications are manufactured on the same production line, there is a possibility that parts of the steering device of one specification may be assembled to the steering device of the other specification. In the steering device of Patent Document 1, when the first specification and the second specification are mixed in the same production line, the bush body of the second specification is assembled to the housing of the first specification, or the second specification is attached to the housing of the second specification. There is a possibility of assembling the bush body of. However, Patent Document 1 does not give consideration to preventing such erroneous assembly.

An object of the present invention is to provide a method for manufacturing a steering device capable of preventing erroneous assembly of parts in a production line in which parts having a plurality of specifications are mixed.

According to the present invention, in one aspect thereof, the steering device has the following configuration.

The first bush of the steering device of the first specification has a flange portion that does not fit into the flange portion accommodating portion of the second rack housing so that the first bush cannot be properly assembled to the second rack housing. On the other hand, the second bush of the steering device of the second specification has a configuration in which the main body portion does not fit into the main body portion accommodating portion of the first rack housing so that the second bush cannot be properly assembled to the first rack housing.

According to the present invention, it is possible to prevent erroneous assembly of parts in a production line in which parts having a plurality of specifications are mixed.

It is a top view which shows the appearance of the steering apparatus 1A, 1B which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the rack housing (first rack housing) 30A, the bush 40A, and the rack bar 10A in the steering apparatus 1A of the first specification. It is sectional drawing which shows the structure of the rack housing 30B, the bush 40B, and the rack bar 10B in the steering apparatus 1B of the second specification. It is a figure which shows the manufacturing process of a steering apparatus 1A. It is a figure which shows the manufacturing process of a steering apparatus 1B. It is a figure which shows the assembly state which the 1st bush 40A was erroneously assembled to the 2nd rack housing 30B, and is the assembly state when the 2nd flange part accommodating part axial length L33Bb is shorter than the 1st flange part axial length L40Ab. It is a figure which shows. It is a figure which shows the state which the 2nd bush 40B is erroneously assembled to the 1st rack housing 30A, and is the assembly when the 2nd bush main body part axial length L40Ba is longer than the 1st bush main body part accommodating part axial length L33Aa. It is a figure which shows the state. It is an external view of the 1st bush 40A seen from the radial direction. It is an external view which looked at the 1st bush 40A from the right side of FIG. It is an external view which looked at the 1st bush 40A from the left side of FIG. It is an external view of the 2nd bush 40B seen from the radial direction. It is an external view which looked at the 2nd bush 40B from the right side of FIG. It is an external view which looked at the 2nd bush 40B from the left side of FIG. It is a figure which shows the state which the 2nd bush which has the 2nd small diameter part 40Ba1 is erroneously assembled to the 1st rack housing 30A. It is a figure which shows the state which attached the 1st bush 40A provided with the 1st small diameter part 40Aa1 to the 1st rack housing 30A.

FIG. 1 is a plan view showing the appearance of steering devices 1A and 1B according to an embodiment of the present invention.

In this embodiment, two types of steering devices, the steering device 1A of the first specification and the steering device 1B of the second specification, are targeted. The steering device 1A and the steering device 1B have different structures in various places on the device, but are produced on the same production line. In this embodiment, the rack bar and the rack bar for steering the steering wheel are racked in the steering device 1A of the first specification and the steering device 1B of the second specification, which are produced in a mixed manner on the same production line. The present invention relates to a configuration and a manufacturing method for preventing erroneous assembly with a bush supporting the housing.

The steering devices 1A and 1B assist the steering mechanism 2 and the rack bars 10A and 10B that transmit the rotation of the steering wheel (not shown) steered by the driver to the rack bars 10A and 10B configured to steer the steering wheels. It is provided with an assist mechanism 3 for applying force.

The steering devices 1A and 1B targeted by this embodiment may be referred to as a power steering device.

A tie rod (not shown) is connected to both ends of the rack bars 10A and 10B, and a knuckle arm (not shown) is further connected to the tie rod. The linear motion along the longitudinal direction of the rack bars 10A and 10B is transmitted to a wheel (not shown) supported by the knuckle arm via the tie rod and the knuckle arm, and is converted into a steering motion of the wheel.

The steering mechanism 2 has a steering input shaft 80 connected to the steering wheel and a pinion (not shown) that rotates with the steering input shaft 80. The pinion meshes with a rack (not shown) formed on the outer periphery of the rack bars 10A and 10B. The assist mechanism 3 includes an electric motor 40 and controls the electric motor 40 to apply an assist force to the rack bars 10A and 10B. In this embodiment, the steering mechanism 2 and the assist mechanism 3 are assumed to have the same specifications, but may have different specifications.

The rack bars 10A and 10B have a speed reducer on a pinion shaft (not shown), and steer the steering wheels (steering wheels) as the rack bars 10A and 10B move along the longitudinal direction. As for the rack bar, the rack bar of the first specification (first rack bar) 10A is assembled to the steering device 1A of the first specification, and the rack bar of the second specification (second rack bar) is assembled to the steering device 1B of the second specification. Rack bar) 10B is assembled.

The configurations of the rack housings 30A and 30B, the bushes 40A and 40B, and the rack bars 10A and 10B will be described with reference to FIGS. 2 and 3 together with FIG. FIG. 2 is a cross-sectional view showing the configuration of the rack housing 30A, the bush 40A, and the rack bar 10A in the steering device 1A of the first specification. FIG. 3 is a cross-sectional view showing the configuration of the rack housing 30B, the bush 40B, and the rack bar 10B in the steering device 1B of the second specification. Note that FIG. 2 shows a cross section parallel to the first reference axis 10Aa along the longitudinal direction of the first rack bar 10A and including the first reference axis 10Aa. Further, FIG. 3 shows a cross section parallel to the second reference axis 10Ba along the longitudinal direction of the second rack bar 10B and including the second reference axis 10Ba.

The steering devices 1A and 1B have rack housings 30A and 30B for accommodating the respective components. The rack housings 30A and 30B are housing portions that accommodate at least a part of the rack bars 10A and 10B so that the rack bars 10A and 10B can move in the longitudinal direction (axial direction of the rack bar). The rack housings 30A and 30B include rack housing main bodies 31A and 31B, rack bar accommodating portions 32A and 32B, and bush accommodating portions 33A and 33B. As for the rack housing, the rack housing of the first specification (first rack housing) 30A is assembled to the steering device 1A of the first specification, and the rack housing of the second specification (second rack housing) is assembled to the steering device 1B of the second specification. Rack housing) 30B is assembled. Further, the rack housings 30A and 30B are provided with a gear housing portion 34 (see FIG. 1) for accommodating a speed reducer (not shown).

The rack housing main body portions 31A and 31B have a tubular shape and include a pair of end portions, the first end portions 31Aa and 31Ba and the second end portions 31Ab and 31Bb (see FIG. 1). In the rack housing main bodies 31A and 31B, the main body of the first rack housing 30A is the first rack housing main body 31A, and the main body of the second rack housing 30B is the second rack housing main body 31B. The first end 31Aa and the second end 31Ab of the first rack housing body 31A are the first end 31Aa of the first rack housing body and the second end 31Ab of the first rack housing body 31Ab (see FIG. 1), respectively. Call and explain. Further, the first end 31Ba and the second end 31Bb of the second rack housing main body 31B are the first end 31Ba of the second rack housing main body and the second end 31Bb of the second rack housing main body, respectively (see FIG. 1). ) To explain.

The rack bar accommodating portions (outer peripheral walls of the rack bar accommodating space) 32A and 32B are provided inside the rack housing main body portions 31A and 31B, and are configured to be able to accommodate the rack bars 10A and 10B. As for the rack bar accommodating portions 32A and 32B, the first rack bar accommodating portion 32A is provided in the first rack housing 30A, and the second rack bar accommodating portion 32B is provided in the second rack housing 30B.

Here, the above-mentioned first reference axis line 10Aa and the first reference axis line 10Ba will be described. The first reference axis 10Aa passes through the center of the inner peripheral circle of the first rack bar accommodating portion 32A in a cross section perpendicular to the moving direction MA of the first rack bar 10A with respect to the first rack housing 30A, and the first rack. It is an axis parallel to the moving direction MA of the bar 10A. The second reference axis 10Ba passes through the center of the inner peripheral circle of the second rack bar accommodating portion 32B in a cross section perpendicular to the moving direction MB of the second rack bar 10B with respect to the second rack housing 30B, and the second rack. It is an axis parallel to the moving direction MB of the bar 10B. In this embodiment, the first reference axis 10Aa coincides with the central axis of the first rack bar 10A, and the first reference axis 10Ba coincides with the central axis of the second rack bar 10B.

Further, the radius r32A of the first rack bar accommodating portion 32A centered on the first reference axis 10Aa is defined as the radius of the first rack bar accommodating portion, and the radius of the second rack bar accommodating portion 32A centered on the second reference axis 10Ba. r32B is defined as the radius of the second rack bar accommodating portion.

Hereinafter, the bush accommodating portions 33A and 33B and the bushes 40A and 40B according to the present invention will be described.

First, the bush accommodating portions 33A and 33B will be described.

The bush accommodating portion 33A is provided in the steering device 1A of the first specification as the first bush accommodating portion of the first specification, and the bush accommodating portion 33B is provided in the steering device 1B of the second specification as the second bush accommodating portion of the second specification. Be done.

The first bush accommodating portion 33A is provided inside the first rack housing main body portion 31A and is configured to be capable of accommodating the first bush 40A. The first bush accommodating portion 33A includes a first bush main body accommodating portion 33Aa and a first flange accommodating portion 33Ab. The second bush accommodating portion 33B is provided inside the second rack housing main body portion 31B and is configured to be capable of accommodating the second bush 40B. The second bush accommodating portion 33B includes a second bush main body accommodating portion 33Ba and a second flange accommodating portion 33Bb.

The first bush main body accommodating portion 33Aa is provided in the first bush accommodating portion 33A, and the main body portion (first bush main body portion) 40Aa of the first bush 40A of the first specification is arranged. It constitutes a part accommodating part. The second bush main body accommodating portion 33Ba is provided in the second bush accommodating portion 33B, and the main body portion (second bush main body portion) 40Ba of the second bush 40B of the second specification is arranged. It constitutes the main body accommodating part.

Here, the length L33Aa of the first bush main body accommodating portion 33Aa in the direction along the first reference axis 10Aa is defined as the axial length of the first bush main body accommodating portion, and the second bush main body accommodating portion 33Ba is second. The length L33Ba in the direction along the reference axis 10Ba is defined as the axial length of the second bush main body accommodating portion. Further, the radius r33Aa centered on the first reference axis 10Aa of the first bush main body accommodating portion 33Aa is defined as the radius of the first bush main body accommodating portion 33Aa, and the second reference axis 10Ba of the second bush main body accommodating portion 33Ba is defined. The radius r33Ba at the center is defined as the radius of the second bush main body accommodating portion.

The first bush main body accommodating portion 33Aa is provided between the first rack bar accommodating portion 32A and the first rack housing first end portion 31Aa in the direction along the first reference axis 10Aa. Further, the first bush main body accommodating portion 33Aa is provided inside the first rack housing main body portion 31A, and the first bush main body accommodating portion radius r33Aa has a shape larger than the first rack bar accommodating portion radius r32A. There is.

The second bush main body accommodating portion 33Ba is provided between the second rack bar accommodating portion 32B and the second rack housing first end portion 31Ba in the direction along the second reference axis 10Ba. Further, the second bush main body accommodating portion 33Ba is provided inside the second rack housing main body portion 31B, and the second bush main body accommodating portion radius r33Ba has a shape larger than the second rack bar accommodating portion radius r32B. There is.

That is, the inner diameter of the first bush main body accommodating portion (twice the radius r33Aa) is larger than the inner diameter of the first rack bar accommodating portion (twice the radius r32A). Further, the inner diameter of the second bush main body accommodating portion (twice the radius r33Ba) is larger than the inner diameter of the second rack bar accommodating portion (twice the radius r32B). The first bush main body accommodating portion 33Aa is formed as a concave portion recessed from the inner peripheral surface of the first rack bar accommodating portion 32A toward the outer side in the radial direction about the first reference axis 10Aa, and the second bush main body portion is formed. The accommodating portion 33Ba is formed as a recess recessed from the inner peripheral surface of the second rack bar accommodating portion 32B toward the outside in the radial direction about the second reference axis 10Ba.

The first flange portion accommodating portion 33Ab is provided in the first bush accommodating portion 33A, and constitutes the flange portion accommodating portion of the first specification in which the flange portion (first flange portion) 40Ab of the first bush 40A is arranged. The second flange portion accommodating portion 33Bb is provided in the second bush accommodating portion 33B, and constitutes the flange portion accommodating portion of the second specification in which the flange portion (second flange portion) 40Bb of the second bush 40B is arranged.

Here, the length L33Ab of the first flange portion accommodating portion 33Ab in the direction along the first reference axis 10Aa is defined as the axial length of the first flange portion accommodating portion 33Bb, and the second reference axis 10Ba of the second flange portion accommodating portion 33Bb is defined. The length L33Bb in the direction along the above is defined as the axial length of the second flange portion accommodating portion. Further, the radius r33Ab centered on the first reference axis 10Aa of the first flange portion accommodating portion 33Ab is defined as the radius of the first flange portion accommodating portion, and is centered on the second reference axis 10Ba of the second flange portion accommodating portion 33Bb. The radius r33Bb is defined as the radius of the second flange portion accommodating portion.

The first flange portion accommodating portion 33Ab is provided between the first bush main body accommodating portion 33Aa and the first rack housing first end portion 31Aa in the direction along the first reference axis 10Aa. Further, the first flange portion accommodating portion 33Ab is provided inside the first rack housing main body portion 31A, and the first flange portion accommodating portion radius r33Ab has a shape larger than the first bush main body accommodating portion radius r33Aa. .. The second flange portion accommodating portion 33Bb is provided between the second bush main body accommodating portion 33Ba and the second rack housing first end portion 31Ba in the direction along the second reference axis 10Ba. Further, the second flange portion accommodating portion 33Bb is provided inside the second rack housing main body portion 31B, and the second flange portion accommodating portion radius r33Bb has a shape larger than the second bush main body accommodating portion radius r33Ba. ..

That is, the inner diameter of the first flange portion accommodating portion 33Ab (twice the radius r33Ab) is larger than the inner diameter of the first bush main body accommodating portion 33Aa (twice the radius r33Aa). Further, the inner diameter of the second flange portion accommodating portion 33Bb (twice the radius r33Bb) is larger than the inner diameter of the first bush main body accommodating portion 33Ba (twice the radius r33Ba).

Next, the bushes 40A and 40B will be described.

The bushes 40A and 40B include bush body portions 40Aa and 40Ba and flange portions 40Ab and 40Bb. The bushes 40A and 40B include a first specification first bush 40A assembled to the first steering device 1A and a second specification second bush 40B assembled to the second steering device 1B.

The first bush 40A includes a bush main body portion (first bush main body portion) 40Aa of the first specification and a flange portion (first flange portion) 40Ab of the first specification. The first bush 40A can be accommodated in the first bush accommodating portion 33A and has a tubular shape. The first bush 40A is configured to be able to support the first rack bar 10A on the first rack housing 30A with the first rack bar 10A inserted. The second bush 40B includes a bush main body portion (second bush main body portion) 40Ba of the second specification and a flange portion (second flange portion) 40Bb of the second specification. The second bush 40B can be accommodated in the second bush accommodating portion 33B and has a tubular shape. The second bush 40B is configured to be able to support the second rack bar 10B on the second rack housing 30B with the second rack bar 10B inserted.

Here, the length L40Aa of the first bush main body 40Aa in the direction along the first reference axis 10Aa is defined as the axial length of the first bush main body 40Aa, and the direction of the second bush main body 40Ba along the second reference axis 10Ba. L40Ba is defined as the axial length of the second bush main body.

Further, the radius r40Aa of the outer shape (that is, the outer circumference) of the first bush main body 40Aa centered on the first reference axis 10Aa of the first bush main body 40Aa is defined as the radius of the first bush main body, and the second bush main body 40Ba. The radius r40Ba of the outer shape (that is, the outer circumference) of the second bush main body 40Ba centered on the second reference axis 10Ba is defined as the radius of the second bush main body.

Further, the length L40Ab of the first flange portion 40Ab in the direction along the first reference axis 10Aa is defined as the length in the axial direction of the first flange portion, and the length L40Bb of the second flange portion 40Bb in the direction along the second reference axis 10Ba. Is defined as the axial length of the second flange portion.

Further, the radius r40Ab of the outer shape (that is, the outer circumference) of the first flange portion 40Ab centered on the first reference axis 10Aa is defined as the radius of the first flange portion, and the second flange portion 40Bb centered on the second reference axis 10Ba. The radius r40Bb of the outer shape (that is, the outer circumference) is defined as the radius of the second flange portion.

The first bush main body 40Aa is configured to be able to be accommodated in the first bush main body accommodating portion 33Aa. That is, in the first bush main body 40Aa, the axial length L40Aa of the first bush main body is shorter than the axial length L33Aa of the first bush main body accommodating portion, and the first bush main body radius r40Aa is the first bush main body portion. It has a shape smaller than the accommodating portion radius r33Aa. Further, the second bush main body 40Ba can be accommodated in the second bush main body accommodating portion 33Ba. That is, in the second bush main body 40Ba, the axial length L40ABa of the second bush main body is shorter than the axial length L33Ba of the second bush main body accommodating portion, and the radius r40Ba of the second bush main body is the second bush main body. It has a shape smaller than the accommodating portion radius r33Ba.

That is, the outer diameter of the first bush main body 40Aa (twice the radius r40Aa) is smaller than the inner diameter of the first bush main body accommodating portion 33Aa (twice the radius r33Aa). Further, the outer diameter of the second bush main body 40Ba (twice the radius r40Aa) is smaller than the inner diameter of the second bush main body accommodating portion 33Ba (twice the radius r33Aa).

The first flange portion 40Ab is configured to be accommodating in the first flange portion accommodating portion 33Aa. That is, in the first flange portion 40Ab, the first flange portion axial length L40Ab is shorter than the first flange portion accommodating portion axial length L33Ab, and the first flange portion radius r40Ab is from the first flange portion accommodating portion radius r33Ab. Also has a small shape. Further, in the second flange portion 40Bb, the second flange portion axial length L40Bb is shorter than the second flange portion accommodating portion axial length L33Bb, and the second flange portion radius r40Bb is from the second flange portion accommodating portion radius r33Bb. Also has a small shape.

That is, the outer diameter of the first flange portion 40Ab (twice the radius r40Ab) is smaller than the inner diameter of the first flange portion accommodating portion 33Ab (twice the radius r33Ab). Further, the outer diameter of the second flange portion 40Bb (twice the radius r40Bb) is smaller than the inner diameter of the second flange portion accommodating portion 33Bb (twice the radius r33Bb).

The following configurations are different between the first steering device 1A and the second steering device 1B described above.

In this embodiment, the second flange portion accommodating portion axial length L33Bb is shorter than the first flange portion axial length L40Ab, or the second flange portion accommodating portion radius r33Bb is smaller than the first flange portion radius r40Ab. Has. Further, the axial length L40Ba of the second bush main body is longer than the axial length L33Aa of the first bush main body, or the radius r40Ba of the second bush main body is larger than the radius r33Aa of the first bush main body. It has a shape.

Next, a method for manufacturing the steering devices 1A and 1B according to the present invention will be described.

FIG. 4A is a diagram showing a manufacturing process of the steering device 1A. FIG. 4B is a diagram showing a manufacturing process of the steering device 1B.

The manufacturing method of the steering device 1A of this embodiment includes a first bush assembly step S1 and a first rack bar assembly step S2. The method for manufacturing the steering device 1B includes a second bush assembly step S3 and a second rack bar assembly step S4.

The first bush assembly step S1 is a step of assembling the first bush 40A to the first bush accommodating portion 33A.

The first rack bar assembly step S2 is a step of inserting the first rack bar 10A into the first rack bar accommodating portion 32A while inserting it into the first bush 40A.

The second bush assembling step S3 is a step of assembling the second bush 40B to the second bush accommodating portion 33B.

The second rack bar assembly step S4 is a step of inserting the second rack bar 10b into the second rack bar accommodating portion 33B while inserting the second rack bar 10b into the second bush 40B.

As described above, on the same production line, the steering device 1A is manufactured by the first bush assembly step S1 and the first rack bar assembly step S2, and the second bush assembly step S3 and the second rack bar assembly step. Manufacturing of the steering device 1B by S4 is executed.

In the manufacturing method of the steering devices 1A and 1B of the present embodiment, the manufacturing of the steering device 1A by the first bush assembly step S1 and the first rack bar assembly step S2 and the second bush assembly step on the same production line. Manufacturing of the steering device 1B according to S3 and the second rack bar assembly step S4 is executed. When the steering device 1A of the first specification and the steering device 1B of the second specification are mixed and produced on the same production line, the second bush 40B of the second specification is erroneously assembled to the first rack housing 30A of the first specification. There is a risk that it will end up. On the contrary, there is a possibility that the first bush 40A of the first specification is erroneously assembled to the second rack housing 30B of the second specification.

However, in the manufacturing method of the present embodiment, a morphological feature that enables a combination of both 40A and 33A is provided between the first bush 40A and the first bush accommodating portion 33A that receives the first bush 40A. Between the two bushes 40B and the second bush accommodating portion 33B that receives the second bush 40B, a morphological feature that enables the combination of both 40B and 33B is provided. Thereby, the manufacturing method of this embodiment prevents the second bush 40B from being assembled to the first rack housing 30A, and prevents the first bush 40A from being assembled to the second rack housing 30B.

In this embodiment, when the second bush 40B is to be assembled to the first rack housing 30A, the radius (or outer diameter) centered on the first reference axis 10Aa or the second reference axis 10Ba, or the first reference axis. Since the second bush main body 40Ba cannot be inserted into the first bush main body accommodating portion 33Aa due to the problem of the length along the 10Aa or the second reference axis 10Ba, the second bush 40B is assembled to the first rack housing 30A. Wrong combinations can be detected.

When the first bush 40A is to be assembled to the second rack housing 30B, the radius (or outer diameter) centered on the first reference axis 10Aa or the second reference axis 10Ba, or the first reference axis 10Aa or the first. 2 Since the first flange portion 40Ab cannot be inserted into the second flange portion accommodating portion 33Bb due to the problem of the length in the direction along the reference axis 10Ba, an erroneous combination of assembling the first bush 40A to the second rack housing 30B is detected. can do. As a result, it is possible to suppress the problem that the parts of the first specification and the parts of the second specification are assembled by an erroneous combination between the steering device 1A of the first specification and the steering device 1B of the second specification. can do.

In this case, the first bush 40A may have a shape in which the first flange portion axial length L40Ab is longer than the second flange portion accommodating portion axial length L33Bb. As a result, it is not necessary to provide a radial difference between the first flange portion 40Ab and the second flange portion 40Bb due to the first flange portion radius r40Ab, so that the first flange portion accommodating portion radius r33Ab is suppressed from becoming large. can do. In other words, it is possible to suppress an increase in the depth of the groove of the first flange portion accommodating portion 33Ab, and it is possible to suppress a decrease in the wall thickness of the first rack housing 30A.

FIG. 5 is a diagram showing a state in which the first bush 40A is erroneously assembled to the second rack housing 30B, when the axial length L33Bb of the second flange portion accommodating portion is shorter than the axial length L40Ab of the first flange portion. It is a figure which shows the assembly state of.

In the state of FIG. 5, the first bush 40A is inserted into the second rack housing 30B until the first flange portion 40Ab overlaps with the second flange portion accommodating portion 33Bb in the direction along the second reference axis 10Ba. There is. In this state, since the second flange portion accommodating portion axial length L33Bb is shorter than the first flange portion axial length L40Ab, the first flange portion 40Ab does not fit in the second flange portion accommodating portion 33Bb. Therefore, the minimum inner diameter Di40Ab centered on the second reference axis 10Ba of the first flange portion 40Ab is smaller than the outer diameter Do10B of the second rack bar 10B.

In this embodiment, the first flange portion 40Ab is configured so as not to fit in the second flange portion accommodating portion 33Bb, so that when the first bush 40A is erroneously inserted into the second bush accommodating portion 33B, the first bush 40A Since the minimum inner diameter Di40Ab is smaller than the outer diameter Do10B of the second rack bar 10B, it is possible to detect erroneous assembly of parts when assembling the second rack bar 10B.

The same effect can be obtained by setting the radius r33Bb of the second flange portion accommodating portion to be smaller than the radius r40Ab of the first flange portion.

The second bush 40B may have a shape in which the axial length L40Ba of the second bush main body portion is longer than the axial length L33Aa of the first bush main body portion accommodating portion. As a result, it is not necessary to provide a difference between the first bush main body 40Aa and the second bush main body 40Ba due to the second bush main body radius r40Ba, so that the second bush main body accommodating portion radius r33Ba becomes large. It can be suppressed. In other words, it is possible to suppress an increase in the depth of the groove of the second bush main body accommodating portion 40Ba, and it is possible to suppress a decrease in the wall thickness of the second rack housing 30B.

FIG. 6 is a diagram showing a state in which the second bush 40B is erroneously assembled to the first rack housing 30A, and the second bush main body portion axial length L40Ba is larger than the first bush main body housing portion axial length L33Aa. It is a figure which shows the assembly state in the case of a long time.

In the state of FIG. 6, the second bush 40B is inserted into the first rack housing 30A until the second bush main body 40Ba overlaps with the first bush main body accommodating portion 33Aa in the direction along the first reference axis 10Aa. ing. In this state, the second flange portion 40Bb of the second bush 40B is displaced from the position of the first flange portion accommodating portion 33Ab, so that the second flange portion 40Bb does not fit in the first flange portion accommodating portion 33Ab. Therefore, the minimum inner diameter Di40Ba centered on the first reference axis 10Aa of the second bush main body 40Ba is smaller than the outer diameter Do10A of the first rack bar 10A.

In this embodiment, the second flange portion 40Bb is configured so as not to fit in the first flange portion accommodating portion 33Ab, so that when the third bush 40b is mistakenly inserted into the first bush accommodating portion 33A, the second bush 40B Since the minimum inner diameter Di40Ba is smaller than the outer diameter Do10A of the first rack bar 10A, it is possible to detect erroneous assembly of parts when assembling the first rack bar 10A.

The same effect can be obtained by making the second bush main body radius r40Ba larger than the first bush main body accommodating radius r33Aa.

The first bush 40A of the steering device 1A of the first specification may be provided with a plurality of first O-rings 50. The plurality of first O-rings 50 are provided between the first bush main body accommodating portion 33Aa and the first bush main body 40Aa in the radial direction about the first reference axis 10Aa. In this case, the second bush 40B of the steering device 1B of the second specification includes a plurality of second O-rings 51 having a larger number than the number of the first O-rings 50 provided in the steering device 1A of the first specification. do. The plurality of second O-rings 51 are provided between the second bush main body accommodating portion 33Ba and the second bush main body 40Ba in the radial direction centered on the second reference axis 10Ba.

In the second bush 40B, since the axial length L40Ba of the second bush main body portion is larger than the axial length L40Aa of the first bush main body portion, there is a space for providing a larger number of O-rings 51. Therefore, when the numbers of the O-rings 50 and 51 are different between the steering device 1A of the first specification and the steering device 1B of the second specification, the arrangement of the plurality of second O-rings 51 in the second bush main body 40Ba is arranged. The degree of freedom increases.

FIG. 7 is an external view of the first bush 40A as viewed from the radial direction. FIG. 8 is an external view of the first bush 40A as viewed from the right side of FIG. 7. FIG. 9 is an external view of the first bush 40A as viewed from the left side of FIG. 7.

In this embodiment, the steering device 1A of the first specification includes a plurality of first O-rings 50. Further, the first bush 40A includes a first small diameter portion 40Aa1 provided in the first bush main body portion 40Aa. The first small diameter portion 40Aa1 is provided on the opposite side of the first flange portion 40Ab of the first bush main body portion 40Aa in the direction along the first reference axis 10Aa.
The outer diameter D40Aa1 centered on the first reference axis 10Aa is smaller than the outer diameter D40Aa of the first bush main body. That is, the radius r40Aa1 of the outer diameter of the first small diameter portion 40Aa1 centered on the first reference axis 10Aa is smaller than the radius r40Aa of the first bush main body portion. The plurality of first O-rings 50 are located between the first bush main body accommodating portion 33Aa and the first bush main body 40Aa in the radial direction centered on the first reference axis 10Aa, and are in the direction along the first reference axis 10Aa. Is provided between the first small diameter portion 40Aa1 and the first flange portion 40Ab.

According to this configuration, a portion 40Aa0 in which the first O-ring 50 is provided and a first small-diameter portion 40Aa1 in which the first O-ring 50 is not provided are provided in the first bush main body portion 40Aa. The first small diameter portion 40Aa1 defines the insertion position of the first bush 40A in the direction along the first reference axis 10Aa. In this case, by making the first small diameter portion 40Aa1 smaller in diameter than the portion 40Aa0 provided with the first O ring 50, it is possible to suppress the influence of the first small diameter portion 40Aa1 on the characteristics of the first O ring 50.

Further, as shown in FIGS. 7 to 9, the first bush 40A has a notch 40Ac extending from the first flange 40Ab to the first bush main body 40Aa and a notch provided in the first bush main body 40Aa. A unit 40Ad is provided. The cutout portions 40Ac and 40Ad increase the deformation of the first bush 40A when the first bush 40A is erroneously inserted into the second rack housing 30B. As a result, the first bush 40A easily interferes with the second rack bar 10B, and it becomes easy to find an erroneous assembly of the first bush 40A.

FIG. 10 is an external view of the second bush 40B as viewed from the radial direction. FIG. 11 is an external view of the second bush 40B as viewed from the right side of FIG. FIG. 12 is an external view of the second bush 40B as viewed from the left side of FIG.

Further, in this embodiment, as shown in FIGS. 2 and 3, the steering device 1B of the second specification includes a plurality of second O-rings 51. Further, the second bush 40B includes a second small diameter portion 40Ba1 provided in the second bush main body portion 40Ba. The second small diameter portion 40Ba1 is provided on the opposite side of the second flange portion 40Bb of the second bush main body portion 40Ba in the direction along the second reference axis 10Ba, and is provided outside the second reference axis 10Ba. The radius r40Ba1 of the diameter is smaller than the radius r40Ba of the second bush main body. That is, the outer diameter D40Ba1 of the second small diameter portion 40Ba1 centered on the second reference axis 10Ba is smaller than the outer diameter D40Ba of the second bush main body portion (see FIG. 10). The plurality of second O-rings 51 are located between the second bush main body accommodating portion 33Ba and the second bush main body 40Ba in the radial direction along the second reference axis 10Ba, and are second in the direction along the second reference axis 10Ba. 2 It is provided between the small diameter portion 40Ba1 and the second flange portion 40Bb.

According to this configuration, a portion 40Ba0 in which the second O-ring 51 is provided and a second small-diameter portion 40Ba1 in which the second O-ring 51 is not provided are provided in the second bush main body portion 40Ba. The second small diameter portion 40Ba1 defines the insertion position (axial position) of the second bush 40B in the direction along the second reference axis 10Ba. In this case, by making the second small diameter portion 40Ba1 smaller in diameter than the portion 40Ba0 provided with the second O ring 51, it is possible to prevent the second small diameter portion 40Ba1 from affecting the characteristics of the second O ring 51.

Further, as shown in FIGS. 10 to 12, the second bush 40B has a notch 40Bc extending from the second flange 40Bb to the second bush main body 40Ba and a notch provided in the second bush main body 40Ba. A unit 40Bd is provided. The cutout portions 40Bc and 40Bd increase the deformation of the second bush 40B when the second bush 40B is erroneously inserted into the first rack housing 30A. As a result, the second bush 40B easily interferes with the first rack bar 10A, and it becomes easy to find an erroneous assembly of the second bush 40B.

FIG. 13 is a diagram showing a state in which a second bush having a second small diameter portion 40Ba1 is erroneously assembled to the first rack housing 30A.

In FIG. 13, although the axial length L40Ba of the second bush main body is larger than the axial length L33Aa of the first bush main body accommodating portion, the second small diameter portion 40Ba1 provided in the second bush main body 40Ba is the first. It shows a state of riding on the rack bar accommodating portion 32A. Since the second small diameter portion 40Ba1 is formed to have a small outer diameter, it is expected that the second small diameter portion 40Ba1 can easily ride on the first rack bar accommodating portion 32A.

In this case, the second bush 40B is inserted into the first rack housing 30A until the second small diameter portion 40Ba1 overlaps with the first rack bar accommodating portion 32A in the direction along the first reference axis 10Aa. In this state, the inner diameter Di40Ba1 centered on the first reference axis 10Aa of the second small diameter portion 40Ba1 is smaller than the outer diameter Do10A of the first rack bar 10A.

As a result, it is assumed that the second small diameter portion 40Ba1 is inserted to the point where it overlaps with the first rack bar accommodating portion 32A because the outer diameter D40Ba1 (see FIG. 12) is small. In this case, it may be difficult to detect an erroneous assembly at the axial position of the second bush 40B with respect to the first rack housing 30A. However, in this embodiment, when the second bush 40B is erroneously assembled to the first rack housing 30A, the inner diameter Di40Ba1 of the second small diameter portion 40Ba1 is smaller than the outer diameter Do10A of the first rack bar 10A. It is possible to detect incorrect assembly of parts.

FIG. 14 is a diagram showing a state in which the first bush 40A provided with the first small diameter portion 40Aa1 is assembled to the first rack housing 30A.

The first rack housing 30A includes a first stage portion 35A provided between the first bush main body portion accommodating portion 33Aa and the first rack bar accommodating portion 32A in the direction along the first reference axis 10Aa. The first stage portion 35A includes a first facing surface 35Aa facing the first bush 40A in a direction along the first reference axis 10Aa. The first facing surface 35Aa may have a shape parallel to the cross section perpendicular to the first reference axis 10Aa.

As a result, when the second bush 40B is erroneously inserted into the first rack housing 30A, the end portion of the second bush 40B comes into contact with the first facing surface 35Aa, and the second bush 40B is at the back of the first rack housing 30A. Regulate that it is inserted up to. At this time, since the first facing surface 35Aa is formed perpendicular to the first reference axis 10Aa, the second bush 40B is easily caught on the first stage portion 35A, and the second bush 40B is the first rack housing 30A. It is possible to prevent it from being inserted all the way to the back.

The present invention is not limited to the above-described embodiment, and some configurations can be deleted or other configurations not described can be added.

1A ... 1st steering device, 1B ... 2nd steering device, 10A ... 1st rack bar, 10Aa ... 1st reference axis, 10B ... 2nd rack bar, 10Ba ... 2nd reference axis, 30A ... 1st rack housing, 30B ... 2nd rack housing, 31A ... 1st rack housing main body, 31Aa ... 1st rack housing 1st end, 31Ab ... 1st rack housing 2nd end, 31B ... 2nd rack housing main body, 31Ba ... 2nd Rack housing 1st end, 31Bb ... 2nd rack housing 2nd end, 32A ... 1st rack bar housing, 32B ... 2nd rack bar housing, 33A ... 1st bush housing, 33Aa ... 1st bush body Unit accommodating portion, 33Ab ... 1st flange accommodating portion, 33B ... 2nd bush accommodating portion, 33Ba ... 2nd bush main body accommodating portion, 33Bb ... 2nd flange portion accommodating portion, 40A ... 1st bush, 40Aa ... 1st Bush body, 40Aa1 ... 1st small diameter, 40Ab ... 1st flange, 40B ... 2nd bush, 40Ba ... 2nd bush body, 40Ba1 ... 2nd small diameter, 40Bb ... 2nd flange, 50 ... 1O Ring, 51 ... 2nd O ring, L33Aa ... 1st bush main body accommodating portion axial length, L33Ab ... 1st flange portion accommodating portion axial length, L33Ba ... 2nd bush main body accommodating portion axial length, L33Bb ... Second flange portion housing portion axial length, L40Aa ... First bush main body axial length, L40Ab ... First flange portion axial length, L40Ba ... Second bush main body axial length, r32A ... 1 rack bar accommodating portion radius, r32B ... second rack bar accommodating portion radius, r33Aa ... first bush main body accommodating portion radius, r33Ab ... first flange accommodating portion radius, r33Ba ... second bush main body accommodating portion radius, r33Bb ... radius of the second flange portion accommodating portion, r40Aa ... radius of the first bush main body portion.

Claims (10)

It is a method of manufacturing a steering device.
The steering device includes a steering device of the first specification and a steering device of the second specification.
The steering device of the first specification includes a first rack bar, a first rack housing, and a first bush.
The first rack bar can steer the steering wheel, and the first rack bar can steer the steering wheel.
The first rack housing includes a first rack housing main body portion, a first rack bar accommodating portion, and a first bush accommodating portion.
The first rack housing main body has a tubular shape, and includes a pair of ends, a first end of the first rack housing and a second end of the first rack housing.
The first rack bar accommodating portion is provided inside the first rack housing main body portion and can accommodate the first rack bar.
The first bush accommodating portion includes a first bush main body accommodating portion and a first flange accommodating portion, and the first in a cross section perpendicular to the moving direction of the first rack bar with respect to the first rack housing. The axis passing through the center of the inner circumference of the rack bar accommodating portion and parallel to the moving direction of the first rack bar is set as the first reference axis, and the first rack bar accommodating portion centered on the first reference axis. When the radius is the radius of the first rack bar accommodating part,
The length of the first bush main body accommodating portion in the direction along the first reference axis is the axial length of the first bush main body accommodating portion, and the radius centered on the first reference axis is the first bush main body portion. When the radius of the accommodating portion is taken, it is provided between the first rack bar accommodating portion and the first end portion of the first rack housing in the direction along the first reference axis, and is provided inside the first rack housing main body portion. It is provided and has a shape in which the radius of the first bush main body accommodating portion is larger than the radius of the first rack bar accommodating portion.
The length of the first flange portion accommodating portion in the direction along the first reference axis is the length in the axial direction of the first flange portion accommodating portion, and the radius centered on the first reference axis is the radius of the first flange portion accommodating portion. , It is provided between the first bush main body accommodating portion and the first rack housing first end portion in the direction along the first reference axis, and is provided inside the first rack housing main body portion. The radius of the first flange portion accommodating portion is larger than the radius of the first bush main body accommodating portion.
The first bush includes a first bush main body portion and a first flange portion, can be accommodated in the first bush accommodating portion, has a tubular shape, and has the first rack bar inserted. Can support the first rack bar,
The first bush main body can be accommodated in the first bush main body, and the axial length of the first bush main body, which is the length in the direction along the first reference axis, is the first bush main body. A shape in which the radius of the first bush body, which is shorter than the axial length of the housing and is the radius of the outer shape of the first bush body centered on the first reference axis, is smaller than the radius of the housing of the first bush body. Have and
The first flange portion can be accommodated in the first flange portion accommodating portion, and the axial length of the first flange portion, which is the length in the direction along the first reference axis, is the first flange portion accommodating portion. It has a shape shorter than the axial length, and the radius of the first flange portion, which is the radius of the outer shape of the first flange portion centered on the first reference axis, is smaller than the radius of the first flange portion accommodating portion. ,
The steering device of the second specification includes a second rack bar, a second rack housing, and a second bush.
The second rack bar can steer the steering wheel, and the second rack bar can steer the steering wheel.
The second rack housing includes a second rack housing main body portion, a second rack bar accommodating portion, and a second bush accommodating portion.
The second rack housing main body has a tubular shape, and includes a pair of ends, a first end of the second rack housing and a second end of the second rack housing.
The second rack bar accommodating portion is provided inside the second rack housing main body portion and can accommodate the second rack bar.
The second bush accommodating portion includes a second bush main body accommodating portion and a second flange accommodating portion, and has a cross section perpendicular to the moving direction of the second rack bar with respect to the second rack housing. The axis passing through the center of the inner circumference of the rack bar accommodating portion and parallel to the moving direction of the second rack bar is set as the second reference axis, and the second rack bar accommodating portion centered on the second reference axis. When the radius is the radius of the second rack bar accommodating part,
The length of the second bush main body accommodating portion in the direction along the second reference axis is the axial length of the second bush main body accommodating portion, and the radius centered on the second reference axis is the second bush main body portion. When the radius of the accommodating portion is taken, it is provided between the second rack bar accommodating portion and the first end portion of the second rack housing in the direction of the second reference axis, and is provided inside the second rack housing main body portion. The radius of the second bush main body accommodating portion is larger than the radius of the second rack bar accommodating portion.
The length of the second flange portion accommodating portion in the direction along the second reference axis is the length in the axial direction of the second flange portion accommodating portion, and the radius centered on the second reference axis is the radius of the second flange portion accommodating portion. , It is provided between the second bush main body accommodating portion and the first end portion of the second rack housing in the direction along the second reference axis, and is provided inside the second rack housing main body portion. The radius of the second flange portion accommodating portion is larger than the radius of the second bush main body accommodating portion, and
In the second flange portion accommodating portion, the axial length of the second flange portion accommodating portion is shorter than the axial length of the first flange portion, or the radius of the second flange portion accommodating portion is smaller than the radius of the first flange portion. Also has a small shape,
The second bush includes a second bush main body portion and a second flange portion, can be accommodated in the second bush accommodating portion, has a tubular shape, and has the second rack bar inserted. Can support the second rack bar,
The second bush main body can be accommodated in the second bush main body accommodating portion, and the axial length of the second bush main body, which is the length in the direction along the second reference axis, is the second bush. The radius of the second bush main body, which is shorter than the axial length of the main body accommodating portion and is the radius of the outer shape of the second bush main body centered on the second reference axis, is larger than the radius of the second bush main body accommodating portion. It has a small shape and
In the second bush main body, the axial length of the second bush main body is longer than the axial length of the first bush main body accommodating portion, or the radius of the second bush main body is accommodating the first bush main body portion. It has a shape larger than the radius of the part and
The second flange portion can be accommodated in the second flange portion accommodating portion, and the axial length of the second flange portion, which is the length in the direction along the second reference axis, is the second flange portion accommodating portion. It has a shape that is shorter than the axial length and the radius of the second flange portion, which is the radius of the outer shape of the second flange portion centered on the second reference axis, is smaller than the radius of the second flange portion accommodating portion. ,
The first bush assembling step of assembling the first bush to the first bush accommodating portion, and
The first rack bar assembling step of inserting the first rack bar into the first rack bar accommodating portion while inserting the first rack bar into the first bush.
The second bush assembling step of assembling the second bush to the second bush accommodating portion, and
A second rack bar assembly step of inserting the second rack bar into the second rack bar accommodating portion while inserting the second rack bar into the second bush.
A method of manufacturing a steering device, which comprises. In the method for manufacturing a steering device according to claim 1,
A method for manufacturing a steering device, wherein the first bush has a shape in which the axial length of the first flange portion is longer than the axial length of the second flange portion accommodating portion. In the method for manufacturing a steering device according to claim 1,
A method for manufacturing a steering device, wherein the second bush has a shape in which the axial length of the second bush main body portion is longer than the axial length of the first bush main body portion accommodating portion. In the method for manufacturing a steering device according to claim 3,
The steering device of the first specification includes a plurality of first O-rings, and the steering device has a plurality of first O-rings.
The plurality of first O-rings are provided between the first bush main body accommodating portion and the first bush main body portion in the radial direction about the first reference axis.
The steering device of the second specification includes a plurality of second O-rings provided in a larger number than the number of the first O-rings provided in the steering device of the first specification.
The plurality of second O-rings are provided between the second bush main body accommodating portion and the second bush main body portion in the radial direction about the second reference axis. Manufacturing method of the device. In the method for manufacturing a steering device according to claim 1,
The first bush is the first bush in a state where the first bush is inserted into the second rack housing until the first flange portion overlaps with the second flange portion accommodating portion in the direction of the second reference axis. A method for manufacturing a steering device, wherein the inner diameter of one flange portion centered on the second reference axis has a shape smaller than the outer diameter of the second rack bar 10A. In the method for manufacturing a steering device according to claim 1,
The second bush is in a state in which the second bush is inserted into the first rack housing until the second bush main body overlaps with the first bush main body accommodating portion in the direction along the first reference axis. The method for manufacturing a steering device, wherein the inner diameter of the second bush main body about the first reference axis has a shape smaller than the outer diameter of the first rack bar. In the method for manufacturing a steering device according to claim 1,
The steering device of the first specification includes a plurality of first O-rings, and the steering device has a plurality of first O-rings.
The first bush includes a first small diameter portion provided in the first bush main body portion.
The first small-diameter portion is provided on the opposite side of the first flange portion of the first bush main body portion in the direction of the first reference axis, and has an outer shape centered on the first reference axis. The radius is smaller than the radius of the first bush body,
The plurality of first O-rings are located between the first bush main body accommodating portion and the first bush main body portion in a radial direction centered on the first reference axis line, and are in a direction along the first reference axis line. A method for manufacturing a steering device, which is provided between the first small diameter portion and the first flange portion. In the method for manufacturing a steering device according to claim 1,
The steering device of the second specification includes a plurality of second O-rings.
The second bush includes a second small diameter portion provided in the second bush main body portion.
The second small diameter portion is provided on the opposite side of the second flange portion of the second bush main body portion in the direction along the second reference axis, and is the radius of the outer diameter with respect to the second reference axis. However, it is smaller than the second bush main body,
The plurality of second O-rings are located between the second bush main body accommodating portion and the second bush main body portion in a radial direction about the second reference axis line, and are in a direction along the second reference axis line. A method for manufacturing a steering device, wherein the steering device is provided between the second small diameter portion and the second flange portion. In the method for manufacturing a steering device according to claim 8,
The second small diameter is inserted into the first rack housing until the second small diameter portion overlaps with the first rack bar accommodating portion in the direction along the first reference axis. A method for manufacturing a steering device, characterized in that the inner diameter of the portion about the first reference axis is smaller than the outer diameter of the first rack bar. In the method for manufacturing a steering device according to claim 1,
The first rack housing includes a first stage portion provided between the first bush main body accommodating portion and the first rack bar accommodating portion in a direction along the first reference axis.
The first stage portion includes a first facing surface facing the first bush in a direction along the first reference axis.
A method for manufacturing a steering device, wherein the first facing surface has a shape parallel to a cross section perpendicular to the first reference axis.

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