JPH09111808A - Driver's cab of working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance comfort by efficiently damping the vibration transmitted from a frame to a driver's cab main body. SOLUTION: A damping support 12 comprises a link mechanism 13 and a vibration control device 17, the direction of expansion and contraction (B-B direction) of an oil damper 20 which constitutes the vibration control device 17 being approximately perpendicular to the axis of a link lever 16 which constitutes the link mechanism 13. Therefore when a driver's cab main body 9 vibrates on a revolving frame 4, the direction (f) of a force actually working on the oil damper 20 can be made to roughly coincide with the direction (B-B direction) of expansion and contraction of the oil damper 20. Thus by allowing the oil damper 20 to exhibit its damping force to its maximum the vibration transmitted to the driver's cab main body 9 can be damped efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driver's cab of a working machine such as a hydraulic excavator, and more particularly to a working machine for improving habitability by buffering vibrations transmitted from a frame of the working machine to the cab. About the driver's cab.

[0002]

2. Description of the Related Art Generally, a driver's cab of a working machine such as a hydraulic excavator is disposed on a frame of a working machine body, and is provided on a floor plate with a front surface portion, a rear surface portion, left and right side surface portions, and an upper surface portion. An operator's cab main body formed in a box shape and a buffer support provided between the floor plate of the operator's cab main body and the frame for buffering vibration transmitted from the frame to the operator's cab main body.

In the cab of the working machine as described above,
If vibration such as excavation reaction force generated during excavation work such as earth and sand or vibration during traveling is transmitted to the driver's cab through the frame, the habitability in the operator's cab will deteriorate and the operability of the operating lever will decrease. Therefore, the buffer support provided between the floor plate of the cab body and the frame prevents the vibration from the frame from being directly transmitted to the cab body.

As a buffer support according to this type of prior art, for example, in Japanese Utility Model Laid-Open No. 61-89063, a coil spring is provided between the driver's cab body and the frame, and a central portion of the coil spring is provided. Disclosed is a shock-absorbing support body that is positioned and has both ends thereof fixed to a driver's cab body and a frame, and a vibration damping device (shock absorber). Then, the buffer support composed of the coil spring and the vibration isolator elastically supports the cab main body on the frame by expansion and contraction of the coil spring, and when the cab main body vibrates in the vertical direction on the frame, The vibration damping device expands and contracts in accordance with the vertical vibration of the driver's cab main body, and damps the vibration, whereby the vibration transmitted from the frame to the driver's cab main body can be buffered.

Further, in addition to the coil spring and the vibration isolator, a buffer support having a link mechanism in which both ends are rotatably connected to the cab body and the frame is also put into practical use. According to the buffer support including the coil spring, the vibration isolator, and the link mechanism, the link mechanism regulates the moving direction of the cab body with respect to the frame, so that the cab body tilts excessively with respect to the frame. Can be prevented.

[0006]

By the way, in the buffer support composed of the coil spring, the vibration isolator, and the link mechanism as described above, the link mechanism normally moves the driver's cab body in the left-right direction with respect to the frame. Is regulated to allow vertical movement (vibration). Therefore,
When the cab body vibrates, it vibrates not only in the vertical direction but also in the direction allowed by the link mechanism (front-back direction), and the vibration direction has a predetermined inclination with respect to the vertical direction. It will be.

However, since the vibration isolator for damping the vibration of the driver's cab body is arranged so as to expand and contract in a substantially vertical direction, the vibration direction of the operator's cab body and the direction of expansion and contraction of the vibration isolator are inclined. Therefore, there is a problem that the vibration isolator cannot sufficiently exert the action of damping the vibration, and it is not always possible to effectively absorb the vibration of the cab body.

The present invention has been made in view of the above-mentioned problems of the prior art, and the vibration transmitted from the frame to the driver's cab main body can be efficiently damped, and the operability of the working machine can be improved. Is intended to provide.

[0009]

In order to solve the above-mentioned problems, the present invention provides a box-shaped driver's cab main body which is disposed on a frame of a working machine main body and has a floor plate on the lower surface side,
Provided between the floor plate of the cab body and the frame,
The present invention is applied to a driver's cab of a working machine, which comprises a buffer support that buffers vibrations from the frame from being transmitted to the cab main body.

The feature of the means adopted by the invention of claim 1 is that the buffer support is rotatably connected to the frame at one end and to the cab body at the other end.
The vibration damping device is provided with a link mechanism that allows the cab main body to vibrate in the vertical direction on the frame, and a vibration damping device that expands and contracts with the vibration of the cab main body and attenuates the vibration. The configuration is such that the expansion / contraction direction is inclined with respect to the vertical direction.

Further, the invention of claim 2 is such that the direction of expansion and contraction of the vibration isolator is substantially orthogonal to the axis connecting the link mechanism with the frame and the cab main body. .

[0012]

According to the structure of the first aspect, the operator cab main body disposed on the frame via the link mechanism is regulated by the link mechanism due to the vibration transmitted from the frame, and in a direction inclined with respect to the vertical direction. It causes vibration. At this time, since the anti-vibration device is arranged so as to expand and contract in a direction inclined with respect to the vertical direction, the vibration direction of the cab main body and the expansion and contraction direction of the anti-vibration device are brought close to each other, so that The vibration isolator can be expanded and contracted appropriately with respect to vibration, and the damping action of the vibration isolator can be enhanced.

According to the second aspect of the present invention, the expansion and contraction direction of the vibration isolator is set to be substantially orthogonal to the axis connecting the link mechanism with the frame and the cab main body. It is possible to make the swing direction of the mechanism, that is, the vibration direction of the cab main body and the expansion / contraction direction of the vibration isolator substantially coincident with each other. Therefore, when the driver's cab main body is vibrated in a direction inclined with respect to the vertical direction while being regulated by the link mechanism, the vibration damping device expands and contracts in a direction substantially coincident with the vibration direction of the driver's cab main body and attenuates the vibration. Therefore, the vibration transmitted to the cab main body can be efficiently buffered.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

In the drawings, 1 is a lower traveling body, 2 is a turning device, and 3 is an upper revolving structure which is rotatably mounted on the lower traveling body 1 via the revolving device 2 and constitutes a working machine body. The upper revolving structure 3 includes a revolving frame 4 as a frame having a frame structure, a machine room 5 and a driver's cab 6 provided on the upper side of the revolving frame 4, and a counterweight provided on the rear side of the revolving frame 4. 7 and 7.

As shown in FIG. 2, the swivel frame 4 has a thick high-rigidity portion 4A located above the swivel device 2.
And a support portion 4B that extends from the high-rigidity portion 4A and supports a driver's cab body 9 described below from below, and two support portions 4B that are provided on the high-rigidity portion 4A and are spaced apart from each other in the left-right direction. It is composed of beam portions 4C and 4C.

Reference numeral 8 denotes a working device provided in the front portion of the upper swing body 3, and the working device 8 can be lifted and lowered on a high-rigidity bracket portion (not shown) forming a part of the swing frame 4. The boom 8A includes a boom 8A, an arm 8B that can be raised and lowered at the tip of the boom 8A, and a backhoe-type bucket 8C that is rotatably provided at the tip of the arm 8B. , Arm 8B, bucket 8
C is driven by a boom cylinder 8D, an arm cylinder 8E, and a bucket cylinder 8F, respectively. The working device 8 is used for excavating earth and sand, etc.
While the boom cylinder 8D and the arm cylinder 8E raise and lower the boom 8A and the arm 8B, the bucket cylinder 8F rotates the bucket 8C to move the bucket 8C.
C is used to excavate earth and sand.

In the hydraulic excavator constructed as above,
A prime mover and a hydraulic pump (not shown) driven by the prime mover are provided in the machine room 5 of the upper swing body 3, and the pressure oil discharged from the hydraulic pump is used for the traveling hydraulic motor of the lower traveling body 1 ( (Not shown), and the cylinders 8D, 8E, 8F of the work device 8 are supplied to and discharged from the cylinders 8D, 8E, 8F, etc. to operate them, thereby performing a traveling operation and excavation work such as earth and sand.

Reference numeral 9 denotes a driver's cab main body which is disposed on the revolving frame 4 and constitutes a main body of the driver's cab 6. The driver's cab main body 9 is formed by pressing a thin steel plate as shown in FIG. By welding, a rectangular ceiling portion 9A extending in the front-rear direction, a substantially doglegged front surface portion 9B having a vertically intermediate portion protruding forward, and a vertically long surface substantially vertical to the revolving frame 4 are formed. Of a rectangular box-shaped rear surface portion 9C and substantially rectangular left and right side surface portions 9D, 9D (only one of which is shown) provided in accordance with the shapes of the rear surface portion 9C and the front surface portion 9B. Formed as a cab box. A door 10 is provided on the left side surface portion 9D of the cab body 9, and a floor plate bracket 9E is provided on the lower surface side of the cab body 9.
A floor plate 11 forming a part of the operator's cab main body 9 is attached via.

Reference numerals 12, 12, ... Depict buffer supports that elastically support the cab body 9 on the swivel frame 4, and each of the buffer supports 12 is a link mechanism 13 and a vibration isolator 17 described later.
Etc. Then, each buffer support 12
Are provided, for example, between the floor plate 11 of the cab main body 9 and the revolving frame 4 in front, rear, left, and right so that a total of four (only two are shown) are provided. The vibration is transmitted from the revolving frame 4 to the driver's cab main body 9 while being supported.

Reference numerals 13, 13, ... Show link mechanisms arranged between the revolving frame 4 and the floor plate 11 of the operator's cab body 9, and each link mechanism 13 is provided on the lower surface side of the floor plate 11 so as to project therefrom. The floor plate side bracket 14, the frame side bracket 15 fixed to each beam portion 4C of the swivel frame 4, the upper end side is pin-connected to the floor plate side bracket 14, and the lower end side is pin connected to the frame side bracket 15, and the frame side bracket The link lever 16 is swingable around a pin coupling portion with the pin 15. Here, as shown in FIG. 3, the link lever 16 has an axis A-A connecting the connecting portion between the floor plate side bracket 14 and the frame side bracket 15, and the driver's cab body 9 has the swing frame 4 connected thereto.
The link levers 16 are arranged so as to be parallel to each other in a state in which the link levers 16 are lined up at a predetermined angle α with respect to the horizontal direction in a state of being stationary at the top and arranged side by side.

Reference numerals 17, 17, ... Depict vibration damping devices disposed near the link mechanisms 13 between the revolving frame 4 and the floor plate 11 of the cab body 9. An oil damper 20 whose upper end side is rotatably connected to the floor plate 11 via an upper bracket 18, and whose lower end side is rotatably connected to the revolving frame 4 via a lower bracket 19, and the oil damper 20. And a coil spring 21 that constantly urges in the extending direction.

Here, as shown in FIG. 3, the oil damper 20 is arranged so that the center axis BB, which is the direction of expansion and contraction thereof, is orthogonal to the center axis AA of the link lever 16. When the driver cab body 9 vibrates on the revolving frame 4, the oil damper 20 expands and contracts in the central axis BB direction with the vibration of the driver cab body 9 to generate a damping force, as will be described later. The vibration of the driver's cab body 9 is buffered.

The present embodiment has the above-mentioned structure, and the cushioning action against the vibration transmitted from the revolving frame 4 to the cab body 9 will be described below.

First, when the hydraulic excavator is running or when the working device 8 is used.
Revolving frame 4 due to excavation reaction force during excavation work by
When the vibration from is transmitted to the cab body 9, the cab body 9 vibrates on the swivel frame 4.

At this time, the driver's cab body 9 is connected to each link mechanism 1
Since it is supported on the revolving frame 4 via the link frame 3, the driver's cab body 9 is pin-coupled to the floor plate side bracket 14 by the link lever 16 of the link mechanism 13 as shown by a solid line and a two-dot chain line in FIG. The oil damper 20 of the vibration isolator 17 vibrates in the direction of swinging around the portion (the direction of arrow F in FIG. 4), and the central axis B-
A damping force is generated while expanding and contracting in the B direction to buffer the vibration of the cab body 9.

Here, the difference between the cushioning action of the cushioning support 12 of this embodiment and the cushioning action of the conventional cushioning support will be described with reference to FIGS.

First, FIG. 5 shows a buffer support according to the prior art for comparison with this embodiment, and in FIG.
The same components as those of the present embodiment shown in FIG.

In FIG. 5, reference numeral 31 denotes a conventional buffer support, which is similar to the buffer support 12 of the present embodiment in that the link mechanism 13 and the vibration isolator 32 are provided.
However, the oil damper 33 and the coil spring 34 that constitute the vibration isolator 32 are different in that the central axis C-C, which is the expansion / contraction direction thereof, is configured to extend in the vertical direction. .

In the cushioning support 31 according to the prior art constructed as described above, the direction in which the driver cab body 9 swings around the pin connecting portion of the link lever 16 of the link mechanism 13 with the floor plate side bracket 14 (Fig. 5), the oil damper 33 of the vibration isolator 32 moves in a substantially vertical direction along its central axis C-C when displaced from the position indicated by the two-dot chain line to the position indicated by the solid line. Generates damping force while expanding and contracting. However, the force that actually acts on the oil damper 33 due to the vibration of the driver's cab body 9 is indicated by the arrow f around the pin coupling portion between the link lever 16 and the floor plate side bracket 14.
Working in the direction. Therefore, the expansion / contraction direction (C-C) of the oil damper 33 and the direction (f ') of the force acting on the oil damper 33 do not match, and as a result, the damping force of the oil damper 33 can be maximized. Therefore, the vibration transmitted to the driver's cab body 9 cannot be efficiently damped.

On the other hand, the buffer support 1 according to this embodiment
In No. 2, when the operator cab body 9 vibrates in the direction of arrow F as described above and is displaced from the position indicated by the chain double-dashed line to the position indicated by the solid line, the oil damper 20 of the vibration isolator 17 causes the central axis of the link lever 16 to move. A central axis B- which is orthogonal to A-A
A damping force is generated while expanding and contracting along B. At this time, since the central axis BB of the oil damper 20 is configured to be orthogonal to the central axis AA of the link lever 16, the swing direction of the link lever 16, that is, the cab main body 9 The direction (f) of the force that actually acts on the oil damper 20 with the vibration and the direction of expansion and contraction of the oil damper 20 (B-
B) can be substantially matched. As a result, the damping force of the oil damper 20 can be maximized,
The vibration transmitted to the cab body 9 can be efficiently damped.

As described above, according to this embodiment, the buffer support 12 is composed of the link mechanism 13 and the vibration isolator 17, and the central axis B of the oil damper 20 forming the vibration isolator 17 is formed.
By configuring −B so as to be substantially orthogonal to the central axis AA of the link lever 16 that forms the link mechanism 13, when the cab body 9 vibrates on the revolving frame 4,
The direction f of the force actually acting on the oil damper 20 and the expansion / contraction direction (BB) of the oil damper 20 can be substantially matched. Therefore, by maximizing the damping force of the oil damper 20, the vibration transmitted to the driver's cab body 9 can be efficiently buffered, and the habitability in the driver's cab 6 can be significantly improved.

In the above-described embodiment, the case where the upper end side of the oil damper 20 is pin-connected to the floor plate 11 of the operator cab body 9 via the upper bracket 18 has been described, but the present invention is not limited to this. However, the structure is not limited to this, and may be configured to be pin-connected to the link lever 16 or the floor plate side bracket 14, for example.

Further, although the hydraulic excavator has been described as an example in the above-mentioned embodiments, the present invention is not limited to this, and can be applied to a working machine such as a wheel type hydraulic excavator having a cab or a hydraulic crane, for example. .

Further, in the embodiment, the case where the center axis B-B of the vibration isolator 17 is made substantially orthogonal to the center axis A-A of the link mechanism 13 has been illustrated, but both need not necessarily be made substantially 90 °. Instead, it suffices that the central axis BB, which is the expansion / contraction direction of the vibration isolator 17, be inclined with respect to the vertical direction.

[0036]

As described above in detail, according to the first aspect of the invention, since the vibration isolator constituting the buffer support is configured to expand and contract in the direction inclined with respect to the vertical direction, the link mechanism is formed. When the driver's cab main body disposed on the frame via the vibration causes vibration in a direction inclined with respect to the vertical direction while being regulated by the link mechanism, the vibration direction of the driver's cab main body and the expansion / contraction direction of the vibration isolator are Can be brought closer to each other, and the vibration isolator can be expanded and contracted appropriately with respect to the vibration of the cab body. As a result, the damping action of the vibration isolator is enhanced, and the vibration transmitted to the driver's cab body can be efficiently buffered, so that the habitability of the driver's cab can be greatly improved.

Further, according to the invention of claim 2, since the expansion and contraction direction of the vibration isolator is configured to be substantially orthogonal to the axis connecting the link mechanism and the connecting portion between the frame and the cab body, the link is formed. It is possible to make the swing direction of the mechanism, that is, the vibration direction of the cab main body and the expansion / contraction direction of the vibration isolator substantially coincident with each other. Therefore, when the driver's cab body vibrates in a direction inclined with respect to the vertical direction while being regulated by the link mechanism, the vibration isolator expands and contracts in a direction substantially coincident with the vibration direction of the driver's cab body. The damping force can be maximized, and as a result, the vibration transmitted to the cab body can be more efficiently buffered, and the habitability of the cab can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an external view showing a hydraulic excavator to which an embodiment of the present invention is applied.

FIG. 2 is an external view of a driver's cab or the like, in which a part of the slewing frame and the driver's cab main body in FIG. 1 are cut away.

FIG. 3 is an enlarged vertical cross-sectional view showing a link mechanism, a vibration isolator and the like in FIG.

4 is a vertical cross-sectional view showing the operating state of the link mechanism, the vibration isolator and the like in FIG. 3 at the same position as in FIG.

FIG. 5 is a view showing an operating state of a vibration isolator according to the prior art.
It is a longitudinal cross-sectional view of the same position as.

[Explanation of symbols]

 4 Revolving frame (frame) 6 Driver's cab 9 Driver's cab body 11 Floor board 12 Buffer support 13 Link mechanism 16 Link lever 17 Anti-vibration device 20 Oil damper

Claims (2)

[Claims] 1. A box-shaped driver's cab main body provided on a frame of a working machine main body and provided with a floor plate on a lower surface side, and provided between the floor plate of the operator's cab main body and the frame, and the frame. In a driver's cab of a working machine, which comprises a buffer support that buffers vibrations from the vehicle to the driver's cab main body, one end of the buffer support is rotatable to the frame and the other end is rotatable to the cab main body. A link mechanism that allows the driver's cab main body to vibrate in the vertical direction on the frame, and a vibration damping device that expands and contracts with the vibration of the driver's cab main body and attenuates the vibration. An operator's cab of a working machine, characterized in that the vibration device is arranged such that its expansion and contraction direction is inclined with respect to the vertical direction. 2. The operation of the working machine according to claim 1, wherein the expansion and contraction direction of the vibration isolator is configured to be substantially orthogonal to an axis connecting the link mechanism, the frame, and the connecting portion between the frame and the cab body. Room.