JPH0645416Y2 - Crane car steering system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a steering device for a mobile crane.

(Prior Art) As a crane vehicle, a truck crane vehicle is known which is developed from a crane mounting on a truck base. Many of these truck cranes have a cab (carrier house) for general travel and a crane house for crane work independently, have the same traveling performance as a general truck, and can be moved over a long distance. . In addition, since there are few restrictions on the crane body, it is possible to provide a large suspension capacity for the tonnage. However, truck cranes are difficult to enter narrow alleys, have poor mobility on rough terrain, and have an approach angle or departure angle because of the large size of the vehicle and restrictions on the steering system. There is a problem that it is inferior in maneuverability on site, such as it cannot be taken large.

On the other hand, a rough terrain mobile crane is known that emphasizes mobility on site. This rough terrain mobile crane uses the same crane house to operate the vehicle during traveling and the crane during crane work. It has all-wheel drive function (4WD) and all-wheel steering function (4WS), so it can be used on-site. It has excellent properties. However, due to the large diameter single tire, high ground clearance, and short wheelbase, the running performance on the general road is poor, and because the crane house is driven when driving on the general road, the boom of the crane obstructs visibility.
There is a problem of poor lateral visibility.

Therefore, it is an all-terrain crane vehicle that combines the mobility of a rough terrain crane vehicle and the running performance of a truck crane vehicle, can be operated in both a carrier house and a crane house, and has a hydraulic suspension function, all-wheel steering function, etc. Has been requested. This all-terrain mobile crane is provided with a steering device in each of the two houses so that it can be operated and controlled in both the carrier house and the crane house. Is transmitted to the steering gearbox installed in the vehicle, and the pitman arm connected to the output shaft of this gearbox converts the rotational motion of the output shaft into swing motion, and then this swing motion is connected to the tip of the pitman arm. It is transmitted to a wheel connected to the front axle via a complicated link mechanism (steering force transmission mechanism) such as a drag link to steer the wheel. Further, the all-terrain mobile crane is provided with an outrigger fixedly mounted on the lower surface of the chassis frame between the steering wheel and the front axle. Then, a cross member is fixed between the side members of the chassis frame so as to be bridged, and further,
Since the engine etc. are mounted between the side members,
The link mechanism such as the drag link described above is routed from the gear box to the wheel side through the lower side of the outrigger box.

(Problems to be Solved by the Invention) In the above-mentioned conventional method, the gear box is projected below the carrier house, and the link mechanism such as a drag link is arranged below the outrigger, so that the pitman arm moves vertically. When swinging, the tip of the pitman arm is swung further down below the gearbox, so a part of the link mechanism of the steering device, which is an important safety component during steering, will largely overhang below the outrigger or below the carrier house. , This link mechanism imposes restrictions on the approach angle and departure angle, and there is a problem that these values cannot be set to large values.

Further, since the drag link mechanism is routed from the gearbox to the wheel side through the lower part of the outrigger box, there is a problem that the number of links increases and the link mechanism becomes more complicated.

The present invention has been made in order to solve such a problem, and a large steering angle can be obtained without using a complicated link mechanism, and further, an approach angle and a departure angle can be adversely affected. Aim to provide a steering system for mobile cranes that does not.

(Means for Solving the Problems) According to the present invention in order to achieve the above object, the steering force of the steering wheel of a crane vehicle in which an outrigger box is attached to a chassis frame between a steering wheel and a front axle is provided. , Transmitted to a wheel connected to the front axle via a steering force transmission mechanism,
In a steering device for a crane vehicle that steers the wheels, a spacer is interposed between the outrigger box and the chassis frame, and the steering force transmission mechanism is passed between the outrigger box and the chassis frame. A steering system is provided.

(Operation) Since the spacer is interposed between the outrigger box and the chassis frame and the steering force transmission mechanism is passed between the outrigger box and the chassis frame, the steering force transmission mechanism does not project below the outriggers.

(Embodiment) An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the appearance of an all-terrain mobile crane. The all-terrain mobile crane 1 has a work frame (main frame) 10 extending over substantially the entire length of a vehicle, and a crane 2 mounted on the main frame 10 via a turntable 11. The front side of the front frame 9 extends forward from the front end of the carrier house 3
However, the turntable 11 is provided with crane houses 4 that rotate together with the crane 2, and the operation of the crane vehicle 1 is possible in each of the houses 3 and 4, as will be described later.

When suspending the crane 2, the front outriggers 5 and the rear outriggers 6 attached to the front and rear ends of the main frame 10 are extended laterally to the main frame.
10 is fixed and hanging work is performed. Then, between the outriggers 5 and 6, large single tires 7 and 8 are attached adjacent to the outriggers 5 and 6. A front axle 14 to which the front wheels 7 are attached and a rear axle 16 to which the rear wheels 8 are attached are suspended on the main frame 10 via taper leaf springs 17 and 18, respectively, to provide a highly rigid stabilizer.
Rolling is suppressed by 24 and 26.

The front axle 14 and the rear axle 16 are connected to the side member 10a side wall of the main frame 10 by a pair of left and right hydraulic singles 20 and 22, respectively. This hydraulic cylinder 2
0 and 22 have functions such as a shock absorber function, an anti-nose dive function during braking and turning, and an on-tire function during low-speed suspension.

The output of the engine 30 mounted behind the carrier house 3 and between the side members 10a of the main frame 10 is transmitted to the rear wheels 8 via the transmission 32, the rear side propeller shaft 34, and the final transmission 35. At the same time, by engaging a dog clutch (not shown) incorporated in the transmission 32, it is also transmitted to the front wheels 7 via the dog clutch, the front side propeller shaft 36, and the front side final transmission 38. It The transmission 32 can be changed by selecting a shift position of a shift lever (not shown) provided in the carrier house 3 and the crane house 4,
The carrier house 3 which is driven when traveling on a general road can be switched to 5 steps forward and 3 steps backward, and the crane house 4 can be switched to 3 steps forward and backward only for low speed steps. Further, in each house, the transmission 32 is switched to the forward or reverse first speed stage, and each ultra-low speed stage is established when an ultra-low speed stage switch (not shown) is turned on. The dog clutch is engaged or disengaged by operating one of the front drive switches (not shown) provided in the carrier house 3 and the crane house 4, and four-wheel drive is enabled by the front drive switch.

Next, the steering system will be described with reference to FIGS. 2 to 3 in addition to FIG.

Steering wheel 40 arranged in the carrier house 3
Is a semi-integral power steering gearbox (hereinafter referred to simply as "semi-integral gearbox")
The front wheel 7 is steered by the link mechanism via the steering wheel 44, and the front and rear wheels 7 and 8 are steered by expanding and contracting the steering cylinders provided on the front wheel 7 and the rear wheel 8 respectively by the hydraulic pressure generated by the semi-integra gearbox 44. To do. On the other hand, the steering wheel 150 arranged in the crane house 4
Is a full-hydraulic steering system, which operates the steering cylinder by hydraulic pressure generated by a flow control valve (not shown) to steer the front wheels 7 and the rear wheels 8.

The steering wheel 40 of the carrier house 3 is connected to an input shaft of an L joint (direction changing gear device) 41 via a steering shaft 40a, a universal joint 40c, a steering shaft 40b, and a universal joint 40d, which are steering force transmission mechanisms, and The output shaft of the joint 41 is a universal joint 42a, which is also a steering force transmission mechanism, a rotating rod 42, a universal joint 42b.
Is connected to the input shaft of the semi-integer gearbox 44 via.

The front side members 9a of the front frame 9 extend forward from the left and right side members 10a of the main frame 10, and the L joint 41 is fixed to the left side wall of the left front side member 9a by protruding in the left lateral direction. The rotation of the steering shaft 40b that is attached to the bracket 9b that is connected to the input shaft is converted to a rotation rod 42 that is connected to the output shaft by converting the direction of the steering shaft 40b at a substantially right angle to the axial direction of the steering shaft 40b. That is transmitted, L
The joint 41 is a bevel gear that transmits the rotation of the input shaft to the output shaft.

Outrigger box 5a for housing the front outrigger 5
Is mounted on the lower wall of the front end of the left and right side members 10a of the main frame 10, and on the left and right side members 10a via the spacer 5b having a trapezoid (see Fig. 2) whose cross-sectional shape in the side view is wide at the top and short. The rotating rod 42 is fixed so as to be passed over, and the rotating rod 42 is formed by a side member 10a formed by a spacer 5b.
A space below and above the outrigger box 5a penetrates the spacer 5b and extends obliquely rearward from the L joint 41 toward the center of the chassis near the front axle 14.
The trapezoidal spacer 5b having a wide upper portion serves to disperse a load acting on the main frame 10 from the outrigger 5 via the outrigger box 5a.

A base end of a pitman arm 45 is connected to an output shaft projecting to a substantially central position on a lower surface wall of the semi-integer gear box 44, and the pitman arm 45 extends rearward along a center line of the chassis, and at the extended end thereof. Is connected to one end of a drag link 46 extending in the lateral direction (direction of the right front wheel 7) substantially in parallel with the front axle 14. The other end of the drag link 46 is connected to the tip of the knuckle arm 47.

The semi-integer gearbox 44 transmits the rotary motion transmitted to the input shaft via the rotary rod 42 to the output shaft, converts the rotary motion into the swing motion by the pitman arm 45, and moves the drag link 46 in the left-right direction (vehicle lateral direction). Direction) to steer the front wheels 7. The left and right front wheels 7 extend in the front-rear direction around the kingpin 50 and are connected by tie rods 52 connected to the rear ends of arms 51 that rotate integrally with the front wheels 7, and the left front wheels are steered as the right front wheel 7 is steered. 7 is also steered. The diff gearbox 38a of the front diff 38 has a bracket 3 on the front outer wall thereof.
8b are integrally projected, and the bracket 38b is connected to the front ends of the left and right arms 51 by a left front wheel steering cylinder 54 and a right front wheel steering cylinder 56, which will be described later.

In this way, the semi-inte gear box 44 is arranged at the chassis center position near the front axle 14, and the steering wheel 40 and the semi-inte gear box 44 are connected by the steering shafts 40a, 40b, the L joint 41, and the rotating rod 42. Since the drag link 46 is disposed substantially parallel to the front axle 14, it is not necessary to dispose the drag link 46 between the wheel and the chassis frame in parallel with the frame as in the conventional case. A large space can be secured between them, and the inconvenience that the wheels 7 interfere with the drag link during steering can be avoided. This is advantageous for mobile cranes, such as all-terrain mobile cranes, that need to use large-diameter tires, have a large steering angle to reduce the minimum turning radius, and enhance maneuverability on site.

Also, in the conventional configuration in which a large semi-inte gear box is arranged at the position where the L joint 41 of the present invention is arranged, it is necessary to extend the semi-inte gear box below the carrier house, that is, below the frame. , Furthermore, the link mechanism such as the drag link will greatly extend below the carrier house with the swinging motion of the pitman arm.
With this conventional structure, the steering link mechanism, which is an important safety component, causes the inconvenience that the approach angle and departure angle are determined, but in the present invention, the direction is changed by the L joint 41, and the steering shaft 40
The rotations of a and 40b are transmitted to the semi-integer box 44 by the rotating rod 42, and moreover, since the rotating rod 42 passes above the outrigger box 5a, the link mechanism etc. does not project below the carrier house 3, L joint
Since the 41 is small, it does not deteriorate the approach angle of the vehicle, and it does not require a complicated link mechanism. Further, the rotating rod 42 does not have a swinging motion like a drag ring, but only makes a rotating motion.
The space between 10 and the outrigger box 5a may be small.

The steering force transmission mechanism for passing the space between the frame 10 and the outrigger box 5a is not limited to the rotating rod 42 of the above-described embodiment, and may be a link mechanism such as a drag link.

Further, the hydraulic circuit portion of the steering device for supplying the operating oil to the steering cylinders 54, 56 and the like for steering is not directly related to the gist of the present invention, and therefore the description thereof will be omitted.

(Effect of the Invention) As described in detail above, according to the steering device for a mobile crane of the present invention, a spacer is interposed between the outrigger box and the chassis frame, and the steering force transmission mechanism is passed between the outrigger box and the chassis frame. Therefore, a complicated link mechanism is not required compared to a steering force transmission mechanism that is passed under the outrigger box, and the steering force transmission mechanism, which is an important safety component, should extend largely below the carrier house or below the outrigger. There is also no adverse effect on the approach angle and departure angle.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a side view showing the appearance of an all-terrain crane vehicle, and FIG. 2 is a side view showing the structure of a steering device on the carrier house side for steering front wheels by a link mechanism. , FIG. 3 is a top view of the steering apparatus. 1 ... All-terrain mobile crane, 3 ... Carrier house, 4 ... Crane house, 5 ... Outrigger, 5a ...
Outrigger box, 5b ... Spacer, 6 ... Outrigger, 7 ... Front wheel, 8 ... Rear wheel, 10 ... Main frame,
14,16 ... Axle, 30 ... Internal combustion engine, 32 ... Transmission, 40 ... Steering wheel, 40a, 40b ... Steering shaft, 41 ... L joint, 42 ... Rotating rod (steering force transmission device) , 44 …… Semi-integral gearbox, 45 …… Pitman arm, 46 …… Drag link, 47 …… Knuckle arm, 54,56 …… Steering cylinder, 150 …… Steering wheel.

Claims (1)

[Scope of utility model registration request] 1. A steering force of a steering wheel of a mobile crane, wherein an outrigger box is attached to a chassis frame between a steering wheel and a front axle, is transmitted to a wheel connected to the front axle via a steering force transmission mechanism, In a steering device for a crane vehicle that steers the wheels, a spacer is interposed between the outrigger box and the chassis frame, and the steering force transmission mechanism is passed between the outrigger box and the chassis frame. Steering device.