JPH07232622A - Outrigger device of truck crane - Google Patents

Abstract

PURPOSE:To drastically improve the lifting capacity of a crane compared with a customary one in the range of the regulated size of a truck crane. CONSTITUTION:Hydraulically actuated assistant jacks 14 respectively having ground output unable to lift a truck crane are fitted on both sides of a turnable fitting part 6 for turning a crane of a vehicle body frame 1 lifted by means of first jacks 20 of front and rear outriggers 18, 19, an accumulator of which gas enclosed pressure is higher than that of an oil chamber is connected to a high pressure side oil chamber at driving the jacks 14 to ground, and when a suspending load is perfectly supported with the ground through the front and rear outriggers, a part of the load is received with the assistant jacks controlled by the accumulator, so as to reduce the load applied on the front and rear outriggers. It is favorable that the assistant jacks are positioned in the vicinity of the center part between the front and rear outriggers, and when the fitting metals of the assistant jacks are formed into beam shapes, it is favorable that second jacks 24 respectively having ground output unable to lift the outrigger fitting part of the truck crane are fitted on the middle parts of both sides horizontal beams of the front and rear outriggers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outrigger device for a mobile crane having a swing crane mounted on the automobile.

[0002]

2. Description of the Related Art Conventionally, front and rear outriggers, each having a vertical first jack attached to the tip of a horizontal beam extending from both sides of the vehicle body frame, are provided on the vehicle body frames before and after a turntable mounting portion for turning a crane. Cranes are commonly used, and in a fully swinging type crane that can perform cargo handling work on the entire circumference, a front end jack that cannot lift the front end of the vehicle is attached to the front end of the body frame, and At the rear end, a rear outrigger that cannot lift the rear end of the mobile crane is attached so as to project rearward.

Since the length, width, height, etc. of such a mobile crane are restricted by laws and regulations, a crane swivel base for removing the telescopic boom while traveling on the road or for supporting the telescopic boom in a cantilevered manner. As shown in Japanese Patent Laid-Open No. 63-305061, the horizontal beams of the front and rear outriggers are composed of a pair of left and right multi-stage telescopic beams, and a ground output that cannot be lifted by a crane vehicle is provided between them. By installing a second jack that generates a load, a lateral tilt (twist) of the vehicle body frame due to a difference in bending and bending caused between a pair of left and right telescopic beams of front and rear outriggers is prevented at the time of side loading and unloading work. I was trying to improve the lifting ability.

However, if the maximum lifting capacity is to be remarkably increased than before, the weight of the telescopic boom, the crane swivel base, etc. and the length of the vehicle body frame between the front and rear outriggers will increase, whereas the structural restrictions imposed by the aforementioned regulations will increase. Because it is difficult to increase the bending rigidity of the horizontal beams of the front and rear outriggers and the body frame, the holding of the body frame or the crane truck during crane turning during cargo handling becomes unstable, and during side hanging cargo handling work, The working radius of the crane increases mainly due to the left-right inclination of the vehicle body frame caused by the difference in bending and bending between the pair of left and right telescopic beams of the front and rear outriggers, so the crane safety device operates and the load of the rated load can be lifted. The crane may be difficult to turn smoothly due to bending and bending of the body frame itself.

[0005]

The problem to be solved is that if the maximum lifting capacity is remarkably improved as compared with the conventional one within the size limitation according to the regulations, the front-back The left and right inclination (torsion) of the vehicle body frame based on the difference in bending and bending generated between the left and right horizontal beams of the outrigger becomes excessive, and the bending and bending of the turntable mounting portion of the vehicle body frame becomes excessive.

[0006]

According to the present invention, hydraulically actuated vertical auxiliary jacks are detachably attached to both sides of a vehicle body frame of the turntable attachment portion, and ground driven when the crane vehicle is lifted by front and rear outriggers. The auxiliary jacks on both sides are limited so that the auxiliary jack mounting portion of the crane vehicle cannot be lifted up, and the ground output of the auxiliary jacks is limited, and the gas filling pressure is high side oil when the auxiliary jacks are grounded. The most main feature is that pressure accumulators having a pressure higher than the chamber pressure are connected to the high-pressure side oil chambers, respectively, so that the pressure accumulators operate during cargo handling work with a large load. The auxiliary jacks on both sides should be located near the center between the front and rear outriggers.If the auxiliary jacks are attached to the ends of the detachable beam-shaped mounting brackets that project laterally from the body frame, both sides of the front and rear outriggers should be horizontal. It is good to install the second jack in the middle of each beam.

[0007]

FIG. 6 is a side view of an embodiment of the present invention in which the maximum lifting capacity is increased to 500 tons all at once. A turntable 4 of a crane swivel base 3 in which a detachable multi-stage telescopic boom 2 is cantilevered so that the detachable multi-stage telescopic boom 2 is integrally welded, is detachably attached to a turntable attachment portion 5 on the vehicle body frame 1. , The crane swivel base is fully swivelable, and the body frame 1 has front wheels 6,
It is suspended on the axles 7 and 8 and the axles of the rear wheels 9, 10 and 11 so that only the rear wheels 9 and 10 are non-steering wheels. Reference numeral 12 denotes an automobile cab attached to the negative side of the front end of the vehicle body frame 1, and 13 denotes a cover of the automobile engine.

FIG. 1 is a plan view of the entire outrigger device without the crane swivel, and FIG. 2 is a vertical sectional front view corresponding to the XX cross section of FIG. 1, in which the left and right auxiliary jacks 14 are respectively provided at the tips. The bases of the attached beam-shaped mounting members 15 are rigidly fixed to both sides of the body frame of the turntable mounting portion 5 located behind the center of gravity G1 of the traveling crane, respectively, just above the rear wheels 9 and 10. The beam-shaped mounting member 1 of the auxiliary jack 14 fitted and inserted in the horizontal cylindrical portion 16
5 is attached to and detached from the vehicle body frame by a stopper 15a fixed thereon so as to come into contact with the tubular portion 16 and a separable pin coupling portion 17 between the beam-shaped mounting member and the tubular portion 16. It is mounted so that the distance L between both auxiliary jacks is L
Is larger than the width of the vehicle so that the beam-shaped mounting bracket protrudes.

Reference numerals 18 and 19 denote front and rear outriggers having the same structure as in the prior art. Each of the outriggers has a hydraulically actuated first jack 20 at the end of a horizontal beam that is installed to the left and right of the body frame 1. The beam mounting fittings 15 of the auxiliary jacks on both sides of the vehicle body frame are attached.
It is positioned near the center between the mounting portion of the front outrigger 18 to the front end of the highly rigid portion of the vehicle body frame 1 and the mounting portion of the rear outrigger 19 to the rear end of the highly rigid portion of the vehicle body frame. It is attached to the vehicle body frame of the turntable attachment portion 5 slightly forward of the crane turning center 0.

The horizontal beams of the front and rear outriggers 18, 19 have a telescopic beam 22 in a beam guide portion 21 attached to the lower side of the vehicle body frame 1 as shown in FIG. Insert it in a telescopic manner by 26,
A box-shaped coupler 25 is added to the end of the telescopic beam and is provided at the base of the beam 23.
The second jack 24 for output to the ground, which is detachably joined and fixed by means of c and which is joined to the first jack 20 and is capable of lifting the tip of the beam 23 and the corresponding outrigger mounting portion of the crane vehicle, cannot be extended. Each of the outriggers is attached to the tip of each of them, and the other one side portion of the outrigger is also configured to be bilaterally symmetrical to this, but the front and rear outriggers are not limited to this configuration, and the left and right horizontal beams that are integrally fixed to each other are formed. An arbitrary structure can be adopted, such as a structure in which the wheel-equipped outriggers to which the first jack 20 and the second jack 24 are attached respectively at the tip and the middle are detachably fixed to the lower surface of the vehicle body frame.

Reference numeral 27 in FIG. 1 denotes a front end jack attached to the front end of a portion of the front portion of the vehicle body frame having a low rigidity, and 28 denotes a rear end of a rear end outrigger 29 which projects rearward from the rear end of the vehicle body frame and is fixed in the same manner as before. As shown in the plan view of FIG. 4, the respective jacks 27, 20 and 28 described above are located at the tops of the hexagonal CDEFHJ, and the telescopic boom 2 and the crane swivel 3 and the load at the tip of the boom. The total center of gravity G2 of the revolving structure K is
Is located within a safety limit circle M centering on the center, and when the suspended load has a rated load, it is located on the safety limit circle M.

FIG. 5 schematically shows the hydraulic circuit of the device of the present invention, in which a directional control valve 31 connected to the discharge port of the hydraulic pump 30.
A high pressure side oil chamber (upper oil chamber) 34 at the time of grounding driving of each auxiliary jack 14 is connected in parallel to the A port of each of the above through an on / off valve 32 and a pilot operation check valve 33. The low-pressure side oil chamber 35 is connected in parallel to the port B of the directional control valve when the auxiliary jacks are grounded. 36 and 37 are hydraulic hoses connected to the oil passages so that the auxiliary jacks can be attached to and detached from the mobile crane, 38 and 3 respectively.
Reference numeral 9 is a quick joint at each end of the hydraulic hose, and 40 is first and second jacks 2 for hydraulic control of front and rear outriggers 18, 19 which are similarly connected in parallel to the A and B ports of the direction switching valve 31.
It is a control circuit for 0, 24, front end jack 27, and rear end jack 28.

Reference numeral 41 denotes a main relief valve connected to the discharge port of the hydraulic pump 30, and a vent port 42 of the main relief valve 41 has a normally open valve 43 communicating the vent port with the tank T and a direction switching valve. 44 and 45 are connected in parallel,
The bidirectional switching valve switches either one of them and closes the normally open valve 43 to make the set pressure different.
Any one of the small relief valves 46, 47, 48, 49 is selectively connected to the vent port 42, and the main relief valve 4
The set pressure of 1 can be adjusted to 4 types of high and low.

Therefore, when the main relief valve 41 is set to the minimum pressure (for example, 30 kilograms per square meter), the directional control valve 31 is switched to the left position in the figure, and the double-intermittent valve 32 is opened to support both auxiliary valves. Upper oil chamber 3 of jack 14
The pump discharge hydraulic pressure is simultaneously supplied to 4, and both the auxiliary jacks are grounded. Further, if the direction switching valve 31 is switched to the right position in the figure and both the intermittent valves 32 are opened,
The pump discharge hydraulic pressure is supplied to the oil chamber 35, and the check valve 33 is opened by the pressure of the pilot oil passage 33a, so that both auxiliary jacks 14 contract.

Reference numeral 50 denotes a Prada type pressure accumulator which is constantly connected to the high pressure side oil chamber (upper oil chamber) 34 when the auxiliary jacks 14 are grounded, and the gas charging pressure of the pressure accumulator 50 is the grounded drive. At a pressure higher than the pressure in the high pressure side oil chamber 34 at the time,
When the maximum lifting capacity is 400 to 500 tons, this gas charging pressure is 5 to 6 times the pressure of the high pressure side oil chamber 34 at the time of the ground drive.
It is about double.

Each of the other jacks 20, 24, 27, 28
In the same manner as that of the auxiliary jack 14, a check valve for pilot operation is inserted into the pump discharge pressure oil supply path to the high pressure side oil chamber at the time of the grounding drive, respectively, and the contraction of each of the jacks which have been grounded. Although the structure for blocking is provided as before, a pressure accumulator is not connected to the high pressure side oil chamber at the time of grounding drive.

According to the above construction, when a crane vehicle in a traveling posture in which the retracted boom 2 is swung forward as shown in FIG. Front and rear outriggers 18 and 1 protruding on both sides
The first jack 20 at the tip of the horizontal beam of 9 is driven to ground, and each grounding board 20a grounds each first jack 20 to
As shown in FIGS. 2 and 3, the body frame 1 is lifted horizontally from the ground, and then the second jacks 2 of the front and rear outriggers 2 are provided.
4 is grounded to bring each grounding board 24a into pressure contact with the ground, but the output of the second jack 24 is a grounded output that cannot lift the corresponding outrigger mounting portion of the crane vehicle, and therefore four There is no fear that the horizontal posture of the vehicle body frame 1 lifted by the first jack 20 will change.

Next, the auxiliary jacks 14 mounted via the mounting brackets 15 on both sides of the vehicle body frame of the turntable mounting portion 5 located rearward of the center of gravity G1 of the traveling mobile crane are simultaneously grounded to drive the respective grounding boards. 14a is brought into pressure contact with the ground, but its ground output cannot raise the auxiliary jack mounting portion of the crane vehicle, so there is no fear that the horizontal posture of the vehicle body frame will change.

In this state, when the revolving structure K is set to the position shown in FIG. 4, for example, to start the side loading and unloading work, the weight of the revolving structure K acting on the total center of gravity G2 is displayed on the turntable mounting portion 5 of the vehicle body frame. A moment load equal to the product of the swing radius acts on the vertical plane including the boom 2, and at the same time, a vertical load equal to the weight of the swing body acts on the swing center 0. This vertical load depends on the swing of the swing body. It is constant regardless of. Also, in the moment load, the body frame 1 becomes a problem.
The torsional moment component of is decreased as the revolving structure turns in the direction of decreasing the distance b between the total center of gravity G2 and the straight line EH, and between the total center of gravity and the center line connecting the both side auxiliary jacks 14 and 14. Since the revolving structure increases as the revolving structure revolves in the direction of decreasing the distance a, this torsion moment component is maximized when the boom 2 is positioned substantially directly above each auxiliary jack 14.

When the pressure in the upper oil chamber 34 of the auxiliary jack due to the vertical load and the torsional moment component of the moment load becomes higher than the gas charging pressure of the pressure accumulator and the pressure accumulator operates, the revolving structure K of the revolving structure K is operated. The auxiliary jacks 14 and 14 on both sides of the turntable mounting portion 5 are both vertically loaded in response to slight bending flexure of the vehicle body frame that occurs when the boom 2 lifts a load in advance or bending flexure of the horizontal beams of the front and rear outriggers. Although the compression bias is applied, the auxiliary jack 14 on the side of the total center of gravity G2 (compression side) of the body frame 1 is further compressed by the torsion moment component, while the auxiliary jack 14 on the opposite side (tensile side) is pulled by tension. Therefore, the force acting on the tension side auxiliary jack is significantly reduced, and this force is transmitted to the front and rear outriggers as the twisting force of the vehicle body frame. It will be described side auxiliary jacks.

Therefore, the pressure in the upper oil chamber 34 of the compression side auxiliary jack 14 is determined by the gas filled rubber bag in the pressure accumulator 50 depending on the bending deflection of the body frame and the horizontal beams of the front and rear outriggers. As a result of being compressed by the amount of oil discharged from 34, it rises. That is, while the load is large so that the pressure accumulator operates, the ground reaction force of the compression side auxiliary jack 14 gradually increases as the load increases.

The amount of compression of the compression side auxiliary jack 14 increases as the load increases, and the horizontal beams of the front and rear outriggers and the flexure of the vehicle body frame 1 also increase as the load increases. Since the load is shared by the front and rear outriggers 18 and 19 and the auxiliary jack, the load is supported, and the rated load can be improved according to the load of the auxiliary jack. When the load decreases so that the pressure in the upper oil chamber 34 of the compression side auxiliary jack becomes lower than the gas charging pressure of the pressure accumulator, the accumulator does not operate, so that the auxiliary jack is a substantially rigid body to support the load.

-When the one-way total center of gravity G2 moves in the triangle EFH or moves in the triangle CDJ, the above vertical load always acts on the turntable mounting portion.
Although it is similar to the case of the side loading and unloading work, the aforementioned moment load mainly acts on the vertical plane of the vehicle body frame 1 in the front-rear direction, so that the distance between the outriggers 18 and 19 before and after receiving the moment load is large. As a result, the increase in the ground reaction force of the front and rear outriggers is slight and there is no problem. This is because the safety limit circle M is slightly offset to the front of the vehicle due to the influence of the center of gravity of the vehicle itself of the mobile crane, which is ignored when hanging sideways.

As shown, a pair of left and right auxiliary jacks 1
4 and 14 are arranged near the center between the front and rear outriggers 18 and 19 in order to reduce the vertical load and the moment load which are reduced by the ground reaction force of the auxiliary jacks.
This is to prevent the horizontal posture of the vehicle body frame from deviating when the load is hoisted by transmitting the vehicle body frame 1 to the front and rear outriggers 18 and 19 that support the vehicle body frame 1 in a balanced manner in advance.

The embodiment of a very large crane vehicle in which the telescopic boom 2 and the crane swivel 3 can be attached to and detached from the vehicle body frame 1 has been described above. However, it is a large vehicle that can be run on the road with the telescopic boom and the crane swivel attached. -Shaped crane trucks have a short lateral extension of the front and rear outriggers, so the ground output of both side auxiliary jacks that are detachably attached to the body frame of the turntable attachment section is enhanced by the auxiliary jack attachment section of the crane vehicle. It is also possible to connect to each of the high pressure side oil chambers a pressure accumulator which is restricted so as not to be obtained and whose gas filling pressure is higher than the pressure of the high pressure side oil chamber at the time of grounding driving of each auxiliary jack.

[0026]

As described above, according to the present invention, when the load during the cargo handling work is large, when the load is completely supported on the ground through the outriggers on the front and rear of the body frame, a part of the load is removed. Since it is configured to receive with auxiliary jacks that are detachably attached to both sides of the turntable attachment part of the vehicle body frame, it is possible to obtain an outrigger device that can significantly improve the lifting capacity of the crane within the range of the regulation size of the crane vehicle. There is an effect that can.

By locating the auxiliary jacks on both sides near the center of the front and rear outriggers, it is possible to prevent the level difference of the vehicle body frame or the crane vehicle between the time when the outrigger device is installed and the time when the load is lifted, and the crane safety device. The operating accuracy of can be improved compared to the conventional one.

Further, the mounting member of the auxiliary jack is constituted by a beam-shaped mounting member whose base portion is attachable to and detachable from the vehicle body frame, and the cranes are respectively provided in the middle of the horizontal beams of the front and rear outriggers which are respectively extended to the left and right from the vehicle body frame. If a second jack with a ground output that cannot lift the corresponding outrigger mounting portion of the vehicle is attached, the maximum lifting capacity of the crane can be improved to about 500 tons.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention excluding a crane swivel base.

FIG. 2 is a vertical cross-sectional front view corresponding to the XX section in FIG.

FIG. 3 is a rear view showing a rear outrigger on one side in a longitudinal section.

FIG. 4 is a plan view for explaining the operation of the embodiment of the present invention.

FIG. 5 is a hydraulic circuit diagram of an embodiment of the present invention.

FIG. 6 is a side view of a mobile crane to which the present invention is applied.

[Explanation of symbols]

 1 Body frame 2 Telescopic boom 3 Crane swivel 5 Turntable mounting part 14 Auxiliary jack 15 Beam mounting bracket 18 Front outrigger 19 Rear outrigger 20 First jacking 24 Second jacking 33 Pilot operated check valve 34 Grounding drive High pressure side oil chamber 50 Accumulator K Revolving structure G2 Total center of gravity M Safety limit circle

Claims (3)

[Claims] 1. A crane comprising front and rear outriggers, each of which has a vertical first jack attached to a tip of a horizontal beam which is installed on both sides of the vehicle frame before and after the turning table for turning the crane. In the vehicle, hydraulically actuated vertical auxiliary jacks are removably attached to both sides of the vehicle body frame of the turntable attachment portion, and the auxiliary jacks on both sides that are grounded when the crane vehicle is lifted by front and rear outriggers are In order not to lift the auxiliary jack mounting part of, the output of the auxiliary jack to the ground is limited, and the gas charging pressure is a pressure accumulator that is higher than the pressure of the high pressure side oil chamber at the time of ground driving of each auxiliary jack. A crane characterized in that the accumulators are respectively connected to the high-pressure side oil chambers so that the accumulators are activated during heavy load handling work. Car outrigger device. 2. Mounting brackets for the auxiliary jacks are detachably attached to both sides of the turntable mounting body frame so that the auxiliary jacks on both sides are located near the center between the front outriggers and the rear outriggers. The outrigger device for a mobile crane according to claim 1. 3. An auxiliary jack is vertically attached to the tip of a beam-shaped mounting bracket whose base is detachably planted in the vehicle body frame so as to project laterally from the vehicle body frame, and to the left and right of the vehicle body frame, respectively. 3. The crane according to claim 1 or 2, wherein a second jack having a ground output which is not capable of lifting the corresponding outrigger mounting portion of the crane vehicle is mounted in the middle of the horizontal beams of the front and rear outriggers. Car outrigger device.