JPH107017A - Crawler crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower a mounting position of a revolving superstructure lower than conventionally and consequently to lower a position of the gravity center of a car body. SOLUTION: A car body frame 4 consists of a cylindrical body 4c an upper end of which opens and two frame bodies 4a, 4b respectively welded on side walls of this cylindrical body 4c, an upper end part of the cylindrical body 4c is formed as a ring seat part 40 to install a swing bearing on it, and an upper surface of the seat part 40 is welded against each of frame bodies 4a, 4b so that it comes to be roughly on the same level as an upper surface of each of the frame bodies 4a, 4b on a crawler crane constituted by installing the swing bearing on the car body frame 4 and supporting a revolving superstructure by this swing bearing free to revolve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a self-propelled crane.

[0002]

2. Description of the Related Art Self-propelled cranes have a background of being developed based on the structure of general automobiles and trucks. The structure is such that a body frame is disposed above axles via components such as a suspension device. An upper structure such as a crane device including a telescopic boom and a revolving superstructure having an operator cab is mounted on a body frame.

Conventionally, a revolving structure is mounted on a body frame, as shown in FIG.
A ring plate 102 is mounted on the base plate 00a by welding, a slewing bearing (not shown) is fixed on the ring plate 102, and the slewing body is pivotally supported by the slewing bearing.

[0004]

By the way, in a self-propelled crane, in order to improve the crane capacity and to be able to lift a heavy weight, the crane vehicle itself is increased in size and the body frame is accordingly increased. What is necessary is just to make the thing of the structure which can endure a big load.

However, since a self-propelled crane needs to travel between work sites by self-propelled on a general road, the total weight, axle load or height stipulated in the Road Traffic Law such as a vehicle restriction order is required. , And as a result, the weight and size of the body frame are restricted.

Further, even if the crane capability (lifting capability) is improved within the range of the limitation of the total weight and the like, there is a legal regulation that limits the overturn angle. That is, a crane truck
Since a heavy structure such as a boom is mounted on the vehicle body frame, the vehicle easily falls over when traveling on rough terrain or an inclined surface. Since the angle at which the vehicle falls (falling angle) is restricted to a certain degree or more by law, in the case of a crane truck with a large total weight, the position of the center of gravity should be adjusted as much as possible in order to clear the regulation of the falling angle. Must be lower. That is, it is necessary to mount the upper structure such as the revolving superstructure on the body frame at a position as low as possible.

However, in a conventional self-propelled crane, as described above (see FIG. 7), the body frame 100
Since the slewing bearing and the slewing body are mounted on the upper plate 100a via the ring plate 102, the mounting position of the slewing bearing is
Therefore, there is a certain limit to lowering the mounting position of the revolving unit, because the height of the revolving structure is lower than the upper surface position of the ring plate by the height of the ring plate 102. Also, in the case of a conventional self-propelled crane having a structure in which a body frame is arranged above the axle, the distance between the axle and the body frame does not interfere with the axle and the body frame due to the vertical movement of the axle during traveling. Therefore, there is a limit to lowering the position of the center of gravity by lowering the position of the body frame (the upper surface position of the body frame) (narrowing the space between the axle and the body frame).

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the mounting position of the revolving structure as compared with the related art, and as a result, to lower the center of gravity of the vehicle body. It is an object of the present invention to provide a self-propelled crane that is capable of operating.

[0009]

In order to solve the above problems, a self-propelled crane according to the present invention is configured as follows. That is, in a self-propelled crane having a revolving bearing mounted on a body frame and the revolving body being pivotably supported by the revolving bearing, the body frame has a cylindrical body having an open upper end, and a side wall of the cylindrical body. The cylindrical body has an upper end formed as a ring-shaped seat for attaching the slewing bearing, and an upper surface of the seat is formed in each of the frame bodies. Is welded to each frame body so as to be substantially flush with the upper surface of the frame.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 conceptually shows a first embodiment of the present invention. 1 (a) is a plan view of a body frame (a) of a self-propelled crane, (b) is a cross-sectional view taken along line AA of (a), and (c) is a B-line of (a). It is sectional drawing which follows the B line.

As shown in the figure, a body frame (a) is composed of a first and a second frame body (b) having a monobox shape.
(C) and a cylindrical body (d) which is welded to the first frame body (b) and the second frame body (c) and is open at the upper end thereof. The upper end of the cylindrical body (d)
It is formed as a ring-shaped seat (e) (corresponding to a conventional ring plate) to which a revolving bearing (not shown) for rotatably supporting the revolving body is mounted. Further, the cylindrical body (d) is formed so that the upper surface of the seat portion (e) is substantially flush with the upper surfaces of the upper plates (b) and (c) of the frame body (b) and (c). (B) Welded to (c).

According to such a configuration, the position of the ring plate (the seat portion (e) in the present embodiment) can be lowered by substantially the thickness of the upper plate of the body frame as compared with the conventional case shown in FIG. As a result, the center of gravity of the vehicle body can be lowered by lowering the mounting position of the revolving superstructure.

FIG. 2 shows an embodiment specifically illustrating this embodiment.
5 to FIG. As shown in FIG. 4, the self-propelled crane 1 of the present embodiment is a wheel crane (rough terrain crane) including a cab 2 that also serves as a crane cockpit and a driving cab, and a carrier as a traveling vehicle body. 1a and a crane device 1b mounted on the carrier 1a.

As shown in FIG. 4 and FIG.
a is composed of a body frame 4, and two drive shafts 10, 10 are incorporated in the body frame 4. Drive shaft 10,
10 has both ends protruding to the side of the vehicle body frame 4 and has wheels 15 at the protruding ends.

A revolving structure 8 having a cab 2 is rotatably mounted on the body frame 4 via a revolving bearing 6. A telescopic boom 5 is attached to the revolving unit 8 so as to be able to undulate.

An engine 25 is mounted on a rear portion of the body frame 4, and the driving force of the engine 25 is
A transmission shaft 17 such as a propeller shaft for transmitting to the transmission 10, a transmission 18, a differential device 19, and the like are housed in the vehicle body frame 4. Further, a torque rod 28 that connects the drive shaft 10 and the body frame 4 to transmit torque between the drive shaft 10 and the body frame 4 is also provided inside the body frame 4.

The body frame 4 has outrigger housings 12a and 12b before and after it. The outrigger receiving portions 12a and 12b have telescopic beams 14 that protrude to the side of the vehicle body frame 4 and support the vehicle body during crane operation.
(See FIG. 5).

As shown in FIG. 2, the vehicle body frame 4 is welded to the first and second frame members 4a and 4b, and between the first and second frame members 4a and 4b. And a cylindrical body 4c.

First and second frame members 4a, 4b
Is composed of a top plate 52, a bottom plate 53, and two side plates 50 and 51 which connect the top plate 52 and the bottom plate 52b to face each other, and have a long cylindrical monobox structure opened at both left and right sides. Has made. Therefore, the frame body 4
a, 4b are in a state where their cross-sectional shapes are closed by plates 50, 51, 52, 53, and a housing space capable of housing the above-described drive mechanisms 10, 17, 18, 19, 28, etc. is formed therein. Is done. Also, as shown, the side plates 50,
51 is provided with a through hole 29.
The drive shaft 10 penetrates through the frame bodies 4a and 4b.

The cylindrical body 4c is formed in a substantially cylindrical shape with an opening (opening 41) at the top and bottom, and has two openings 4 opposed to the side surfaces thereof.
4,45. The upper end of the cylindrical body 4c is formed as a ring-shaped seat portion 40 to which the swing bearing 6 that supports the swing body 8 so as to be able to swing is attached.

The upper surface of the seat 40 is fixed to the upper plates 52, 52 of the cylindrical body 4c with the openings 44, 45 facing the end openings of the frame bodies 4a, 4b.
Is welded to the frame bodies 4a and 4b so as to be substantially flush with the upper surface of the frame body. The welded state is shown in FIG. In this welding state, the internal space of the cylindrical body 4c communicates with the internal spaces of the frame bodies 4a and 4b through the openings 44 and 45 formed on the side surfaces of the cylindrical body 4c, and cooperates with the internal spaces of the frame bodies 4a and 4b. Work to drive mechanisms 10, 17,
An accommodation space for accommodating 18, 19, 28 and the like is formed.

A plurality of bolt holes 42 for fixing the slewing bearing 6 with bolts are formed in the seat 40 of the cylindrical body 4c. A plurality of ribs 43 are provided on the inner peripheral surface of the cylindrical body 4c along the height direction of the cylindrical body 4c.
These ribs 43 are for compensating the strength of the cylinder 4c, and exhibit an effect of preventing buckling particularly when the cylinder 4c is formed of a thin plate for weight reduction.

In this embodiment, the axle penetrating into the body frame 4 (frame bodies 4a, 4b) is the drive shaft 10
However, needless to say, it is not necessary to be the drive shaft. Also, not all of the axles need to pass through the body frame 4.
Further, in this embodiment, the body frame 4 is formed in a shape having a closed cross section over substantially the entire length, but a maintenance opening may be partially provided in the bottom plate 53, the side plates 50, 51, and the like. .

As described above, in the self-propelled mobile crane vehicle 1 of the present embodiment, the upper surface of the seat 40 (corresponding to a conventional ring plate) to which the swing bearing 6 is attached is attached to the upper plate 52 of the frame bodies 4a and 4b. , 52 are configured to be able to be lowered to a position substantially flush with the upper surface of the vehicle body 52, and the drive shaft 10 is made to penetrate through the vehicle body frame 4. Therefore, various operational effects as described below are obtained.

First, in this embodiment, the vehicle body frame 4 is
Two frame members 4a and 4b and these frame members 4
a, 4b and a cylindrical body 4c having a seat 40 for fixing the slewing bearing 6 separately, and the upper surface of the seat 40 is made substantially flush with the upper surfaces of the frame bodies 4a, 4b by welding. Position (the upper surface position of the seat 40 is
Lower than the thickness of the upper plate of the body frame as compared with the prior art shown in FIG. 1), and consequently, the mounting position of the revolving unit 8 is lowered to lower the center of gravity of the body. And the stability of the vehicle body can be increased.

However, in the case of the structure of the present embodiment, the lowering of the position of the center of gravity of the vehicle body is not limited to substantially the thickness of the upper plate of the vehicle body frame. That is, in this embodiment, the vehicle body frame 4
With the axle 10 penetrating the inside, the body frame 4
In addition to the mount position of the revolving body 8 with respect to the vehicle body 4, the body frame 4 itself (the upper surface position of the body frame 4) can be sufficiently lowered. That is, the ground height of the vehicle body frame 4 can be made lower than before. Therefore, the revolving unit 8 including the boom and the like can be necessarily lowered, and the position of the center of gravity of the vehicle body can be sufficiently lowered. Therefore, the falling angle can be increased, and the stability during crane operation increases.

Further, since the upper surface position of the body frame 4 can be lowered as described above, the rigidity of the body frame 4 can be enhanced. The rigidity of the body frame is
This is an important factor in improving crane capacity. That is, when a load is lifted by the boom and a crane operation is performed, a bending or twisting force acts on the body frame. In particular, when the boom is lifting a load on the side of the vehicle body, a large torsion acts due to a bending moment about the longitudinal axis of the vehicle body frame 4. Therefore, in the case of a body frame, it is particularly necessary to increase the rigidity against this torsion. Rigidity against torsion is related to the second moment of area specific to the cross-sectional shape. Particularly, in the case of a body frame formed of a plate material in a box shape, the rigidity is large depending on the thickness of the body frame and the area surrounded by the plate. Comes involved. If this area can be increased and the section modulus can be increased, a body frame resistant to torsion can be formed.

In this regard, as described above, the self-propelled crane 1 of the present embodiment can sufficiently lower the position of the center of gravity, so that there is a margin in the height direction, and therefore, the body frame 4 itself can be provided. (Not the ground height of the upper surface of the vehicle body frame 4) as compared with the related art, the cross-sectional area of the vehicle body frame 4 can be increased. That is, in the structure in which the axle 10 is taken into the body frame 4 as in the present embodiment, the body frame 4 can be lowered to the position of the conventional wheel, and accordingly, the conventionally permitted body frame 4 to allow a margin in the height direction. As a result, the height of the body frame 4 itself can be increased by the extra height. The fact that the height of the body frame 4 itself can be increased means that the section modulus of the body frame 4 can be increased in the height direction. Therefore, the section modulus of the body frame 4 can be increased, and the bending strength of the body frame 4 can be increased. This is because, when the frame 4 is raised in the height direction and the section modulus is increased in the height direction rather than in the width direction, the section modulus with respect to the longitudinal axis of the frame 4 can be increased. This is because the strength against the moment can be increased.

As described above, if a large frame space is secured by lowering the frame 4 and thereby high frame rigidity can be secured, the frame structure is unnecessarily increased in order to increase the rigidity in the limited frame space as in the conventional case. Eliminates the need for increased complexity and weight. That is, the conventional body frame has a limited height as described above due to the configuration arranged above the axle, and in order to increase rigidity in the limited narrow frame space,
It has a bag structure in which a plurality of cross members 103 (see FIG. 7) are provided in a cross-girder shape. Therefore, the structure is complicated and the weight is large. On the other hand, the frame 4 of the present embodiment
By lowering itself down, it is possible to obtain the high rigidity as described above by its sufficient height, and at the same time, it is possible to realize a very simple monobox structure. It can be simplified and consequently its weight can be greatly reduced.

Needless to say, in this embodiment, the revolving body mounting portion of the body frame 4 is formed as a cylindrical body 4c having a seat portion 40, and two revolving body mounting portions of the body frame are provided as shown in FIG. Since the plate structure (102, 100a) is not used, the weight of the frame 4 can be reduced by that much, but the rigidity is increased and the structure is simplified by lowering the frame 4 itself downward. Thus, the reduction in weight that can be obtained is further increased, and the surplus weight can contribute to the improvement of the lifting capacity. This is very beneficial in improving crane capacity in a limited total weight.

In the self-propelled crane 1 of the present embodiment, the opening 41 is provided at the upper end of the cylindrical body 4c of the body frame 4, so that the maintenance of the drive mechanism disposed in the internal space of the frame 4 can be performed. It will be easier.

Further, the body frame 4 of the present embodiment has a frame body 4a, 4b having a monobox structure on both sides of a cylindrical body 4c.
Are formed by welding, so that the number of welding points is smaller than in the conventional case, and the production becomes easier. In addition, since a large load received from the revolving structure 8 is received by the entire frame 4, the load can be largely dispersed and concentration of stress can be prevented.

Conventionally, the body frame 4 could not be placed at a very high position due to height restrictions or the problem of the center of gravity due to the Road Traffic Law. Therefore, the frame 4 can only be extended in the width direction. Although the strength could not be ensured, the structure in which the axle 10 was taken into the body frame 4 as in the present embodiment allows the body frame 4 to be expanded not only in the width direction but also in the height direction. Therefore, the cross-sectional area of the vehicle body frame 4 can be made larger than before.

In the present embodiment, various components such as the transmission shaft 17 and the transmission 18 are arranged in the frame 4 as the frame 4 is lowered, so that these components are mounted on the road surface. Can be prevented from being damaged by the obstacle.

Further, in this embodiment, since it is possible to secure sufficient strength by staking in the height direction without expanding the frame 4 in the width direction, the width of the body frame 4 is reduced and the steering angle is reduced. It can be large. Therefore, the turning radius of the crane can be reduced, and the crane can easily enter a narrow alley with few turns.

FIG. 6 conceptually shows a second embodiment of the present invention. 2 (a) is a plan view of the body frame (a) of the self-propelled crane, (b) is a cross-sectional view taken along the line CC of (a), (c) is a D-line of (a). It is sectional drawing which follows the D line.

As shown in the figure, the vehicle body frame (a) has first and second frame bodies (b) of a monobox shape.
(C), and a cylindrical body (d) which is welded between the first frame body (b) and the second frame body (c) and whose upper end is open. The cylindrical body (d) is formed in a truncated cone shape, and its upper end has a ring-shaped seat (e) (a conventional ring plate) to which a swing bearing (not shown) that supports the swing body so as to swing is attached. ). Also, the cylindrical body (d) has an upper surface of the seat portion (e) and an upper plate (b ') (c') of the frame body (b) (c).
Frame (b) (c) so that it is almost flush with the upper surface of
Welded against.

According to such a configuration, similarly to the first embodiment, the ring plate (the seat (e) in the present embodiment).
Can be lowered by approximately the thickness of the upper plate of the vehicle body frame as compared with the related art shown in FIG. 7, and as a result, the mounting position of the revolving structure can be lowered to lower the center of gravity of the vehicle body.

[0039]

As described above, according to the self-propelled crane of the present invention, the revolving unit can be mounted at a lower position than before, and consequently the center of gravity of the vehicle body can be lowered.

[Brief description of the drawings]

FIG. 1A is a plan view of a body frame of a self-propelled crane according to a first embodiment of the present invention, and FIG.
FIG. 3C is a cross-sectional view along the line A, and FIG. 3C is a cross-sectional view along the line BB in FIG.

FIG. 2 is an exploded perspective view of a vehicle body frame according to a specific example of the first embodiment of the present invention.

3A is a plan view of the vehicle body frame of FIG. 2, and FIG.
3A is a front view of the vehicle body frame of FIG. 3A, and FIG. 3C is a side view of the vehicle body frame of FIG.

FIG. 4 is an overall view of a self-propelled crane provided with the vehicle body frame of FIG. 2;

FIG. 5 is a plan view showing an arrangement state of a drive mechanism inside a body frame in the self-propelled crane of FIG. 4;

FIG. 6A is a plan view of a body frame of a self-propelled crane according to a second embodiment of the present invention, and FIG.
FIG. 3C is a cross-sectional view along the line C, and FIG. 3C is a cross-sectional view along the line DD in FIG.

7A is a plan view of a body frame of a conventional self-propelled crane, FIG. 7B is a cross-sectional view taken along line EE of FIG.
(C) is sectional drawing which follows the FF line of (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Self-propelled crane 4 ... Body frame 4a ... 1st Grame body 4b ... 2nd Grame body 4c ... Cylindrical body 40 ... Seat part

Claims (3)

[Claims] 1. A self-propelled crane having a revolving bearing mounted on a body frame and the revolving body being pivotally supported by the revolving bearing. It consists of two frame bodies welded to the side walls of the body, respectively, and the upper end of the cylindrical body is formed as a ring-shaped seat for attaching the slewing bearing,
A self-propelled crane characterized by being welded to each frame so that the upper surface of the seat is substantially flush with the upper surface of each frame. 2. Each of the frame bodies includes an upper plate, a bottom plate,
The upper plate and the bottom plate are connected to each other, and two side plates facing each other are formed in a substantially closed cross section, and an axle passes through the frame through the side plate of the frame. Item 1. A self-propelled crane according to item 1. 3. A self-propelled crane having a revolving body mounted on a vehicle body frame, wherein the vehicle body frame is welded to a cylindrical body that rotatably supports the revolving body and a side wall of the cylindrical body. Each frame body is formed in a shape whose cross section is substantially closed by an upper plate, a bottom plate, and two side plates that connect the top plate and the bottom plate and oppose each other, A self-propelled crane, wherein an axle passes through the frame through a side plate of the frame.