TITLE OF THE INVENTION CAB SUSPENSION APPARATUS FOR A CONSTRUCTION MACHINE

TECHNICAL FIELD

The present disclosure relates to a cab suspension apparatus for a construction machine and more particularly, a cab suspension apparatus for a construction machine in which a load of the cab can be supported and vibrations transferred from a machine frame to a cab is absorbed by an improved linkage mechanism.

BACKGROUND OF THE INVENTION

Generally, the construction machine comprises a cab mounted on a machine frame. Particularly, the hauler or the wheel loader which includes the cab is operated under the unfavorable condition rolling over bumpy grounds. An operator driving such construction machines is exposed to the severe vibration depending on the ground condition.

Fig. 1 is the schematic view of the conventional hauler with a cab mounted on a machine chassis, and Fig. 2 is the detailed view o the mounting part of the hauler cab illustrated in Fig. 1. A cab 1 is mounted on a machine frame 2. In an exemplary application as shown in

Fig. 1 , the cab 2 may be mounted on the chassis. In general, the machine frame 2 formed at the front part may be connected with the rear part of the vehicle chassis (not shown in figure). Further, the machine frame 2 formed the front part may be articulated relatively to the rear part via a joint connection.

The cab 1 has a dimension designed for the controllability, and a bottom plate 4 of the cab 1 is fixed on the machine frame 2 by the steel cab posts 3, Further, the bottom plate 4 of the cab 1 is carried or supported by means of the damping apparatus where a rubber damper 5, a rubber disc 6, a washer 7 and a screw 8 are included, thereby reducing vibrations transferred to the cab 1.

However, the vibrations can be generated depending on the ground condition during travelling on a ground, and it can be transferred to the cab through the machine frame or the vehicle chassis, which is a primary cause for the inferior ride comfort and consequently causes the diseases such as backache or headache.

In order to reduce vibrations, the suspension system of McPherson strut is well known, which uses Telescope Damper and Coil Spring. However, when the system is applied for the construction machine, it has disadvantage of restricting the suspension performance under the severe vibrating conditions of the ground and a weight loaded with the cab.

The patent application of "Cab suspension linkage system" is disclosed in US 7,744,149 where is provided a linkage assembly comprising a first fore-aft linkage and a second fore-aft linkage for restraining movement of the first or second chassis sections, a lateral linkage for restraining rotational movement of the cab, and a dampener for damping motion between the cab and the chassis.

However, this patent also has the disadvantages of the structural complexity due to the scheme of "Watts linkages".

SUMMARY OF THE INVENTION

Accordingly, the present disclosure has been made to solve the aforementioned problems occurring in the related art, and it is an object of the present disclosure to provide an improved suspension apparatus for the construction machine. The present disclosure provides a suspension apparatus for the construction machine in which a cab is movably supported by tilting the connecting arms linked to the connecting rods, and thus vibrations applied to the machine frame are reduced.

To achieve the above object, according to one aspect of the present disclosure, there provides a suspension apparatus for a construction machine comprising:

a cab;

a pair of support chassis mounted on a machine frame in parallel to each other, each of the support chassis including a body fixed on the machine frame, a pair of upper wings and a pair of lower wings extending in opposite directions from the body, respectively; a pair of connecting arms configured to locate between the upper wing and a bottom plate of the cab, respectively, each of the connecting arms including an upper joint, an inner arm and an outer arm spaced apart from each other wherein the inner arms is tiltably connected to the upper wing;

a pair of connecting rods, each of the connecting rods configured to rotatably connect the upper joint with the bottom plate of the cab; and

a pair of damping members, each of the damping members connected between the outer arm and the lower wing.

According to the present disclosure, preferably, the body of the support chassis is configured to mount on the machine frame in a width direction of the cab

According to the present disclosure, preferably, each of the connecting arms is configured to form Y-shaped linkage. According to the present disclosure, preferably, the cab comprises a plurality of mounting blocks formed at the bottom plate of the cab so that the connecting rods are coupled to the mounting blocks, respectively.

According to the present disclosure, preferably, each of the connecting rods includes an anti-corrosion member. According to the present disclosure, preferably, each of the damping members includes a cylinder that is rotatably installed on the lower wings.

According to the present disclosure, each of the damping members comprises a gas or hydraulic spring.

According to the present disclosure, the body of the support chassis can be configured to mount on the machine frame in a forward-backward direction of the cab.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram showing the cab installed on the machine chassis of the conventional hauler.

Fig. 2 is a detailed view of the mounting part of the cab illustrated in Fig, 1.

Fig. 3 is an exploded perspective view of a cab suspension apparatus for a construction machine according to an embodiment of the present disclosure.

Fig. 4a is a side view of a connecting arm for a cab suspension apparatus according to an embodiment of the present disclosure.

Fig. 4b is a side view of a connecting arm for a cab suspension apparatus according to another embodiment of the present disclosure. Fig. 5 is a side view of a linkage for a cab suspension apparatus according to an embodiment of the present disclosure.

Fig. 6 is a side view of a linkage assembled for a cab suspension apparatus in a balancing state according to an embodiment of the present disclosure.

Fig. 7 is a side view of the linkage shown in the Fig. 6 in a state where a load to the right is generated due to vibrations.

Fig. 8 is a side view of the linkage shown in the Fig. 6 in a state where a load to the left is generated due to vibrations.

Fig. 9 is a perspective view of a cab suspension apparatus in a state where a cab is suspended when a load owing to vibrations is dynamically applied tlixough each of the support chassis. Fig. 10 is a schematic diagram of a hauler equipped with a cab suspension apparatus for according to an embodiment of the present disclosure,

Fig, 11 is a schematic diagram of a wheel loader equipped with a cab suspension apparatus for according to another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. While the present disclosure will be described in conjunction with the following embodiments, it will be understood that they are not intended to limit the present disclosure to these embodiments alone. On the contrary, the present disclosure is intended to cover alternatives, modifications, and equivalents which may be included within the spirit and scope of the present disclosure as defined by the appended claims. Furthermore, in the following detailed description of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, embodiments of the present disclosure may be practiced without these specific details. As used herein, the term "X-axis direction" should be construed as meaning a forward-backward direction of a cab or a longitudinal direction of a construction machine and the term "Y-axis direction" should be construed as meaning a width direction or a right-left direction associated with a cab or a construction machine. Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

Fig, 3 is an exploded perspective view of a cab suspension apparatus for a construction machine according to an embodiment of the present disclosure.

Referring to Fig. 3, a suspension apparatus according to an embodiment of the present disclosure comprises a cab 1 where an operator is stayed for controlling the construction machine and a pair of support chassis 10 which is mounted on a machine frame 2. It is also appreciated that the support chassis 10 can be an integral part of the machine frame 2. Preferably, a suspension apparatus according to an embodiment of the present disclosure comprises a pair of support chassis 10, in parallel to each other, each of the support chassis 10a, 10b including a body 15, a pair of upper wings 13, 14 and a pair of lower wings 1 1 , 12 extending in opposite directions from the body 15, respectively.

The body 15 of the support chassis 10a, 10b is fixed on the machine frame 2. Alternatively, the body 15 of the support chassis 10a, 10b may be detachably installed on the machine frame 2 in a manner that the body is fixed by bolting or coupling with assembling fixtures.

At least one of the support chassis 10a, 10b are configured to mount on the machine frame in a width direction of the cab, respectively. By this configuration, the cap 1 can be moved in any direction depending on the direction of the force causing vibration.

Preferably, the body 15 is configured to mount on the machine frame in a width direction of the cab. Their locations, strengths or stiffness for the support chassis 10a, 10b can be variously changed depending on frequency of vibrations or amplitude of vibrations applied to the cab 1.

Numerical references 16, 17 are mounting holes for a joint connection, respectively, such as a pivot shaft 26.

Fig. 4a is a side view of a connecting arm for a cab suspension apparatus according to an embodiment of the present disclosure. Fig. 4b is a side view of a connecting arm for a cab suspension apparatus according to another embodiment of the present disclosure. Referring to Fig. 4a, a suspension apparatus according to an embodiment of the present disclosure comprises a pair of connecting arms 20 configured to locate between the upper wing 13, 14 and a bottom plate 4 of the cab 1 , respectively. Each of the connecting arms 20 includes an upper joint 21 , an inner arm 22a and an outer arm 22b spaced apart from each other wherein the inner arm is tiltably connected to the upper wing 13, 14. Referring to Fig. 4b, it is understood that the triangular shape of the connecting arms 20 can include both symmetric and asymmetric triangles. Also, the upper joint 21 can be any position which is in the middle of the inner arm 22a and the outer arm 22b.

A plurality of mounting holes 23, 24 and 25 are formed in the center section 21 , the inner arm 22a and the outer arm 22b, respectively. The mounting holes 23, 24 and 25 are for a joint connection, respectively, such as a pivot shaft 26.

The inner arm 22a and the outer arm 22b may be integrally formed. Further, the connecting arms are structurally formed in a manner of an acute-angled triangle.

Preferably, each of the connecting arms 20 is configured to form Y-shaped linkage, such as a wishbone that includes an inner arm 22a and an outer arm 22b.

Fig. 5 is a side view of a linkage for a cab suspension apparatus according to an embodiment of the present disclosure.

A suspension apparatus according to an embodiment of the present disclosure comprises a pair of connecting rods 32. Each of the connecting rods 32 is configured to rotatably connect the upper joint 21 with the bottom plate 4 of the cab 1 through the mounting holes 17. Each of the connecting rods 32 includes an anti-corrosion member for preventing the corrosion or contamination, such as a rubber. Alternatively, a steel protection is covered on the connecting rods 32.

The cab 1 comprises a plurality of mounting blocks 30 formed at the bottom plate 4 of the cab I so that the connecting rods 32 are coupled or engaged at an inner end with the mounting blocks 30, respectively. A connecting rod 34 may be arranged with the mounting blocks 30, respectively, along Y-direction. The connecting rod 32 may be provided with two separate rods. Although particularly depicted in the drawings, it should be understood that the connecting rod 32 is configured to be divided in a manner that a joint connection or a coupling connection is implemented between two separate rods. Preferably, if the two rods are configured to form a connecting rod by the coupling connection, suspension can work along an axis of the connecting rod. Their locations, strengths or stiffness for the connecting rods 32 can be variously changed depending on frequency of vibrations, amplitude of vibrations applied to the cab 1 or a load that is generated to the cab 1 , depending on vibrations.

According to an embodiment of the present disclosure, a suspension apparatus comprises a pair of damping members 40. Preferably, each of the damping members 40 is connected between the outer arm 22b and the lower wing 11, 12, respectively. According to an embodiment of the present disclosure, each of the damping members 40 includes a cylinder 41 that is rotatably installed on the lower wings 1 1 , 12. The cylinder 41 is an air cylinder powered by a compressor, a hydraulic cylinder powered by a hydraulic resource (not shown in the drawings). Preferably, each of the damping members 40 comprises a gas or hydraulic spring.

Fig. 6 is a side view of a linkage assembled for a cab suspension apparatus in a balancing state according to an embodiment of the present disclosure.

Referring to Fig. 6, if vibrations are not occurred, the connecting arms 20 linked or jointed by the connecting rods 32 are maintained in a balancing state where a tilting of the connecting arms 20 or a rotation of the cab 1 is not generated.

Fig. 7 is a side view of the linkage shown in the Fig. 6 in a state where a load to the right is generated due to vibrations. Fig. 8 is a side view of the linkage shown in the Fig. 6 in a state where a load to the left is generated due to vibrations. According to an embodiment of the present disclosure, when vibrations are occurred during a load to the right or the left is generated, the cab 1 can be supported by a rotation and a translation on the machine frame 2. More specifically, referring to Fig. 7, if a load is forced to the right of the cab 1 , the damping member 40 installed in the lower wing 11 at the right of the support chassis 10 performs a function to absorb the load. Then, the upper wing 13 at the right of the support chassis 10 moves downwardly in -Z direction and the connecting arm 20 at the upper wing 13 by a shaft 26 tilts in a predetermined tilting angle a. At the same time, the cab 1 is to rotate around X-direction in a clockwise. If a phase of vibrations is shifted, the upper wing 13 at the right of the support chassis 10 moves upwardly in +Z direction, and thus the cab 1 is to rotate around X-direction in a counter-clockwise.

Meanwhile, referring to Fig. 8, if a load is forced to the left of the cab 1, the damping member 40 installed in the lower wing 11 at the left of the support chassis 10 performs a function to contract the cylinder 41 so that the load can be absorbed by the damping member 40. Then, the upper wing 13 at the left of the support chassis 10 moves downwardly in -Z direction and the connecting arm 20 at the upper wing 13 by a shaft 26 tilts in a predetermined tilting angle a. At the same time, the cab 1 is to rotate around X-direction in a counter-clockwise. If a phase of vibrations is shifted, the upper wing 13 at the left of the support chassis 10 moves upwardly in -Z direction, and thus the cab 1 is to rotate around X-direction in a clockwise.

Fig. 9 is a perspective view of a cab suspension apparatus in a state where a cab is suspended when a load owing to vibrations is dynamically applied through each of the support chassis.

According to an embodiment of the present disclosure, when a load depending on vibrations is applied to the machine frame 2, the cab 1 is movably or rotatably supported by tilting each of the connecting arms 20 linked to the connecting rods. When vibration occurs, each of the connecting arms 20 is individually tilted within a predetermined tilt angle. For example, referring to the Fig. 9, if the damping member 40-1 is extended at a height of HI and the damping member 40-2 opposite to the damping member 40-1 can be retracted at a height of 112 lower than H I , the cab 1 can be rotatably supported on each of the connecting rods 32 and 34 along X-direction and/or Y-direction.

Simultaneously, the damping member 41-1 may be extended at a height of H3 and the damping member 41 -2 opposite to the damping member 41-1 may be retracted at a height of 114 lower than 113. then the cab 1 can be rotatably supported on each o the connecting rods 32 and 34 along X-direction and/or Y-direction. The heights of HI , H2, H3 and H4 along Z-direction may be variably or dynamically adjusted depending on the predetermined suspension requirements for construction machines. It may be understood that the cab 1 can be yawed and suspended depending on vibrations or the force causing vibrations.

Fig. 10 is a schematic diagram of a hauler equipped with a cab suspension apparatus for according to an embodiment of the present disclosure. Referring to the Fig. 10, a suspension apparatus of the present disclosure is embodied for a hauler 50. There is advantageous in that, when vibrations are occurred, the cab 1 of the hauler 50 can be rotated on the connecting rods 32 around X-direction and moved upwardly or downwardly along the Z-direction, and thus a load of the cab 1 is supported by tilting the connecting arms 20 linked to the connecting rods 32.

Fig. 1 1 is a schematic diagram of a wheel loader equipped with a cab suspension apparatus for according to another embodiment of the present disclosure. Referring to the

Fig. 10, a suspension apparatus of the present disclosure is embodied for a wheel loader 60.

According to another embodiment, the suspension mechanism including each of the connecting arms 20, each o the support chassis 10a, 10b and each of the damping members 40 is configured to be arranged in the directions of right and left of the cab 1 in the same principle mentioned above. There is advantageous in that, when vibrations are occurred, the cab 1 of the hauler 60 can be rotated on the connecting rods 32 around Y-direction and moved upwardly or downwardly along the Z-direction, and thus a load of the cab 1 is supported by tilting the connecting arms 20 linked to the connecting rods 32.

It should be noted that a cab, according to the present disclosure, is not limited to the cab for the hauler or wheel loader as shown in the embodiments, but can be widely used for various construction machines equipped with a ballast system.

Although the invention has been described with reference to the preferred embodiments in the attached figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.