JP7578064B2 - Steering gear - Google Patents

Description

The present invention relates to a steering device that connects an operating member, such as a steering wheel, to steered wheels.

The steering device has a column shaft to which an operating member is connected, and multiple shafts connected to the column shaft via universal joints, and the rotation of the shafts around their axes is converted into linear motion by a rack and pinion mechanism to turn the steered wheels.

The universal joint is attached by tightening a fastening member such as a bolt into the fitting hole of the yoke into which the column shaft is inserted. Patent Document 1 describes an enclosing member that encloses the part of the yoke that contains the fastening member to prevent the fastening member from falling off the yoke.

JP 2015-127175 A

However, the steering device disclosed in Patent Document 1 has the problem that the surrounding member gets in the way when attaching the universal joint to the column shaft, reducing workability.

The present invention was developed in consideration of the above problems, and aims to provide a steering device that can ensure high workability when assembling a universal joint to a steering device, while preventing fastening members such as bolts from falling off the yoke when the steering device is in use.

To achieve the above object, the steering device of the present invention comprises a first shaft having an operating member attached to one end thereof, a universal joint attached by tightening a fastening member to a fitting portion into which the other end of the first shaft is inserted, a cylindrical cover member that surrounds the fitting portion at a position away from the fitting portion and has an insertion hole through which the fastening member attached to the fitting portion can pass at a position that can face a fastening hole through which the fastening member is pierced, and a lid member that closes the insertion hole.

According to the present invention, the cover member can prevent the fastening member from falling off the yoke of the universal joint, preventing steering failure. In addition, the fastening member can be fastened through the insertion hole with the cover member attached in a specified position, preventing the cover member from reducing the ease of assembly of the universal joint.

1 is a perspective view showing an external appearance of a steering device according to an embodiment. FIG. 2 is a perspective view showing the steering device according to the embodiment with a bracket removed. 1 is a perspective view showing the vicinity of the universal joint with a cover member 130 in a see-through state. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3.

Below, an embodiment of the steering device according to the present invention will be described with reference to the drawings. Note that the following embodiment is presented as an example to explain the present invention, and is not intended to limit the present invention. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical expressions, the contents of each step in the method, and the order of each step shown in the following embodiment are merely examples, and may include contents not described below. In addition, while geometric expressions such as parallel and orthogonal may be used, these expressions do not indicate mathematical strictness, and include substantially acceptable errors, deviations, and the like. In addition, expressions such as simultaneous and identical also include substantially acceptable ranges.

The drawings are schematic diagrams in which emphasis, omissions, or proportions have been appropriately adjusted in order to explain the present invention, and may differ from the actual shapes, positional relationships, and proportions.

In addition, multiple inventions may be collectively described below as a single embodiment. Some of the content described below is also described as an optional component of the present invention.

Figure 1 is a perspective view showing the appearance of a steering device according to an embodiment. Figure 2 is a perspective view showing the steering device according to an embodiment with the bracket removed. Figure 3 is a perspective view showing the vicinity of a universal joint in a see-through state of a cover member 130. The steering device 100 is a device that rotatably holds an operating member (not shown) such as a steering wheel operated by a driver and can turn steered wheels (not shown) based on the operation of the operating member, and is equipped with a first shaft 111, a universal joint 120, a cover member 130, and a lid member 140. In the case of this embodiment, the steering device 100 is equipped with a housing 150 and a bracket 160. In addition to the above configuration, the steering device 100 may be equipped with a shaft member other than the first shaft 111 and a steering mechanism such as a rack and pinion mechanism, but illustration and description of these are omitted.

The first shaft 111 is a rod-shaped member known as a column shaft or the like, and has an operating member such as a steering wheel that is operated by the driver attached to its tip. The first shaft 111 is rotatably attached to the vehicle body via a bracket 160 and a housing 150, and transmits the steering angle of the operating member to a steering mechanism such as a rack and pinion. The first shaft 111 may be held by a cylindrical member known as an inner tube or the like, and may have a structure such as a spline fit that expands and contracts as the inner tube appears and disappears from the vehicle body, while maintaining the transmission of the steering angle.

Figure 4 is a cross-sectional view taken along line A-A in Figure 3. The universal joint 120 is a joint that transmits rotation around the axis of two members, the first shaft 111 and the second shaft 112, and can freely change the angle between the two members. In this embodiment, the universal joint 120 is a so-called Cardan joint, and includes a first yoke 121, a second yoke 122, and a cross shaft body 129.

The first yoke 121 has a fitting portion 123 into which the other end of the first shaft 111 is inserted. The first shaft 111 and the fitting portion 123 may have a structure to prevent slippage in the rotational direction, such as serration fitting. The fitting portion 123 has a fastening portion 125 that forms a slit 124 that communicates with the hole into which the first shaft 111 is inserted, and the fastening portion 125 has a fastening hole 126 in a direction perpendicular to the slit 124. The fitting portion 123 can fasten the inserted first shaft 111 by fastening the fastening portion 125 in a direction narrowing the interval of the slit 124 with a fastening member 139 inserted into the fastening hole 126. In the case of this embodiment, the fastening member 139 is a bolt, and one of the fastening holes 126 sandwiching the slit 124 is provided with a female thread into which the fastening member 139 is screwed, and the other is not provided with a female thread. This allows the fastening member 139 to be rotated around its axis relative to the first yoke 121 and screwed in, thereby fastening and fixing the end of the first shaft 111 inserted into the fitting portion 123.

The second yoke 122 is a member that rotatably holds the cross shaft body 129 that is rotatably attached to the first yoke 121, and is fitted with the second shaft 112 to which the rotation around the axis of the first shaft 111 is transmitted. In the present embodiment, the second shaft 112 is a rod-shaped member also known as an intermediate shaft, and is connected to the second yoke 122 by welding. The second shaft 112 has a spline fitting structure and can expand and contract in the axial direction.

The cover member 130 is a cylindrical member that surrounds the fitting portion 123 of the first yoke 121 at a predetermined distance from the fitting portion 123 and prevents the fastening member 139 from falling off the fitting portion 123. In the axial direction of the fastening member 139, the distance from the tip of the head portion of the fastening member 139 to the cover member 130 is set to be shorter than the entire length of the fastening member 139. In this embodiment, the cover member 130 is cylindrical, and is positioned so that the distance from the tip of the head portion of the fastening member 139 to the cover member 130 is constant even when the universal joint 120 rotates.

The cover member 130 has an insertion hole 131 of a diameter that allows the head of the fastening member 139 to pass through, at a position that can face the fastening hole 126 through which the fastening member 139 provided in the fitting portion 123 is inserted. The fastening hole 126 provided in the fastened portion 125 of the universal joint 120 extends in a direction perpendicular to the rotation axis at a position eccentric to the rotation axis of the first shaft 111, and the insertion hole 131 is arranged so that the tube axis of the fastening hole 126 and the tube axis of the insertion hole 131 coincide or nearly coincide at a predetermined rotation position of the universal joint 120. Here, nearly coincidence means that a tool such as a hexagonal wrench or box wrench inserted into the insertion hole 131 can engage with the head of the fastening member 139.

In this embodiment, the cover member 130 has a tubular protrusion 132 that protrudes outward from the periphery of the insertion hole 131 in the insertion direction of the fastening member 139 (Z-axis direction in the figure). The protrusion 132 has an end surface 133 at its tip that extends in a plane perpendicular to the insertion direction of the fastening member 139 (XY plane in the figure). By providing the cylindrical cover member 130 with the protrusion 132 that has the end surface 133, it becomes possible to easily form the insertion hole 131 from the end surface 133 using a drill or the like even in a position that is eccentric to the tube axis of the cover member 130.

The cover member 130 is fixed to a cylindrical housing 150 that rotatably holds the first shaft 111. This prevents the cover member 130 from rotating together with the universal joint 120, and prevents the cover member 130 from loosening over time due to rotation, making it impossible to prevent the fastening member 139 from falling off.

In this embodiment, the cover member 130 is fixed by screws via fixing parts 134 that protrude radially outward on both sides from the cylindrical main body. The cover member 130 is attached to the housing 150 so that the protruding direction of the fixing parts 134 is approximately 40 degrees with respect to the tube axis of the insertion hole 131. This makes it possible to fasten and fix the cover member 130 to the housing 150 even when the bracket 160 is attached to the housing 150.

The housing 150 is not particularly limited as long as it is attached to the vehicle body and can hold the first shaft 111 in an inserted state rotatably around its axis. For example, the housing 150 may be an outer tube (outer jacket) that slidably holds an inner tube that holds the first shaft 111 in an inserted state. In the case of this embodiment, the housing 150 is a housing 150 of a coaxial motor that imparts torque to the first shaft 111. The housing 150 of the coaxial motor is attached to a pair of plate-shaped brackets 160 that are arranged opposite each other with the housing 150 in between, and the first shaft is positioned at a predetermined position relative to the vehicle body via the brackets 160.

In this embodiment, the housing 150 is attached to the bracket 160 via the mounting member 170 so that it can swing and reciprocate. The swing position and reciprocating position of the housing 150 relative to the bracket 160 can be fixed by the driver operating a lever or the like. This makes it possible to change the vertical and retractable positions of the operating member attached to the tip of the first shaft 111.

The cover member 130 is fixed to the housing 150 so that the tube axis of the protruding portion 132 does not intersect with any of the brackets 160. Specifically, the cover member 130 is attached so that the protruding portion 132 is on the opposite side of the mounting member 170 with respect to the universal joint 120. This makes it possible to insert the fastening member 139 into the insertion hole 131 and fasten the fastened portion 125 of the universal joint 120 with the fastening member 139 even when the cover member 130 is attached to the housing 150.

The lid member 140 is a member that blocks the insertion hole 131 provided in the cover member 130. This prevents the fastening member 139 from falling off the insertion hole 131. The method of attaching the lid member 140 to the insertion hole 131 is not particularly limited, and may be press-fitting or bonding. In the case of this embodiment, a female thread is provided on the inner surface of the protrusion 132 that forms the insertion hole 131, and the lid member 140 having a male thread is screwed onto the protrusion 132 to attach the lid member 140. This allows the relatively long protrusion 132 in the tube axis direction to be screwed onto the lid member 140, making it possible to improve the attachment strength. The lid member 140 is set to a length that does not protrude inside the cover member 130 when attached to the insertion hole 131. This prevents the lid member 140 from interfering with the first yoke 121 and the fastening member 139.

According to the steering device 100 of the embodiment, the cylindrical cover member 130 is attached around the fastened portion 125 of the universal joint 120, so that even if the fastening member 139 loosens, it can be prevented from falling off the fastened portion 125. This prevents the universal joint 120 from transmitting rotation from the first shaft 111 to the second shaft, and prevents steering from becoming impossible.

In addition, by providing the cover member 130 with an insertion hole 131 for fastening the fastening member 139, the fastening member 139 can be rotated with a tool to fasten the universal joint 120 and the first shaft 111 even after the cover member 130 is fixed to the housing 150. This allows the universal joint 120 attached to the second shaft 112 to be fixed to the first shaft 111, and the first shaft 111 and the second shaft 112 can be connected via the universal joint 120 after a part such as a dust boot is attached near the universal joint 120 of the second shaft 112.

The present invention is not limited to the above-described embodiment. For example, the components described in this specification may be combined in any way, or some of the components may be removed to create another embodiment of the present invention. The present invention also includes modifications that are made to the above-described embodiment by those skilled in the art without departing from the spirit of the present invention, i.e., the meaning of the words in the claims.

For example, although the cover member 130 has been illustrated as a cylindrical member, the peripheral wall of the cover member 130 may have a hollowed-out structure such as a mesh. If the mesh does not allow the fastening member 139 to pass through, the weight of the cover member 130 can be reduced.

The material of the cover member 130 is not particularly limited and may be metal, resin, etc.

In addition, the universal joint 120 is not limited to a Cardan joint, but may be another type of universal joint, such as a constant velocity joint.

In addition, the housing 150 may be not only the housing of a coaxial motor, but also the housing of a reducer that transmits the torque of the motor to the first shaft 111.

The present invention can be used in a steering device that holds an operating member for steering a moving object such as a vehicle.

100...Steering device, 111...First shaft, 112...Second shaft, 120...Universal joint, 121...First yoke, 122...Second yoke, 123...Fitting part, 124...Slit, 125...Tightened part, 126...Tightening hole, 129...Cross shaft body, 130...Cover member, 131...Through hole, 132...Protruding part, 133...End surface part, 134...Fixed part, 139...Tightening member, 140...Cover member, 150...Housing, 160...Bracket, 170...Mounting member

Claims (5)

A first shaft having an operating member attached to one end thereof;
a universal joint that is attached by tightening a fitting portion into which the other end of the first shaft is inserted using a tightening member;
a cylindrical cover member that surrounds the fitting portion at a position away from the fitting portion and has an insertion hole through which the fastening member attached to the fitting portion can pass at a position that can face a fastening hole through which the fastening member is pierced;
A cover member that closes the insertion hole;
A steering device comprising: a housing that rotatably holds the first shaft in an inserted state;
The steering device according to claim 1 , wherein the cover member is fixed to the housing. The housing includes:
The steering device according to claim 2 , which is a housing for a coaxial motor that imparts torque to the first shaft. The cover member is
a tubular protrusion protruding outward from a peripheral portion of the insertion hole in the insertion direction of the fastening member,
The protrusion is
The steering device according to claim 1 , wherein a tip of the protrusion is provided with an end face portion that extends in a plane perpendicular to the insertion direction. a pair of plate-shaped brackets for disposing the first shaft at a predetermined position relative to a vehicle body,
The brackets are disposed on both sides of the first shaft so as to face each other,
The cover member is
5. The steering apparatus according to claim 4, which relies on claim 2, wherein the protrusion is fixed to the housing in such a manner that the tube axis of the protrusion does not intersect with any of the brackets.

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