JP2017132365A - Suspension device for work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension structure for a self-propelled work machine that has a sufficient extension/contraction stroke and can guarantee sufficient strength of a suspension of a vehicle by suppressing the total height of the work machine as low as possible.SOLUTION: Upper ends of suspension cylinders 22, 29 having lower ends connected to king pins 18, 27 of a front axle 15 and a rear axle 24 are mounted to a vehicle body frame 2 via brackets 23, 30 projecting to the upper side of the vehicle body frame 2 and extending sideways. Upper ends of suspension cylinders 38 each having a lower end connected to an axle beam 32 of an intermediate axle 31 are mounted to side surfaces of the vehicle body frame 2. Due to this configuration, a bending moment applied to axle beams 16, 25 of front and rear axles 15, 24 is reduced and extension/contraction strokes of the suspension cylinders 22, 29 are guaranteed. In addition, the configuration prevents components of a suspension structure supporting the intermediate axle 31 from projecting to the upper side of the vehicle body frame 2, so as to allow mounting of a turning body coming to close contact with the vehicle body frame 2.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a suspension structure for a self-propelled working machine, and more particularly to a suspension structure for a self-propelled working machine having a total number of three or more axles provided with a turning body on a body frame.

Self-propelled working machines such as crane trucks are required to have high-rigidity work equipment and body frames as the suspended loads and loads to be handled increase in size. The weight of the vehicle body tends to increase, and sufficient strength is also required for the underbody of the vehicle.
On the other hand, there is a demand for keeping the overall height of the self-propelled working machine as low as possible in order to maintain running stability.

Here, as means for giving sufficient strength to the underbody of the vehicle, for example, as disclosed in Patent Document 1, left and right suspension cylinders that support the front shaft and left and right suspension cylinders that support the rear shaft, respectively. One end (upper end) of each of the left and right suspension cylinders is attached to the vehicle body frame via left and right suspension cylinder mounting brackets extending to the side of the vehicle body frame. A suspension device is known that is attached to the upper ends of left and right king pins along a central axis.
The technical idea is that the other end (lower end) of each of the left and right suspension cylinders is attached to the upper end portion of the left and right king pins along the center axis of the steering of each wheel, whereby the other end ( Compared to the conventional suspension system with the lower end attached to the left and right ends of the axle beam, the horizontal separation between the other end (lower end) of each suspension cylinder supporting the vehicle load and the corresponding wheel The length of the arm of the moment, which is the distance, is shortened, the bending moment acting on the axle beam is reduced, and the substantial durability of the axle beam is improved.

  Further, in Patent Document 2, in addition to the configuration disclosed in Patent Document 1, one end (upper end) of each of the left and right suspension cylinders supporting the front shaft and the left and right suspension cylinders supporting the rear shaft is disposed above the vehicle body frame. It is attached to the vehicle body frame via left and right suspension cylinder mounting brackets that protrude and extend laterally, and the differential case is fixed to the vehicle body frame, and the axle as a mounting structure that allows relative displacement of the left and right drive shafts of the differential case The beam is omitted, the structure around the drive shaft is reduced in size and diameter, and the left and right drive shafts are passed through the left and right end faces of the body frame, or the structure is passed directly under the body frame. By eliminating the parts placed below the body frame, or And smaller and smaller diameter parts projecting downward from the frame, the suspension system has been proposed which is adapted reduce the overall height of the working machine.

Japanese Utility Model Publication No. 6-27447 (page 3, left column, line 44 to page 3, right column, line 10, FIG. 1) JP 2000-159481 A (paragraph 0033, paragraph 0035, FIG. 2, FIG. 3)

  However, the other ends (lower ends) of the left and right suspension cylinders are attached to the upper ends of the left and right king pins along the center axis of the steering of each wheel, and the other ends and wheels of the respective suspension cylinders that support the vehicle load. In the case of the suspension device of Patent Document 1 in which the bending moment acting on the axle beam is reduced by shortening the length of the moment arm which is the horizontal separation distance between the left and right suspension cylinders, Since the position of the upper end of the king pin that is the mounting position of the other end (lower end), that is, the upper surface of the knuckle arm or the like is higher than the axle beam, the other end (lower end) of each of the left and right suspension cylinders is connected to the left and right sides of the axle beam. The expansion and contraction stroke of the suspension cylinder is relatively short compared to the conventional suspension system attached to the end. It made there is a disadvantage.

  On the other hand, the suspension device of Patent Document 2 in which one end (upper end) of each suspension cylinder protrudes upward from the vehicle body frame and is attached to the vehicle body frame via left and right suspension cylinder mounting brackets. In this case, the attachment position of one end (upper end) of each of the suspension cylinders moves relatively upward as compared to the suspension device shown in Patent Document 1, so that each of the left and right suspension cylinders Even if the attachment position of the end (lower end) is moved to the upper end of the king pin above the axle beam, the expansion / contraction strokes of the left and right suspension cylinders can be maintained at the same level as that of the conventional suspension device.

However, the suspension device disclosed in Patent Document 2 was devised exclusively on the basis of the suspension structure of a self-propelled working machine having a total number of axles of 2, and this technology is a self-propelled type having a total number of axles of 3 or more. It is not always easy to apply to work machines.
For example, when the suspension device disclosed in Patent Document 2 is applied to a crane with a total axle number of 3 having a front shaft, an intermediate shaft, and a rear shaft, an intermediate shaft disposed at a substantially intermediate position in the front-rear direction of the body frame is used. Since the suspension cylinder mounting bracket for mounting the supporting suspension cylinder protrudes upward from the vehicle body frame, the suspension cylinder mounting bracket of the intermediate shaft interferes with the lower surface of the rotating body due to the rotation of the rotating body on the vehicle body frame. In addition, if a large clearance is set between the vehicle body frame and the revolving body in order to prevent this interference, the overall height of the work implement becomes high, resulting in a disadvantage that traveling stability is impaired.

  Therefore, even when the present invention is applied to a self-propelled working machine having a total number of axles of 3 or more and having a turning body on a vehicle body frame, it has a sufficient telescopic stroke, and the overall height of the working machine is reduced. It is an object of the present invention to provide a suspension structure for a self-propelled working machine that can be kept as low as possible and guarantee sufficient strength around a vehicle's undercarriage.

The suspension structure of the self-propelled working machine according to the present invention is a self-propelled work having a total number of three or more axles in which a revolving body is provided on a body frame and one or more intermediate shafts are arranged between a front shaft and a rear shaft. The suspension structure of the machine,
One end of each of the left and right suspension cylinders supporting the front shaft and the left and right suspension cylinders supporting the rear shaft protrudes upward from the vehicle body frame and extends laterally through the left and right suspension cylinder mounting brackets. While attached to the body frame, the other end of each of the left and right suspension cylinders is attached to the upper ends of the left and right king pins along the center axis of the steering of each wheel,
One end of each of the left and right suspension cylinders supporting the intermediate shaft is attached to the side surface of the vehicle body frame, while the other end of each of the left and right suspension cylinders is offset inward from the center axis of the steering of each wheel. It is attached to the left and right ends of the axle beam of the intermediate shaft.

The other ends (lower ends) of the left and right suspension cylinders supporting the front axle located in front of the vehicle body frame and the left and right suspension cylinders supporting the rear axle located behind the vehicle body frame are along the center axis of the steering of each wheel. Since it is attached to the upper ends of the left and right king pins, the length of the arm of the moment, which is the horizontal separation distance between the other end (lower end) of each suspension cylinder that supports the front shaft and the rear shaft and the wheel, is shortened. The bending moment acting on the front and rear axle beams can be reduced, and the substantial durability of the front and rear axle beams can be improved.
In addition, one end (upper end) of each of these suspension cylinders is attached to left and right suspension cylinder mounting brackets that protrude upward from the body frame and extend laterally, and the mounting position is relatively compared to the axle beam. Since it moves upward, the extension strokes of the left and right suspension cylinders are guaranteed.
On the other hand, one end (upper end) of each of the left and right suspension cylinders supporting the intermediate shaft arranged at a substantially intermediate position in the front-rear direction of the body frame is attached to the side surface of the body frame, and the other end of each of the left and right suspension cylinders Since the (lower end) is offset inward from the center axis of the steering of each wheel and attached to the left and right ends of the axle beam of the intermediate shaft, the structure of the suspension structure arranged at a substantially intermediate position in the longitudinal direction of the body frame The element does not protrude upward beyond the upper surface of the body frame, and even if the revolving body on the body frame rotates, the lower surface of the revolving body and the components of the suspension structure do not interfere with each other. Thus, it becomes possible to attach the revolving structure, and the overall height of the work implement can be kept low to ensure traveling stability.
Since the other end (lower end) of each of the left and right suspension cylinders supporting the intermediate shaft is attached to the left and right ends of the axle beam of the intermediate shaft, it is between the other end (lower end) of the suspension cylinder of the intermediate shaft and the wheel. The length of the arm of the moment, which is the horizontal separation distance, is relatively longer than that of the front and rear axles, but this intermediate shaft is added to support a part of the weight of the vehicle The load acting on each axis due to the addition of the intermediate shaft is relatively reduced compared to the case of the biaxial self-propelled working machine, so the bending moment acting on the axle beam of the intermediate shaft There is no problem in the durability of the axle beam.
And, by installing this third and subsequent intermediate shafts, it is possible to cope with the increase in weight caused by the enlargement of suspended loads and loads that are handled by self-propelled working machines such as crane trucks. Can do.

  Desirably, the axle weight acting on the intermediate shaft is set to be lighter than the axle weight acting on the front shaft and the axle weight acting on the rear shaft.

  As already mentioned, the length of the arm of the moment, which is the horizontal separation distance between the other end (lower end) of the suspension cylinder of the intermediate shaft and the wheel, is longer than that of the front and rear shafts. By setting the axle weight acting on the axle lighter than the axle weight acting on the front axle and the axle weight acting on the rear axle, the bending moment acting on the axle beam of the intermediate axis can be set to the same range as the front axle and rear axle. Can fit. (On the other hand, the moment arm becomes longer, but the applied load is reduced.)

For mounting the intermediate shaft, for example,
With the vehicle body frame having a structure with a top plate covering its upper surface and left and right side plates covering its side surfaces,
Extending the top plate to the side beyond the left and right side plates at the attachment point at one end of each of the left and right suspension cylinders supporting the intermediate shaft to form a suspension cylinder mounting portion,
The one end of each of the left and right suspension cylinders supporting the intermediate shaft has its upper end surface in contact with the lower surface of the suspension cylinder mounting portion, its inner end surface in contact with the left and right side plates, and its outer end surface in the aforementioned A structure of attaching to the side surface of the vehicle body frame via an intermediate shaft suspension cylinder mounting bracket having a size that does not protrude sideways from the top plate can be applied.

The suspension cylinder mounting bracket for the intermediate shaft is fixed to the vehicle body frame in contact with both the lower surface of the suspension cylinder mounting portion formed integrally with the top plate of the vehicle body frame and the side plate of the vehicle body frame. The suspension cylinder can be firmly attached to both sides of the vehicle body frame.
Since the suspension cylinder mounting bracket for the intermediate shaft located on the lower surface of the suspension cylinder mounting part, which is a part of the top plate, does not protrude upward beyond the top plate of the body frame, attach the revolving body in close contact with the body frame Therefore, the overall height of the work implement can be kept low to ensure running stability.

  Furthermore, the left and right suspension cylinders that support the front shaft, the left and right suspension cylinders that support the rear shaft, and the left and right suspension cylinders that support the intermediate shaft may be unified with the same standard product.

  As already described, the other end (lower end) of each of the left and right suspension cylinders supporting the front shaft and the rear shaft is attached to the upper end of the king pin at a position higher than the axle beam, that is, the upper surface of the knuckle arm, etc. The other end (lower end) of each of the left and right suspension cylinders that support the upper and lower ends of the kingpin, that is, the left and right ends of the axle beam at a position lower than the upper surface of the knuckle arm, etc. One end (upper end) of each of the left and right suspension cylinders that support the shaft is attached to the vehicle body frame via left and right suspension cylinder mounting brackets that protrude upward and extend laterally from the vehicle body frame, while the left and right suspension cylinders that support the intermediate shaft One end (upper end) of each suspension cylinder is attached to the side of the body frame Therefore, it is possible to make the specifications related to the length of the suspension cylinder independent of the front shaft, the intermediate shaft, and the rear shaft, and the same specification makes it easy to manage the parts in the production process. In addition, it is possible to prevent misassembly in the assembly process.

The suspension structure of the self-propelled working machine according to the present invention includes the other end of each of the left and right suspension cylinders supporting the front shaft positioned in front of the vehicle body frame and the left and right suspension cylinders supporting the rear shaft positioned in the rear of the vehicle body frame. Since the lower end is attached to the upper end of the left and right king pins along the center axis of the steering of each wheel, horizontal separation between the other end (lower end) of each suspension cylinder that supports the front and rear shafts and the wheel The length of the moment moment arm is shortened, the bending moment acting on the front and rear axle beams is reduced, and the substantial durability of the front and rear axle beams can be improved. it can.
In addition, one end (upper end) of each of these suspension cylinders is attached to left and right suspension cylinder mounting brackets that protrude upward from the body frame and extend laterally, and the mounting position is relatively compared to the axle beam. Since it moves upward, the extension strokes of the left and right suspension cylinders are guaranteed.
On the other hand, one end (upper end) of each of the left and right suspension cylinders supporting the intermediate shaft arranged at a substantially intermediate position in the front-rear direction of the body frame is attached to the side surface of the body frame, and the other end of each of the left and right suspension cylinders Since the (lower end) is offset inward from the center axis of the steering of each wheel and attached to the left and right ends of the axle beam of the intermediate shaft, the structure of the suspension structure arranged at a substantially intermediate position in the longitudinal direction of the body frame The element does not protrude upward beyond the upper surface of the body frame, and even if the revolving body on the body frame rotates, the lower surface of the revolving body and the components of the suspension structure do not interfere with each other. Thus, it becomes possible to attach the revolving structure, and the overall height of the work implement can be kept low to ensure traveling stability.
Since the other end (lower end) of each of the left and right suspension cylinders supporting the intermediate shaft is attached to the left and right ends of the axle beam of the intermediate shaft, it is between the other end (lower end) of the suspension cylinder of the intermediate shaft and the wheel. The length of the arm of the moment, which is the horizontal separation distance, is longer than that of the front and rear axles, but this intermediate shaft is added to support a part of the weight of the vehicle. The load acting on each axis due to the extension of the shaft is relatively reduced compared to the case of the biaxial self-propelled working machine. Therefore, the axle beam of the intermediate shaft is affected by the bending moment acting on the axle beam of the intermediate shaft. There is no problem in durability.
By installing the third and subsequent intermediate shafts, it is possible to cope with an increase in weight due to an increase in the size of a suspended load or a load to be handled by a self-propelled working machine such as a crane truck.

  In addition, by setting the axle weight acting on the intermediate shaft lighter than the axle weight acting on the front axle and the axle weight acting on the rear axle, the suspension between the other end (lower end) of the suspension cylinder of the intermediate shaft and the wheel Even if the length of the arm of the moment, which is the horizontal separation distance, is longer than that of the front and rear axes, the bending moment acting on the axle beam of the intermediate axis should be within the same range as the front and rear axes. Can do. (On the other hand, the moment arm becomes longer, but the applied load is reduced.)

For the attachment of the intermediate shaft, for example, the top plate of the vehicle body frame that extends laterally beyond the left and right side plates at the one end (upper end) of each of the left and right suspension cylinders that support the intermediate shaft is used as the suspension cylinder mounting portion. One end (upper end) of each of the left and right suspension cylinders supporting the intermediate shaft has its upper end surface in contact with the lower surface of the suspension cylinder mounting portion and its inner end surface in contact with the left and right side plates of the vehicle body frame. A structure in which the outer end surface is attached to the side surface of the vehicle body frame via a suspension cylinder mounting bracket for an intermediate shaft that does not protrude sideways from the top plate can be applied. By applying such a structure, the upper surface of the vehicle body frame can be Beyond this, it is possible to reliably prevent the components of the suspension structure from protruding upward.
Further, the suspension cylinder mounting bracket for the intermediate shaft is fixed to the vehicle body frame by contacting both the lower surface of the suspension cylinder mounting portion formed integrally with the top plate of the vehicle body frame and the side plate of the vehicle body frame, so that the intermediate shaft is supported. The left and right suspension cylinders can be firmly attached to both sides of the body frame.

  In this way, the other end (lower end) of each of the left and right suspension cylinders supporting the front and rear shafts is attached to the upper end of the king pin located higher than the axle beam, while the left and right suspension cylinders supporting the intermediate shaft Each other end (lower end) is attached to the left and right end portions of the axle beam at a position lower than the upper end portion of the king pin, but one end (upper end) of each of the left and right suspension cylinders supporting the front shaft and the rear shaft. ) Is attached to the vehicle body frame via left and right suspension cylinder mounting brackets that protrude upward from the vehicle body frame and extend laterally, while one end (upper end) of each of the left and right suspension cylinders supporting the intermediate shaft is the vehicle body frame The specifications related to the length of the suspension cylinder Front axle, the intermediate shaft, is capable of identification with through the rear shaft, the same of specification, been easier parts management in the production process, also prevents set differences in the assembly process.

It is the side view which showed the external appearance of the crane vehicle of one Embodiment to which the suspension apparatus of the working machine in this invention was applied. It is the perspective view which showed the surrounding structure of the vehicle body frame of the crane vehicle in the same embodiment. It is the bottom view which showed the vehicle body frame of the crane vehicle in the same embodiment from the lower surface side. FIG. 4 is a front view showing a suspension structure of each shaft attached to the body frame of the crane vehicle in the embodiment, and FIG. 4A shows a peripheral structure of the front shaft for attaching the left and right front wheels to the body frame. FIG. 4B is a front view showing the peripheral structure of the intermediate shaft for attaching the left and right intermediate wheels to the vehicle body frame, and FIG. 4C is the rear shaft for attaching the left and right rear wheels to the vehicle body frame. It is the front view which showed the surrounding structure.

  Next, an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a side view showing the appearance of a crane truck according to an embodiment to which the suspension device of the present invention is applied.
As shown in FIG. 1, a crane 1 of this embodiment includes a vehicle body frame 2 on which an engine, a transmission, and the like are disposed, a revolving body 3 that is installed on the vehicle body frame 2 so as to be able to turn, and a revolving body 3. A multi-stage boom 4 pivoted on the base and raised in a vertical plane, and a working / operating cabin 5 fixed to the revolving body 3 are also provided. An outrigger 6 is provided.
As shown in FIG. 1, the crane vehicle 1 of this embodiment is a three-axis six-wheel crane vehicle, and includes left and right front wheels 7 and 7, left and right intermediate wheels 8 and 8, and left and right rear wheels 9 and 9. .

FIG. 2 is a perspective view showing the peripheral structure of the body frame 2 in the crane vehicle 1 of FIG. 1, and FIG. 3 is a bottom view showing the body frame 2 from the lower surface side.
4 is a front view showing the suspension structure of each shaft attached to the vehicle body frame 2. FIG. 4A is a front shaft for attaching the left and right front wheels 7, 7 to the vehicle body frame 2. FIG. 4 (b) is a front view showing the peripheral structure of the intermediate shaft for attaching the left and right intermediate wheels 8, 8 to the body frame 2, and FIG. 4 (c) is the body frame 2. It is the front view which showed the periphery structure of the rear axis | shaft for attaching left and right rear-wheels 9,9.

As shown in FIG. 2, the main part of the vehicle body frame 2 in the crane vehicle 1 is constituted by a top plate 10 that covers the top surface thereof, and left and right side plates 11 and 11 that cover the side surfaces thereof.
A circular revolving body installation hole 12 for rotatably mounting the revolving body 3 is provided in a substantially central portion of the top plate 10, while a power train for installing an engine, a transmission, or the like is provided in the rear part of the top plate 10. A gap for forming the installation portion 13 is defined long in the front-rear direction.
Since the installation of the engine, transmission, and the like installed in the powertrain installation unit 13 is known, it will not be described here.
Further, the lower surface side of the vehicle body frame 2 is covered with a bottom plate 14 which is thinned in place as shown in FIG. 3, and has a strong stress skin structure by the top plate 10, the left and right side plates 11, 11 and the bottom plate 14. A vehicle body frame 2 is formed.

As shown in FIG. 4 (a), the front shaft 15 that supports the front wheels 7 and 7 is constituted by an axle beam 16 including a differential case and knuckle arms (wheel support portions) 17 and 17 provided on the left and right sides thereof. The left and right knuckle arms 17 and 17 are steered by left and right steering hydraulic cylinders 19 and 19 around a kingpin 18 and 18 that is a central axis of steering.
The movement of the axle beam 16 is allowed only in the vertical direction by the torque rod 20 and the lateral rod 41, and the steering angles of the left and right knuckle arms 17 and 17 are synchronized by the tie rods 21 connecting them.
Then, one end (upper end) of each of the left and right suspension cylinders 22 and 22 supporting the front shaft 7 protrudes upward from the upper surface of the top plate 10 of the vehicle body frame 2 as shown in FIGS. 2 and 4A. The left and right suspension cylinders 23 and 23 are pivotally attached to the vehicle body frame 2 via the left and right suspension cylinder mounting brackets 23 and 23, respectively. 7 is pivotally attached to the upper ends of the left and right king pins 18 along the central axis of the 7 steering.
As shown in FIG. 4A, the pivot position of one end (upper end) of each of the left and right suspension cylinders 22 and 22 is equal to or slightly higher than the height of the top surface of the top plate 10.

The magnitude of the bending moment acting on the axle beam 16 is set such that the front shaft 15 has a horizontal separation distance D1 (the length of the moment arm) between the other end (lower end) of the suspension cylinder 22 and the front wheel 7 corresponding thereto. It is a value obtained by multiplying 1/2 of the axial weight acting on.
Therefore, the mounting position of the other end (lower end) of the suspension cylinder 22 is set to the king pin 18 positioned outside the axle beam 16, and the value of the horizontal separation distance D1 is reduced, so that the suspension cylinder 22 is disposed at the end of the axle beam 16. Compared with the case where the other end (lower end) is attached, the bending moment acting on the axle beam 16 can be reduced and the substantial durability of the axle beam 16 can be improved.
By setting the mounting position of the other end (lower end) of the suspension cylinder 22 to the king pin 18, the other position of the suspension cylinder 22 is compared with the case where the other end (lower end) of the suspension cylinder 22 is mounted on the upper surface of the end of the axle beam 16. Although the end (lower end) mounting position moves upward, the suspension cylinder mounting bracket 23 side that regulates the mounting position of one end (upper end) of the suspension cylinder 22 is also higher than the upper surface of the top plate 10 of the vehicle body frame 2. Since it is moved, the expansion / contraction stroke of the suspension cylinder 22 is guaranteed.

Further, as shown in FIG. 4 (c), the rear shaft 24 that supports the rear wheels 9, 9 includes an axle beam 25 including a differential case, knuckle arms (wheel support portions) 26, 26 provided on the left and right sides thereof, and the like. The left and right knuckle arms 26, 26 are steered around king pins 27, 27, which are the central axes of steering, and the steering angles of the left and right knuckle arms 26, 26 are tie rods 28 connecting them. To be synchronized.
As described above, the movement of the axle beam 25 is allowed only in the vertical direction by the torque rod 42.
Then, one end (upper end) of each of the left and right suspension cylinders 29, 29 supporting the rear shaft 24 protrudes above the upper surface of the top plate 10 of the vehicle body frame 2 as shown in FIGS. 2 and 4C. The left and right suspension cylinder mounting brackets 30 and 30 are pivotally attached to the vehicle body frame 2 while the other ends (lower ends) of the left and right suspension cylinders 29 and 29 are connected to the rear sides. It is pivotally attached to the upper ends of the left and right king pins 27, 27 along the center axis of the steering of the wheels 9, 9.
As shown in FIG. 4 (c), the pivot position of one end (upper end) of each of the left and right suspension cylinders 29, 29 is equal to or slightly higher than the height of the top surface of the top plate 10, and the front shaft This is equivalent to the height of the pivot position of one end (upper end) of each of the 15 suspension cylinders 22, 22.

The magnitude of the bending moment acting on the axle beam 25 depends on the horizontal separation distance D1 ′ (the length of the arm of the moment) between the other end (lower end) of the suspension cylinder 29 and the rear wheel 9 corresponding thereto. It is a value obtained by multiplying 1/2 of the shaft weight acting on the shaft 24.
Accordingly, the mounting position of the other end (lower end) of the suspension cylinder 29 is the king pin 27 positioned outside the axle beam 25, and the value of the horizontal separation distance D1 ′ is reduced, so that the suspension cylinder 29 is placed at the end of the axle beam 25. Compared with the case where the other end (lower end) is attached, the bending moment acting on the axle beam 25 can be reduced and the substantial durability of the axle beam 25 can be improved.
By setting the mounting position of the other end (lower end) of the suspension cylinder 29 to the king pin 27, the other position of the suspension cylinder 29 is compared with the case where the other end (lower end) of the suspension cylinder 29 is mounted on the upper surface of the end of the axle beam 25. The mounting position of the end (lower end) moves upward, but the suspension cylinder mounting bracket 30 side that regulates the mounting position of one end (upper end) of the suspension cylinder 29 is also higher than the upper surface of the top plate 10 of the vehicle body frame 2. Since it is moved, the expansion / contraction stroke of the suspension cylinder 29 is guaranteed.

On the other hand, as shown in FIG. 4B, the intermediate shaft 31 that supports the intermediate wheels 8 and 8 includes an axle beam 32 and knuckle arms (wheel support portions) 33 and 33 provided on the left and right sides thereof. The left and right knuckle arms 33 and 33 are steered around king pins 34 and 34 that are the central axes of the steering, and the steering angles of the left and right knuckle arms 33 and 33 are determined by tie rods 35 connecting them. Synchronized.
Further, the movement of the axle beam 32 is allowed only in the vertical direction by the torque rod 36 and the lateral rod 37.
As shown in FIG. 3, the top plate 10 of the vehicle body frame 2 extends beyond the left and right side plates 11, 11 at at least one end (upper end) of the left and right suspension cylinders 38, 38 that support the intermediate shaft 31. Extending laterally, this portion forms an overhanging portion that becomes the suspension cylinder mounting portion 39, 39.
Then, one end (upper end) of each of the left and right suspension cylinders 38, 38 supporting the intermediate shaft 31 has its upper end surface 40a abutting against the lower surface of the suspension cylinder mounting portion 39, as shown in FIG. In addition, the side surface of the vehicle body frame 2 through the intermediate shaft suspension cylinder mounting brackets 40, 40 whose inner end surface 40b abuts against the side plate 11 and whose outer end surface 40c does not protrude sideways from the top plate 10. 11 and 11 are attached.
In this way, the suspension cylinder mounting bracket 40 for the intermediate shaft is attached to the vehicle body frame 2 by contacting both the lower surface of the suspension cylinder mounting portion 39 formed integrally with the top plate 10 of the vehicle body frame 2 and the side plate 11 of the vehicle body frame 2. By fixing by means of welding or the like, one end (upper end) of the left and right suspension cylinders 38, 38 supporting the intermediate shaft 31 located near the center in the longitudinal direction of the body frame 2 is firmly attached to both sides of the body frame 2. Can do.
In addition, since the suspension cylinders 38 and 38 and the intermediate shaft suspension cylinder mounting bracket 40 which are a kind of components of the suspension structure do not protrude upward beyond the top plate 10 of the vehicle body frame 2, Interference between the components of the suspension structure and the revolving structure 3 is eliminated, the revolving structure 3 can be attached in close contact with the body frame 2, and the overall height of the crane vehicle 1 is kept low to ensure traveling stability. can do.
As shown in FIG. 4B, the other ends (lower ends) of the left and right suspension cylinders 38, 38 are inward from the king pins 34, 34 that are the central axes of the steering of the intermediate wheels 8, 8. It is offset and attached to the upper surface side of the left and right end portions of the axle beam 32 of the intermediate shaft 31.
As shown in FIG. 4 (b), the pivot position of one end (upper end) of each of the left and right suspension cylinders 38, 38 is the lower surface side of the top plate 10, and accordingly, each of the suspension cylinders 22, 22 of the front shaft 15. The height of the mounting position is lower than the pivot position of one end (upper end) of each of the suspension cylinders 29 and 29 and the pivot position of one end (upper end) of each of the suspension cylinders 29 and 29 of the rear shaft 24.

  Further, the shaft weight acting on the intermediate shaft 31 is designed to be lighter than the shaft weight acting on the front shaft 15 and the shaft weight acting on the rear shaft 24.

The magnitude of the bending moment acting on the axle beam 32 is such that the horizontal axis distance D2 (the length of the moment arm) between the other end (lower end) of the suspension cylinder 38 and the rear wheel 8 corresponding thereto is an intermediate axis. It is a value obtained by multiplying 1/2 of the axial weight acting on the shaft 31.
With respect to the intermediate shaft 31, since the attachment position of the other end (lower end) of the suspension cylinder 38 is the end of the axle beam 32 located inside the king pin 34, the horizontal separation distance D2 that is the length of the arm of moment is It is longer than D1 in the case of the front shaft 15 and D1 ′ in the case of the rear shaft 24. However, since the axle weight acting on the intermediate shaft 31 is designed to be lighter than the axle weight acting on the front shaft 15 and the axle weight acting on the rear shaft 24, it acts on the axle beam 32 of the intermediate shaft 31. For example, the bending moment acting on the axle beam 32 can be kept in the same range as that of the front shaft 15 and the rear shaft 24.

  In this way, by installing the third intermediate shaft 31 and the intermediate wheels 8 and 8 in addition to the front shaft 15 and the rear shaft 24, the crane vehicle 1 can handle large loads. It becomes possible to cope with the increase in the weight of the vehicle body accompanying the increase in the size.

The configuration of the power transmission system and the steering system is already known and will not be described in particular. However, in the crane 1 in this embodiment, the front wheels 7 and 7 attached to the front axle 15 and the rear axle 24 are attached. Four wheels 9 and 9 function as drive wheels, and the front wheels 7 and 7 attached to the front shaft 15, the intermediate wheels 8 and 8 attached to the intermediate shaft 31, and the rear wheel 9 attached to the rear shaft 24. , 9 function as steering wheels.
During traveling, it is usually possible to transmit the driving force only to the front shaft 15 and to transmit the driving force divided at a certain ratio to both the front shaft 15 and the rear shaft 24. .

In this embodiment, the front shaft 15 and the rear shaft 24 are both suspended from the suspension cylinders 22 and 29 via suspension cylinder mounting brackets 23 and 30 that protrude upward from the body frame 2 and extend laterally. One end (upper end) is attached to the vehicle body frame 2, and the other end (lower end) of each of the suspension cylinders 22 and 29 is attached to the upper end portions of the king pins 18 and 26. The distance between the pivot points located is equal to the distance between the pivot points located at both ends of the suspension cylinder 29.
Accordingly, the suspension cylinder 22 of the front shaft 15 and the suspension cylinder 29 of the rear shaft 24 can use the same specification and are compatible.

On the other hand, with respect to the suspension cylinder 38 of the intermediate shaft 31, the other end (lower end) is attached to the upper surface of the end of the axle beam 32 at a position lower than the upper end of the king pin 34. Since one end (upper end) is also attached to the side surface of the vehicle body frame 2 at a position lower than the upper surface of the top plate 10, as a result, the distance between the pivot points located at both ends of the suspension cylinder 38 and the suspension The distances between the pivot points located at both ends of the cylinders 22 and 29 are equal, and the suspension cylinder 38 of the intermediate shaft 31, the suspension cylinder 22 of the front shaft 15, and the suspension cylinder 29 of the rear shaft 24 have the same specifications. Can be used.
As described above, by making the specifications related to the lengths of the suspension cylinders 22, 29, and 38, that is, the separation distances between the pivot points, the suspension cylinders having the same specifications common to the respective shafts can be used. , Parts management in the production process is facilitated.
In addition, since these specifications are the same, as a result, there is no problem even if each of the suspension cylinders 22, 29, 38 is attached to any of the front shaft 15, the intermediate shaft 31, and the rear shaft 24. In addition, it is possible to prevent the suspension cylinder from being assembled in the assembling process.

In the above embodiment, the case where the suspension device of the present invention is applied to the three-shaft and six-wheeled crane vehicle 1 has been described as an example. However, the suspension device of the present invention is also applicable to a crane vehicle having a total number of axles exceeding three. it can.
In the case of a crane truck with a total number of axles exceeding 3, the frontmost axis of the crane truck is the front axle, the rearmost axis is the rear axle, and all other axes are It is an intermediate shaft.
Further, in a crane vehicle having a total number of axles of 3 or more, which shaft is used as a drive wheel and which shaft is used as a steering train are design issues.

  The present invention can be applied to a self-propelled working machine having a total number of axles of 3 or more, including a crane car and the like, and a turning body on a body frame.

DESCRIPTION OF SYMBOLS 1 Crane vehicle 2 Body frame 3 Revolving body 4 Boom 5 Cabin 6 Outrigger 7 Front wheel 8 Intermediate wheel 9 Rear wheel 10 Top plate 11 Side plate 12 Revolving body installation hole 13 Power train installation part 14 Bottom plate 15 Front shaft 16 Axle beam 17 Knuckle arm (wheel) Support part)
18 King pin 19 Steering hydraulic cylinder 20 Torque rod 21 Tie rod 22 Suspension cylinder 23 Suspension cylinder mounting bracket 24 Rear axle 25 Axle beam 26 Knuckle arm (wheel support part)
27 King pin 28 Tie rod 29 Suspension cylinder 30 Suspension cylinder mounting bracket 31 Intermediate shaft 32 Axle beam 33 Knuckle arm (wheel support part)
34 King Pin 35 Tie Rod 36 Torque Rod 37 Lateral Rod 38 Suspension Cylinder 39 Suspension Cylinder Mounting Portion (Projection of Top Plate)
40 Intermediate shaft suspension cylinder mounting bracket 40a Upper end surface 40b of intermediate shaft suspension cylinder mounting bracket Inner end surface 40c of intermediate shaft suspension cylinder mounting bracket Outer end surface 41 of intermediate shaft suspension cylinder mounting bracket Lateral rod 42 Torque rod

Claims (4)

A suspension structure for a self-propelled working machine having a total number of three or more axles in which a revolving body is provided on a body frame and one or more intermediate shafts are disposed between a front shaft and a rear shaft,
One end of each of the left and right suspension cylinders supporting the front shaft and the left and right suspension cylinders supporting the rear shaft protrudes upward from the vehicle body frame and extends laterally through the left and right suspension cylinder mounting brackets. While attached to the body frame, the other end of each of the left and right suspension cylinders is attached to the upper ends of the left and right king pins along the center axis of the steering of each wheel,
One end of each of the left and right suspension cylinders supporting the intermediate shaft is attached to the side surface of the vehicle body frame, while the other end of each of the left and right suspension cylinders is offset inward from the center axis of the steering of each wheel. A suspension structure for a self-propelled working machine, wherein the suspension structure is attached to left and right ends of the axle beam of the intermediate shaft.   The suspension structure for a self-propelled working machine according to claim 1, wherein a shaft weight acting on the intermediate shaft is lighter than a shaft weight acting on the front shaft and a shaft weight acting on the rear shaft. The vehicle body frame includes a top plate covering its upper surface, and left and right side plates covering its side surfaces,
The top plate extends laterally beyond the left and right side plates at a mounting position of one end of each of the left and right suspension cylinders that support the intermediate shaft to form a suspension cylinder mounting portion.
The one end of each of the left and right suspension cylinders supporting the intermediate shaft has its upper end surface in contact with the lower surface of the suspension cylinder mounting portion, its inner end surface in contact with the left and right side plates, and its outer end surface 3. The self-propelled working machine according to claim 1, wherein the self-propelled working machine is attached to a side surface of the vehicle body frame via a suspension cylinder mounting bracket for an intermediate shaft that does not protrude sideways from the top plate. Suspension structure.   The left and right suspension cylinders supporting the front shaft, the left and right suspension cylinders supporting the rear shaft, and the left and right suspension cylinders supporting the intermediate shaft are of the same standard product. The suspension structure of the self-propelled working machine according to any one of 3.

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