JP2902214B2 - Operator's cab of work machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cab of a working machine provided in a working machine such as a hydraulic shovel, and more particularly to a working machine of a working machine which absorbs vibration transmitted from a body frame of the working machine to the cab. Driver's cab.

[0002]

2. Description of the Related Art FIGS. 6 to 10 show a hydraulic shovel as an example of a conventional working machine with a cab.

In the figure, 1 is a lower traveling body, 2 is a turning device, 3
Denotes an upper revolving unit that is rotatably mounted on the lower traveling unit 1 via the revolving unit 2 and constitutes a working machine main body. The upper revolving unit 3 includes a revolving frame 4 as a main body frame forming a frame structure. A machine room 5 provided on the turning frame 4, a driving room main body 8, which is provided on the turning frame 4 at the front left side of the machine room 5, An operator's cab 6 including various operating levers and instruments provided, and a turning frame 4 located at the rear side of the machine room 5.
And a counterweight 7 provided at the rear of the upper revolving unit 3 with respect to a working device 17 described later.

[0004] Reference numeral 8 denotes an cab main body which is disposed on the revolving frame 4 and forms a main body of the cab 6. As shown in FIG. 7, the cab main body 8 is formed by pressing a thin steel plate. By welding, a rectangular ceiling portion 8A extending in the front-rear direction, a substantially V-shaped front portion 8B having a vertically intermediate portion protruding forward, and a substantially vertical surface with respect to the revolving frame 4 are formed. Left and right side portions 8 of a substantially pentagonal shape provided with portions that protrude forward according to the shapes of the vertically elongated rear surface portion 8C and the shapes of the rear surface portion 8C and the front surface portion 8B.
D, 8D (only one is shown) and the like are formed as a box-shaped cab box. The cab body 8
A door 9 is provided on the left side surface portion 8D of the driver's cab main body 8 via a floor panel bracket 8E on the lower surface side of the cab main body 8.
Is attached.

Reference numerals 11, 11,... Denote lower buffer supports which elastically support the cab main body 8 on the revolving frame 4, and the lower buffer supports 11 are, as shown in FIGS. It is composed of an anti-vibration rubber 12, a spacer 13, and respective stoppers 14, and the like. Each of the lower buffer supports 11 is located between the floor plate 10 of the driver's cab body 8 and the turning frame 4.
Thereafter, a total of four (only two are shown) are provided separated from each other to the left and right, so that the vibration from the turning frame 4 is transmitted to the cab body 8 and attenuated.

Numerals 12 and 12 denote anti-vibration rubbers. Each of the anti-vibration rubbers 12 is formed in a short and thick cylindrical shape by an elastic material such as synthetic rubber, and has a central portion in the axial direction as shown in FIG. An insertion hole 12A is formed. Each of the anti-vibration rubbers 12 is disposed so as to be coaxial with a mounting hole 4B formed in the upper surface 4A of the revolving frame 4, and sandwiches the upper surface 4A of the revolving frame 4 from above and below.

Reference numeral 13 denotes a spacer made of a metal cylinder having a bolt insertion hole 13A in the axial direction.
Reference numeral 3 denotes a middle portion in the longitudinal direction, which is loosely fitted into the mounting hole 4B of the revolving frame 4, and the upper and lower ends of which are the insertion holes 12
A is fitted inside. In addition, the upper and lower end surfaces of the spacer 13 are in contact with a bottom portion 14B of each stopper 14 described later.

Reference numerals 14 and 14 denote stoppers formed into a bottomed cylindrical shape by press-forming a metal plate or the like. As shown in FIG. A bottom portion 14B formed in a shape and having a bolt insertion hole 14A formed in the center, and a cylindrical portion extending in the axial direction from an outer peripheral side of the bottom portion 14B and having a shorter length than the vibration-proof rubber 12. 14C, and the tip side of the cylindrical portion 14C is an opening 14D. The stoppers 14 are attached to each other so that the openings 14D face each other with the upper surface 4A of the revolving frame 4 interposed therebetween through the respective rubber cushions 12, and cover the upper and lower rubber cushions 12 from outside. Have been.

Reference numerals 15, 15,... Denote bolts. The bolts 15 are inserted into the bolt insertion holes 8F of the floor panel bracket 8E from the inside of the cab body 8, and the bolt insertion holes 13A of the spacers 13 and the floor plate. 10 bolt insertion holes 10A,
The inside of each mounting hole 4B of the upper surface portion 4A of the revolving frame 4 extends, and the lower side of the lower buffer support 11, that is, the stopper 14
The operator's cab main body 8 is positioned on the revolving frame 4 by screwing and tightening the nut 16 from below the bottom portion 14B.

Reference numeral 17 denotes a working device provided at a front portion of the upper revolving unit 3, and the working device 17 is provided on a highly rigid bracket portion 4C forming a part of the revolving frame 4 so as to be capable of elevating and lowering. 17A, an arm 17B provided at the tip of the boom 17A so as to be able to move up and down, and a backhoe type bucket 17 provided rotatably at the tip of the arm 17B.
C, these booms 17A, arms 17B,
The bucket 17C is operated by a boom cylinder 17D, an arm cylinder 17E, and a bucket cylinder 17F. The work apparatus 17 rotates the bucket 17C by the bucket cylinder 17F while raising and lowering the boom 17A and the arm 17B by the boom cylinder 17D and the arm cylinder 17E during the excavation work of the earth and sand. Is to be excavated.

In the hydraulic excavator thus configured,
A prime mover and a hydraulic pump (both not shown) driven by the prime mover are provided in a machine room 5 of the upper swing body 3, and hydraulic oil discharged from the hydraulic pump is supplied to the traveling hydraulic motor of the lower traveling body 1 ( By supplying / discharging the cylinders 17D, 17E, 17F, etc. of the working device 17 and the like, these are actuated to drive the vehicle and perform excavation work such as earth and sand.

The lower shock-absorbing supports 11 provided between the floor plate 10 of the cab body 8 and the revolving frame 4 receive vibrations from the engine, vibrations during traveling, and vibrations due to excavation reaction force during work. The transmission from the revolving frame 4 to the driver's cab main body 8 is buffered by the respective vibration isolating rubbers 12 so that the vibration and noise at this time are reduced so that the riding comfort of the driver's cab 6 is not deteriorated.

As shown in FIG. 8, each lower buffer support 11 is provided with an opening 14D of each stopper 14 through the pivot frame 4.
The upper surface portion 4A is opposed to the upper surface portion 4A with a gap S of, for example, about 2 to 3 mm, and the cab main body 8 is restricted from rolling over the gap S in the left and right directions. Thereby, it is possible to prevent the driver's cab main body 8 from colliding with peripheral members such as the boom cylinder 17D and causing a breakage accident.

[0014]

In the prior art described above, for example, four lower buffer supports 11, 11, and 4 are provided between the upper surface 4A of the turning frame 4 and the floor plate 10 of the cab body 8. Are arranged to prevent the transmission of vibrations from the outside to the operator's cab 6, but in practice, the following problems based on the natural frequency occur.

That is, assuming that the weight W of the cab 6, the total spring constant k of each lower buffer support 11, and the gravitational acceleration G, the natural frequency f of the cab 6 in the vertical direction is

[0016]

(Equation 1) Is represented by

Here, the operator's cab body 8 is approximated by a one-degree-of-freedom vibration model as shown in FIG. 9, and when a forced vibration a ₀ cos ωt having an amplitude a ₀ is applied from the lower side in the vertical direction,
Assuming that the amplitude of the vibration transmitted to the cab 6 is a, the vibration transmission rate τ is

[0018]

(Equation 2) Is represented by

At this time, the relationship between the frequency ratio η and the vibration transmissibility τ is as shown in the characteristic line of FIG.
Before and after, vibration increases due to resonance, and the frequency ratio η
It can be understood that the larger the value becomes, the smaller the vibration transmissibility τ becomes 1 and the less the vibration is transmitted.

For example, the weight W of the entire cab 6 is 4
Under the condition of 00 to 500 kg and the total spring constant k of each lower buffer support 11 being 2000 to 8000 kg / cm, the natural frequency f of the cab 6 is approximately 20 to 45H from the above equation (1).
z.

However, the exciting force during the operation of the hydraulic shovel contains many components in these frequency ranges, and the natural frequency f of the cab 6 is in the above range, so that the frequency ratio η Approaching η = 1, causing the driver's cab 6 to vibrate greatly and deteriorating ride comfort.

On the other hand, the turning frame 4 is mounted on the undercarriage 1 so as to be able to turn via the turning device 2, and the portion of the turning frame 4 supporting the cab 6 has a cantilever structure with respect to the turning device 2. Therefore, in addition to simple vertical vibrations through the turning frame 4, vibrations due to horizontal rolling due to torsional vibration of the turning frames 4 and vibrations due to pitching in the front and rear directions are also transmitted to the cab 6 via the turning frames 4. These natural frequencies are lower than the natural frequency in the vertical direction. For example, the natural frequency of rolling is about 10 Hz before and after, and this is the driving wheel of the lower traveling body 1 which becomes the excitation force during traveling. Coincides with the vibration frequency caused by the engagement of the track link with the track link.
The driver's cab 6 is greatly vibrated.

Further, for example, when the spring constant k of each lower buffer support 11 is reduced in order to lower the natural frequency f in the vertical direction, although the vertical vibration can be attenuated, the cab 6 vibrates in the front-back direction. Pitching and rolling in which the cab 6 vibrates in the left-right direction increases. When the pitching or rolling becomes large, the driver's cab main body 8 collides with peripheral members such as the boom cylinder 17D, which causes a new problem in safety and strength.
In the prior art, as shown in FIG.
The gap S between 4D and the upper surface 4A of the revolving frame 4 is set, for example, to about 2 to 3 mm.

However, when the cab body 8 vibrates beyond the gap S due to rolling or pitching, the opening 14D of each stopper 14 collides with the upper surface 4A of the turning frame 4, and the vibration from the turning frame 4 is reduced. There is a problem that it is transmitted directly to the driver's cab main body 8 and the riding comfort of the driver's cab 6 becomes very poor.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention effectively prevents the cab main body from vibrating in the front, rear, left and right directions to cause pitching and rolling. It is an object of the present invention to provide a driver's cab of a working machine capable of effectively damping vertical vibrations and improving ride comfort.

[0026]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a main body frame of a working machine, a box-shaped cab provided on the main body frame and provided with a floor plate on a lower surface side. A cab of a working machine, comprising: a main body; and a plurality of lower buffer supports provided between the floor panel of the cab main body and the main body frame and configured to buffer transmission of vibration from the main body frame to the cab main body. In the above, between the floor plate of the cab main body and the main body frame, a lower vibration restricting link for allowing the cab main body to vibrate in the vertical direction on the main body frame and restricting the vibration in the horizontal direction is provided. Movably connected, furthermore, between the cab main body and the body frame, an upper vibration regulating link which is located above the lower vibration regulating link and forms a parallel link together with the lower vibration regulating link. Pivotable It adopts a configuration comprising a characterized by providing in conjunction.

In this case, it is preferable that each of the lower vibration restricting link and the upper vibration restricting link is rotatably connected to a high rigid portion having high rigidity of the main body frame.

The lower vibration regulating link extends in the left-right direction between the floor plate of the cab body and the body frame, and a pair of link rods spaced apart in the front-rear direction. And a torsion bar composed of a connecting rod connected by a torsion bar. The torsion bar is rotatably connected to the floor plate and the body frame of the cab main body at both left and right ends of each link rod. Good.

Preferably, each of the lower buffer supports comprises a coil spring and a shock absorber that buffer the vibration of the cab body with a relatively small spring constant.

[0030]

With the above construction, the parallel link composed of the upper vibration restricting link and the lower vibration restricting link converts the vibration of the cab body in the horizontal direction (front and rear direction and left and right direction) into vertical vibration. Horizontal vibration can be reduced to a small extent, and rolling and pitching of the cab body can be reliably reduced. In this case, the lower vibration regulating link is constituted by a torsion bar in which each link rod is connected by a connecting rod extending in the front-rear direction, and the torsion bar is connected to the floor plate of the cab body at both left and right ends of each link rod. If it is rotatably connected to the main body frame, a high spring constant against torsional force can be given to the torsion bar, and the cab main body rolls left and right due to torsional vibration from the main body frame, and pitches in the front and rear direction Can be effectively regulated by the torsion bar.

Further, by constituting each lower buffer support with a coil spring and a shock absorber, the vertical vibration of the cab body can be buffered with a small spring constant, and the natural frequency of the entire cab is reduced. In addition, the vertical vibration transmitted to the driver's cab body can be favorably attenuated.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those in the prior art shown in FIG. 6 described above are denoted by the same reference numerals, and description thereof will be omitted.

In the drawing, reference numeral 21 denotes a revolving frame which constitutes a main body frame of the upper revolving unit 3. The revolving frame 21 is substantially the same as the revolving frame 4 described in the prior art. Is formed as a thick high-rigidity portion 21A having high rigidity at a central portion thereof attached to the turning device 2 (see FIGS. 2 and 3). The high rigidity portion 21A is provided on the revolving frame 21.
And a support portion 21B for supporting a driver's cab body 22 described below from below is provided integrally therewith.
1B is formed with a lower rigidity than the high-rigidity portion 21A. A pair of left and right bracket portions 21C, 21C are integrally formed on the front side of the high rigidity portion 21A, and the boom 17A of the working device 17 and the boom cylinders 17D are pin-connected to the respective bracket portions 21C. ing.

Numeral 22 denotes an operator's cab main body provided on the revolving frame 21. The operator's cab main body 22 is almost the same as the operator's cab main body 8 of the operator's cab 6 described in the prior art, and has a ceiling portion 22A,
Front part 22B, rear part 22C and left and right side parts 22
D, 22D, and a door 23 is provided on the left side surface portion 22D. On the lower surface side of the cab main body 22, a floor plate 24 forming a part of the cab main body 22 is provided, and the floor plate 24 is provided on the high rigid portion 21A and the support portion 21B of the revolving frame 21 in the lower portion described later. The entire cab 6 is supported via the buffer support 25.

Numerals 25, 25,... Denote lower buffer supports provided between the turning frame 21 and the floor plate 24 of the cab body 22, and each lower buffer support 25 is
Each of the shock absorbers 26 is disposed between the support portion 21B (high rigidity portion 21A) and the floor plate 24 of the cab body 22 in front, rear, left and right. Each of the coil springs 27 is integrally provided and constantly urges each of the shock absorbers 26 in the extension direction, and each of the coil springs 27 is formed with a relatively small spring constant.

Here, of the lower buffer supports 25,
The lower right buffer support 25 on the rear right side is disposed on the high rigidity portion 21A of the revolving frame 21 as shown in FIG. 3, and the other lower buffer supports 25 are disposed on the support 21B. Each of the shock absorbers 26 is provided with a damping force generating portion 26A which protrudes above the floor plate 24 of the cab body 22.
Each of the damping force generators 26A is configured to attenuate the cab body 22 when the cab body 22 vibrates vertically.

Reference numerals 28, 28,... Denote stoppers provided between the turning frame 21 and the floor plate 24 of the cab main body 22 in parallel with the respective lower buffer supports 25, and the respective stoppers 28 correspond to the respective shock absorbers 26. And the shock absorber 26 is controlled by the coil spring 27
It also prevents excessive stretching and contraction. The stoppers 28 prevent the cab main body 22 from vibrating beyond the stroke end of each shock absorber 26 when a large impact or the like is applied to the cab 6 from the outside.

Reference numerals 29, 29 denote mounting brackets located below the floor plate 24 and erected on the high-rigidity portion 21A of the revolving frame 21.
A is fixed in the front and rear direction by welding or other means,
It protrudes toward the floor plate 24 of the cab main body 22 with a predetermined height. Reference numerals 30 and 30 denote other mounting brackets fixed to the lower surface of the floor plate 24.
Has a U-shaped cross section, and projects downward from the floor plate 24 with a predetermined length. And each of the mounting brackets 3
The reference numeral 0 denotes a leftward distance from each mounting bracket 29 of the revolving frame 21 as shown in FIG.

Reference numeral 31 denotes a high rigidity portion 21A of the revolving frame 21.
Mounting brackets 2 between the cab body 22 and the floor plate 24
9 shows a torsion bar as a lower vibration regulating link rotatably connected via 9, 30; the torsion bar 31 extends in the left-right direction between the floor plate 24 of the cab body 22 and the turning frame 21; A pair of link rods 32, 32 spaced apart in the front-rear direction, and a connecting rod 33 fixed to the base end side of each link rod 32 and connecting the link rods 32 in the front-rear direction to form a substantially U-shape. The connecting rod 33 is provided at both ends in the longitudinal direction thereof with the revolving frame 2.
Each of the mounting brackets 29 is rotatably mounted.

Further, the torsion bar 31 is provided such that the tip end of each link rod 32 is attached to each mounting bracket 30 on the floor plate 24 side.
And restricts the cab main body 22 from being relatively displaced in the left-right direction with respect to the turning frame 21. The torsion bar 31 has a high spring constant with respect to the torsional force between each link rod 32 and the connecting rod 33.
Effectively restricts rolling in the left-right direction and pitching in the front-rear direction.

Reference numeral 34 denotes a mounting plate fixed to the rear surface portion 22C of the cab main body 22 at a height corresponding to the center of gravity of the cab 6,
Reference numeral 35 denotes a mounting bracket provided on the bracket portion 21C of the revolving frame 21 so as to be separated from the mounting plate 34 in the right direction. The lower end of the mounting bracket 35 is fixed to the bracket portion 21C by welding or the like. It projects upward to the level of the plate 34.

Further, reference numeral 36 denotes a mounting plate 3 of the cab main body 22.
4 and the mounting bracket 35 of the turning frame 21
FIG. 2 shows a lateral rod as an upper vibration restricting link rotatably connected to the mounting plate 34 of the cab body 22 and a mounting bracket of the revolving frame 21 as shown in FIG. 35, and extends in the left-right direction to form a parallel link together with the link rod 32 of the torsion bar 31. As a result, the lateral rod 36 and the link rod 32 are moved together with the cab main body 22.
The left-right vibration is converted into a vertical vibration, so that the cab main body 22 is prevented from vibrating in the left-right direction.

The hydraulic shovel according to the present embodiment has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

In this embodiment, however, the lower buffer supports 25 supporting the cab body 22 via the floor plate 24 on the support portions 21 B of the revolving frame 21 and the like are connected to the shock absorber 2.
6 and a coil spring 27, and the excessive extension and contraction of the shock absorber 26 and the coil spring 27 are restricted by a stopper 28, and the high rigid portion 21 A of the revolving frame 21 and the floor plate 24 of the cab body 22 are A torsion bar 31 composed of a pair of link rods 32 extending in the left-right direction and a connecting rod 33 integrally connecting the base ends of the link rods 32 in the front-rear direction is provided between the mounting brackets 29 and 30. A lateral rod 36 is rotatably connected to a central portion of a rear surface portion 22C of the driver's cab main body 22 via a mounting bracket 35 between the bracket portion 21C of the turning frame 21 and Since the lateral link 36 and the link rod 32 of the torsion bar 31 form a parallel link, Such action and effect can be obtained.

First, the revolving frame 21 has a high rigidity portion 21A.
The supporting portion 21B of the revolving frame 21 whose side is rotatably mounted on the lower traveling body 1 via the revolving device 2 and supports the cab body 22 via the respective lower buffer supports 25 and the like is a high rigidity portion 21A. Because it has a cantilever structure for
The revolving frame 21 not only vibrates in the vertical direction due to vibration during traveling or vibration due to excavation reaction force during work, etc., but also the torsion vibration of the support portion 21B in the direction of arrow A in FIG. May be. In this case, the bearing 21B of the revolving frame 21 pitches in the direction indicated by the arrow B in FIG. 4 in the front-rear direction, and rolls in the direction indicated by the arrow C in FIG.

However, in the cab main body 22, the floor plate 24 is connected to the high-rigidity portion 21A of the revolving frame 21 via the torsion bar 31, and the torsion bar 31 has substantially U-shaped link rods 32 and connecting rods 33. Since it has a high spring constant with respect to torsional force between the cabs, it is possible to effectively restrict the cab main body 22 from pitching in the front-rear direction or rolling in the left-right direction due to torsional vibration from the turning frame 21, Vibrations transmitted to the cab body 22 can be effectively buffered by the lower buffer supports 25.

Each of the link rods 32 of the torsion bar 31 forms a parallel link together with the lateral rod 36 as shown in FIGS. 2 and 5, so that the support portion 21B of the revolving frame 21 is connected with the arrow C in FIG. Even in the case of vibration in the direction, the vibration of the cab body 22 in the left-right direction can be converted into the vibration in the up-down direction, and the rolling of the cab body 22 in the left-right direction can be reliably suppressed. Thereby, the vibration of the cab main body 22 in the left-right direction can be restricted to a small extent, and the safety and strength problems such as the collision of the side surface portion 22D of the cab main body 22 with the surrounding members such as the boom cylinder 17D can be reliably achieved. Can be resolved.

Further, each lower buffer support 25 supporting the cab body 22 via the floor plate 24 on the revolving frame 21.
Is composed of a shock absorber 26 and a coil spring 27, and the vertical vibration of the cab body 22 can be buffered with a small spring constant, so that the natural frequency of the entire cab 6 is more reliably compared with that of the prior art. The vertical vibration transmitted to the cab body 22 can be effectively attenuated.

Therefore, according to this embodiment, the cab body 2
2 can be reliably prevented from pitching in the front-rear direction or rolling in the left-right direction due to the torsional vibration of the revolving frame 21 by the combination of the torsion bar 31 and the lateral rod 36. Problems such as collision and safety and strength can be solved. The shock absorber 2 serves as each lower buffer support 25.
By using the coil 6 and the coil spring 27 in combination, the natural frequency of the entire driver's cab 6 can be reduced to effectively attenuate the vertical vibration, and the riding comfort of the vehicle can be greatly improved.

In the above embodiment, the torsion bar 31 as the lower vibration regulating link is connected to the pair of link rods 3.
Although it has been described that the link rods 32 and 32 and the connecting rod 33 are formed in a substantially U-shape, instead of this, for example, a torsion bar is formed by connecting a longitudinal middle part of each link rod by a connecting rod in the front-rear direction. In this case, the left and right ends of each link rod may be rotatably connected to the high rigid portion 21A of the revolving frame 21 and the floor plate 24 of the cab body 22, respectively. do it.

In the above embodiment, each lower buffer support 25 is provided with a shock absorber 26 and a coil spring 27.
However, the present invention is not limited to this. For example, the vibration-proof rubber 12 shown in FIG.
8 may be used. In this case, the gap S shown in FIG. 8 may be increased to about 5 to 30 mm, and the spring constant of the anti-vibration rubber 12 or the like may be set small. .

Further, in each of the embodiments described above, the hydraulic excavator has been described as an example. However, the present invention is not limited to this, and may be applied to a working machine such as a wheel type hydraulic excavator or a hydraulic crane having an operator cab. it can.

[0053]

As described above in detail, according to the present invention, a lower vibration restricting link for permitting the cab body to vibrate vertically on the main body frame and restricting the cab body from vibrating in the horizontal direction is provided. A rotatably connected member is provided between the floor plate of the main body and the main body frame. Further, the lower vibration restricting link is located between the cab main body and the main body frame above the lower vibration restricting link. Because the upper vibration regulation link that constitutes the parallel link is provided so as to be rotatable,
By converting the vibration of the cab body in the horizontal direction (front-back direction and left-right direction) into the vibration in the up-down direction, the vibration in the horizontal direction can be regulated to be small, and the rolling and pitching of the cab body can be reliably reduced.

The lower vibration restricting link is constituted by a torsion bar in which link rods are connected by connecting rods extending in the front-rear direction, and the torsion bar is provided at both left and right ends of each link rod in the cab body. A high spring constant against torsional force can be given to the torsion bar by rotatably connecting to the floor panel and the main body frame, respectively. Pitching in the direction can be effectively controlled by the torsion bar.

Further, by constituting each lower buffer support with a coil spring and a shock absorber,
Since the vertical vibration of the driver's cab can be buffered with a small spring constant, the natural frequency of the entire driver's cab can be reduced, and the vertical vibration transmitted to the driver's cab can be effectively attenuated. Various effects are exhibited, such as a significant improvement.

[Brief description of the drawings]

FIG. 1 is a partially broken external view showing a cab main body, a turning frame, and the like according to an embodiment of the present invention.

FIG. 2 is a sectional view taken in the direction of arrows II-II in FIG.

FIG. 3 is a sectional view taken in the direction of arrows III-III in FIG.

FIG. 4 is a partially broken external view similar to FIG. 1, showing a state in which the revolving frame is subjected to torsional vibration.

FIG. 5 is a sectional view similar to FIG. 2, showing a state in which the revolving frame is subjected to torsional vibration.

FIG. 6 is an overall view showing a conventional hydraulic excavator.

FIG. 7 is a partially broken external view showing a turning frame, a cab main body and the like in FIG. 6 in an enlarged manner.

FIG. 8 is an enlarged sectional view of a lower buffer support and the like shown in FIG. 7;

FIG. 9 is an explanatory diagram for analyzing the vibration of the cab.

FIG. 10 is a characteristic diagram showing a relationship between a frequency ratio of forced vibration to a natural frequency of a cab and a vibration transmissibility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Revolving frame (body frame) 21A High-rigidity part 21B Support part 21C Bracket part 22 Operator's cab main body 24 Floor plate 25 Lower buffer support 26 Shock absorber 27 Coil spring 28 Stopper 31 Torsion bar (Lower vibration regulation link) 32 Link rod 33 Connection Rod 36 Lateral rod

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Zenji Kaneko 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Go Tsuyoshi 650, Kandamachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery (56) References JP-A-5-255950 (JP, A) JP-A-3-200485 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02F 9 / 16

Claims (4)

(57) [Claims] 1. A box-shaped cab main body having a main body frame of a working machine, a floor panel provided on a lower surface of the main body frame, and a space between the floor panel and the main body frame of the cab main body. In a cab of a working machine, comprising a plurality of lower implements, each of which is provided with a lower buffer support that buffers transmission of vibration from the main body frame to the cab main body, between a floor plate of the cab main body and the main body frame. A lower vibration restricting link that allows the cab body to vibrate in the vertical direction on the main body frame and restricts the vibration in the horizontal direction, is provided so as to be rotatable, and further includes the cab main body and the main body frame. Between
An operator's cab for a working machine, wherein an upper vibration regulating link, which is located above the lower vibration regulating link and forms a parallel link together with the lower vibration regulating link, is rotatably connected. 2. The cab of a working machine according to claim 1, wherein the lower vibration restricting link and the upper vibration restricting link are rotatably connected to high rigid portions having high rigidity of a main body frame. 3. The lower vibration restricting link extends in a lateral direction between a floor plate of the cab main body and a main body frame,
The torsion bar includes a pair of link rods spaced apart in the front-rear direction and a connecting rod connecting the link rods in the front-rear direction. The cab of a working machine according to claim 1 or 2, wherein the cab is rotatably connected to the floor panel of the main body and the main body frame. 4. The work according to claim 1, wherein each of said lower shock-absorbing supports comprises a coil spring and a shock absorber for damping the vibration of said cab body with a relatively small spring constant. Machine cab.