JP2007120220A - Upper part steering device of wheel-type construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an upper part steering device of a wheel-type construction machine by which a foot space in an operator's cabin and a field of front vision is enlarged in a simple structure. <P>SOLUTION: The upper part steering device 30 of a hydraulic excavator that is a wheel type construction machine comprises a steering column 42, provided with a tilt mechanism at the lower part, a decorating cover 60 surrounding the steering column 42, and a cornice-like dustproof boot 64 which is provided between a lower end of the decorating cover 60 and the steering column 42 and in a manner of being tapered downward. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheel-type construction machine, and more particularly to an upper steering apparatus for steering the wheel-type construction machine.

This type of wheel-type construction machine includes an upper swivel on the upper side of the wheel-type lower traveling body, and a work device for construction work on the upper swivel, the operation of the work device, and the lower traveling body. A driver's cab for self-propelled operation is provided.
Since the lower traveling body is a wheel type, an upper steering device having a steering handle is arranged in the driver's cab, and this upper steering device has a steering column that connects the steering handle and the lower traveling body side steering unit. In addition, a tilt mechanism is incorporated in the steering column (see, for example, FIG. 3 of Patent Document 1).

The tilt mechanism described above allows the steering column to tilt in the anteroposterior direction of the cab, so that the position of the steering handle can be changed in the anteroposterior direction, so that the operator can change the steering handle to a position suitable for its physique during driving operation. The steering handle can be positioned at a retracted position that does not interfere with getting on and off when the user gets on and off the cab.
JP 2003-27524 A

In the case of the above-described upper steering device of Patent Document 1, since the steering column can tilt, it is necessary to prevent dust from the tilt mechanism. For this reason, the tilt mechanism is covered with a decorative cover that forms an instrument panel together with the steering column.
However, since the decorative cover permits tilting of the steering column, the structure thereof becomes complicated, which not only increases the number of parts, but also requires a lot of labor for the assembly.

Moreover, since the decorative cover of the upper steering device of Patent Document 1 extends to the floor of the driver's cab, the foot space in front of the driver's seat and the forward field of view through the front window are narrowed. It has an adverse effect.
The present invention has been made on the basis of the above-described circumstances, and the object is to have a simple configuration capable of reducing the number of parts, and the upper part of the wheel type construction machine that can greatly improve the operability of the working device. The object is to provide a steering device.

  In order to achieve the above object, an upper steering device of a wheel type construction machine according to the present invention is erected from a floor of a driver's cab on the upper swivel, has a steering handle at an upper end, and is predetermined from the floor. A steering column having a variable mechanism that varies the position of the steering handle at a height of the steering wheel, a decorative cover that surrounds the steering column from a position below the steering handle across the variable mechanism, and a lower end of the decorative cover. A downward tapered shape extending over the steering column is provided, and an elastically deformable dustproof boot covering the variable mechanism is provided.

According to the upper steering device of the first aspect, when the steering column is moved through the variable mechanism with the decorative cover in order to change the position of the steering handle, the dustproof boot allows the movement of the decorative cover by its elastic deformation. To do.
Further, since the dustproof boot has a shape that tapers downward, a space for enclosing the steering column is ensured between the floor of the cab and the dustproof boot.

  Specifically, the steering column includes a steering shaft having a steering wheel, an outer tube surrounding the steering shaft, and an inner joint and an outer joint that are inserted into the steering shaft and the outer tube, respectively, and constitute the variable mechanism. The dustproof boot has an upper end connected to the lower end of the decorative cover and a lower end connected to the outer joint of the outer tube (claim 2).

Further, the cab floor may include a floor mat, in which case the floor mat has a raised portion surrounding the steering column below the dustproof boot (Claim 3), and the raised floor. It is desirable that the upper end of the part sandwiches the lower end of the dustproof boot between the steering column (claim 4).
The raised portion of the floor mat functions as a dust-proof member for the lower part of the steering column by covering the lower part of the steering column exposed from the dust-proof boot and having the lower end of the dust-proof boot as a seal member.

  The variable mechanism described above is a tilt mechanism that tilts the steering column in the front-rear direction of the cab (Claim 5), or a telescopic mechanism that expands and contracts the steering column up and down.

Since the upper steering device of the wheel type construction machine according to any one of claims 1 to 5 includes a dustproof boot between the decorative cover and the steering column, the decorative cover can be used together with the steering column without complicating the configuration of the decorative cover. It can be moved, and the number of parts can be reduced and the assembly can be simplified.
In addition, since the dustproof boots are tapered downward, a space is secured around the steering column between the cab floor and the dustproof boots. This space is not only for the operator's feet, but also through the front window. It greatly contributes to the expansion of the forward field of view and greatly improves the working environment for the operator.

  Furthermore, if the floor mat laid on the floor of the cab has a raised portion surrounding the lower part of the steering column, this raised portion can also be used as a dustproof member.

FIG. 1 shows a wheeled hydraulic excavator as a wheeled construction machine.
The hydraulic excavator includes an upper swivel 4 that can swivel on a wheel-type lower traveling body 2, and a work device 6 and a cab 8 that perform construction work are disposed on the front of the upper swivel 4, respectively. .
The working device 6 includes a boom 10 whose base end is pivotally supported on the upper swivel base 4 side, and an excavation bucket 14 rotatably attached to the distal end of the boom 10 via an arm 12. 10, the arm 12 and the excavation bucket 14 are rotated by the expansion and contraction of the boom cylinder 16, the arm cylinder 18 and the bucket cylinder 20, respectively.

  The driver's cab 8 is used to operate the lower traveling body 2 and the work device 6 in operation, and a counterweight 22 for the work device 6 is disposed on the upper swivel 4 at the rear thereof. A building 24 containing an engine (not shown) is arranged between the cab 8 and the counterweight 22. The engine in the building 24 drives a main hydraulic pump (not shown) and the like, and pressure oil is supplied from the main hydraulic pump to the traveling hydraulic motor (not shown) of the lower traveling body 2 and the above-described cylinders of the work device 6. The

  As described above, since the lower traveling body 2 is a wheel type, an upper steering device 30 having a steering handle 28 is disposed in front of the driver's seat 26 in the cab 8 as shown in FIG. On the left and right sides of the seat 26, consoles 34 each having an operation lever 32 are arranged. Further, on the floor of the cab 8, a traveling pedal 36, a brake pedal 38, a spare pedal 40, and the like are arranged around the upper steering device 30.

  The upper steering device 30 is used to steer the lower traveling body 2 by rotating the steering handle 28, and the traveling pedal 36 and the brake pedal 38 are used to move the lower traveling body 2 forward and backward and brake by stepping on the pedal. The The left and right control levers 32 control the operation of the actuator 6, and the spare pedal 40 is used to control the operation of the attachment when a part of the actuator 6 is replaced with the attachment.

As shown in FIG. 3, the upper steering device 30 includes a steering column 42, and the steering column 42 is a floor made of a synthetic resin that is laid on the floor 44 of the cab 8, that is, the floor 44 in front of the driver seat 26. It is erected from the mat 46.
Specifically, the steering column 42 has a steering shaft 48 at the center thereof, and a steering handle 28 is attached to the upper end of the steering shaft 48. The steering shaft 48 penetrates the floor 44 and the floor mat 46 in the vertical direction, and the lower end thereof is connected to the steering actuator on the lower traveling body 2 side. The steering actuator converts the rotation of the steering shaft 48 into a reciprocating motion of left and right tie rods (not shown), and steers the left and right steering wheels (front wheels) of the lower traveling body 2 via these tie rods.

A universal joint 50 as an inner joint is inserted in the steering shaft 48, and the universal joint 50 is positioned at a predetermined height position from the floor mat 46. More specifically, the steering shaft 48 has a divided structure including an upper shaft portion 48 _U and a lower shaft portion 48 _L, and the upper and lower shaft portions 48 _U and 48 _L are connected to each other via a universal joint 50. Yes.

When the upper shaft portion 48 _U with the rotational operation of the steering wheel 28 is rotated, the universal joint 50 transmits the rotation of the upper shaft portion 48 _U to the lower shaft portion 48 _L. The universal joint 50 allows tilting of the upper shaft portion 48 _U with respect to the lower shaft portion 48 _L, in the present embodiment, the upper shaft portion 48 _U cab about a tilt axis A of the universal joint 50 The distance between the tilt axis A and the floor mat 46 is indicated by the reference symbol H in FIG.

Further, the steering column 42 includes an outer tube 52, and the outer tube 52 extends upward from a base plate 54 fixed to the floor 44 of the cab 8, and surrounds the steering shaft 48.
The outer tube 52 has a rotary joint 56 as an outer joint at a height position corresponding to the universal joint 50. That is, similarly to the outer tube 52 is also the steering shaft 48, without a split structure composed of an upper tube portion 52 _U and a lower tube portion 52 _L, pivot joint 56 to the upper and lower tube portions ₅₂ U, 52 _L to each other The universal joint 50 of the steering shaft 48 is accommodated therein.

The rotary joint 56 is configured by fitting upper and lower U-shaped members 56 _U and 56 _L to each other and connecting these U-shaped members 56 _U and 56 _L by a pair of pins 58. These pins 58 are respectively positioned on the tilting axis A of the universal joint 50, and the upper U-shaped member 56 _U (upper tube portion 52 _U ) is opposed to the lower U-shaped member 56 _L (lower tube portion 52 _L ). The pin 58 (tilt axis A) of the rotary joint 56 can be turned around. That is, the universal joint 50 and the rotary joint 56 constitute a tilt mechanism that tilts the steering column 42 about the tilt axis A.

Further, the above-described steering column 42 is surrounded by a rectangular tube-shaped decorative cover 60 at the top. The decorative cover 60 corresponds to an instrument panel of a passenger car, the lower end of the decorative cover 60 is positioned above the tilt axis A, and the steering shaft 48 protrudes upward from the upper wall of the decorative cover 60.
A retainer ring 62 is disposed in the decorative cover 60, and the retainer ring 62 passes through the upper tube 52 _U of the outer tube 52. Accordingly, the decorative cover 60 is supported by the steering column 42 via the retainer ring 62 and rotates in conjunction with the tilting of the steering column 42.

A dustproof boot 64 is provided between the lower end of the decorative cover 60 and the steering column 42, specifically, a U-shaped member 56 _L on the lower side of the rotary joint 56. The dustproof boot 64 is provided with the rotary joint 56. The universal joint 50 is covered, and the joints 50 and 56 are protected from dirt, mud, etc. brought into the cab 8 by the operator.
As is apparent from FIG. 3, the dustproof boot 64 is made of an elastically deformable material such as rubber and has a tapered bellows shape downward, and the upper end is fixed to the lower end of the decorative cover 60 via a plurality of clips 66. is, and its lower end is also at lower than the tilt axis a, is fixed via a plurality of clips 68 on the lower side of the U-shaped member 56 _L of the rotating joint 56. The dustproof boot 64 described above allows tilting of the decorative cover 60 interlocked with the steering column 42 by expansion and contraction while maintaining its original dustproof function.

Further, as is apparent from FIG. 3, a rising portion 70 is integrally formed on the floor mat 46 so as to surround the lower portion of the steering column 42. The rising portion 70 has an upper end and a U-shaped member 56 on the lower side. pinching the bottom edge of the dust-proof boot 64 between the _{L, the} steering column 42 to dustproof boot 64 as a sealing member, i.e., surrounds the lower tube portion 52 _L airtight. Accordingly, the rising portion 70 is only slightly larger in cross section than the bottom cross section of the dustproof boot 64, and below the decorative cover 60 is an outer extension line OL of the decorative cover 60 indicated by a two-dot chain line. A space S is secured between the dustproof boot 64 and the rising portion 70 of the floor mat 46.

Since the tilting of the decorative cover 60 interlocked with the steering column 42 is permitted not by the decorative cover 60 itself but by the dustproof boot 64, the configuration of the decorative cover 60 becomes simple. Therefore, the number of parts of the entire upper steering device 30 is reduced, and the assembly thereof is also facilitated.
Further, the presence of the space S described above greatly enlarges the operator's foot space, as is apparent from FIG. Expanding. As a result, even when the excavator is in a work state as shown in FIG. 1, the operator can visually recognize the excavation bucket 14 from the cab 8 and can easily perform the excavation work, thereby greatly improving workability. The

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the steering column 42 is not limited to tilting back and forth of the cab 8 but may extend and contract in the vertical direction. In this case, as shown in FIG. 5, the steering column 42 includes a telescopic mechanism 72, and the telescopic mechanism 72 is realized by a sliding joint inserted into the steering shaft 48 and the outer tube 52. Incidentally, the sliding joint of the steering shaft 48 is spline-type for example, shall for transmitting the rotation of the upper shaft portion 48 _U to the lower shaft portion 48 _L.

  Finally, it goes without saying that the present invention is applicable not only to wheeled hydraulic excavators but also to various wheeled construction machines.

It is the side view which showed the wheel type hydraulic excavator. It is the schematic plan view which showed the driver's cab of FIG. FIG. 3 is a cross-sectional view showing a part of the upper steering device of FIG. 2. FIG. 2 is a perspective view showing a positional relationship between a space secured at a lower portion of the upper steering device of FIG. 1 and a front window. It is the schematic which showed the upper steering apparatus of the modification.

Explanation of symbols

2 Lower traveling body 4 Upper swivel base 6 Working device 8 Driver's cab 28 Steering handle 30 Upper steering device 42 Steering column 44 Floor 46 Floor mat 48 Steering shaft 50 Universal joint 52 Outer tube 56 Rotating joint 60 Cosmetic cover 64 Dustproof boot 70 Standing Raised part

Claims (5)

An upper swivel capable of swiveling is disposed on the upper side of the wheel-type lower traveling body, and a work device and a cab for construction are provided on the upper swivel. In the wheel-type construction machine that performs work operation from the driver's cab,
A steering column that is erected from the floor of the driver's cab, has a steering handle at the upper end, and includes a variable mechanism that changes the position of the steering handle to a predetermined height position from the floor;
A decorative cover surrounding the steering column from the position below the steering handle across the variable mechanism;
An upper steering device for a wheel type construction machine, characterized in that it comprises a downwardly tapered shape extending from the lower end of the decorative cover to the steering column and elastically deformable dustproof boots covering the variable mechanism. The steering column is
A steering shaft comprising the steering wheel;
An outer tube surrounding the steering shaft;
Including an inner joint and an outer joint that are inserted in each of the steering shaft and the outer tube and constitute the variable mechanism,
The upper steering device for a wheel type construction machine according to claim 1, wherein the dustproof boot has an upper end connected to a lower end of the decorative cover and a lower end connected to the outer joint of the outer tube. . The upper part of the wheel type construction machine according to claim 1 or 2, wherein the floor includes a floor mat, and the floor mat has a rising portion surrounding the steering column below the dustproof boot. Steering device. 4. The upper steering device for a wheel type construction machine according to claim 3, wherein the rising portion of the floor mat has an upper end sandwiching a lower end of the dustproof boot with the steering column. 5. The upper steering device for a wheel type construction machine according to claim 1, wherein the variable mechanism is a tilt mechanism that tilts the steering column in a front-rear direction of the cab.

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