JPH0544232A - Driver's cab for working machine - Google Patents

Abstract

PURPOSE:To prevent the generation of rolling and pitching, and to improve comfortableness to drive by cushioning the transmission of vibrations into a driver's cab from the outside. CONSTITUTION:A housing 22 surrounding a driver's cab body 8 from the outside through a clearance G is installed to a revolving frame 4, and the driver's cab body 8 is supported by lower cushioning supporters 11, 11... mounted at four corners on the floor plate 10 side. The driver's cab body 8 is further supported by the four corners of a ceiling section 8 through other four cushioning support members 26, 26... from the housing 22. The spring constant of the lower cushioning supporter 11 is reduced and the intrinsic frequency of a driver's cab 21 can be lowered, and other cushioning supporters 26, 26... cushion rolling and pitching, thus improving comfortableness to drive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in a working machine such as a hydraulic excavator, for damping vibrations from a main body frame, and improving the operability and habitability of an operator. Regarding

[0002]

2. Description of the Related Art FIGS. 7 to 11 show a hydraulic excavator 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
Is an upper revolving structure which is rotatably mounted on the lower traveling structure 1 via the revolving device 2 and constitutes a working machine body. The upper revolving structure 3 is a revolving frame 4 as a main body frame having a frame structure. A machine room 5 provided on the revolving frame 4, a machine room 5 located on the left side of the front of the machine room 5 on the revolving frame 4, and a cab main body 8 and a cab main body 8 which will be described later. The driver's cab 6 includes various operating levers and instruments provided, and a counterweight 7 provided at the rear of the machine room 5 at the rear of the revolving frame 4. The counterweight 7 will be described later. The whole upper swing body 3 is balanced with respect to the working device 17.

Reference numeral 8 denotes a driver's cab main body which is disposed on the swivel frame 4 and constitutes an outer frame of the driver's cab 6. The operator's cab main body 8 is formed by sheet metal stamping and welding a thin steel plate. , A rectangular ceiling portion 8A extending in the front-rear direction
A front surface portion 8B having a substantially doglegged shape in which an intermediate portion in the up-down direction protrudes forward, a vertically long rectangular rear surface portion 8C substantially vertical to the revolving frame 4, and the rear surface portion 8C and the front surface. According to the shape of the portion 8B, left and right side surface portions 8D, 8D having a substantially pentagonal shape provided with a portion projecting forward
(Only one is shown) and the like are formed as a box-shaped cab box.

A door 9 is provided on the left side surface portion 8D of the cab body 8, and a floor plate 10 is attached to the lower surface side of the cab body 8 via a floor plate bracket 8E.

Reference numerals 11, 11, ... Denote lower cushion supports,
As shown in FIG. 9, each of the lower cushioning supports 11 includes two anti-vibration rubbers 12, 12 and a spacer 13 and two stoppers 1.
It is composed of 4 and 14. Here, each lower cushion support 11 is provided between the driver's cab body 8 and the swivel frame 4,
After that, 4 pieces (only 2 pieces are shown) are provided to the left and right,
It is fixed to the swivel frame 4 together with the driver's cab body 8, the floor plate 10, and the like.

Reference numerals 12 and 12 denote anti-vibration rubbers. Each anti-vibration rubber 12 is formed in a short and thick cylindrical shape, and each anti-vibration rubber 12 penetrates the center of the upper and lower surfaces in the axial direction. Insertion hole 1
2A is drilled. Each of the anti-vibration rubbers 12 is arranged two by two on the same axis as the mounting holes 4B formed in the upper surface portion 4A of the revolving frame 4.
A is sandwiched from above and below.

Reference numeral 13 denotes a spacer, which is a metal cylinder having a bolt insertion hole 13A in the axial direction.
The spacer 13 is loosely fitted in the mounting hole 4B of the swivel frame 4, and the insertion holes 12 of the upper and lower anti-vibration rubbers 12, 12 are inserted.
It is inserted so as to fit in A. The upper and lower ends of the spacer 13 are in contact with respective bottom portions 14B of stoppers 14 and 14 described later.

Reference numerals 14 and 14 denote stoppers. Each stopper 14 is formed in a disk shape having a diameter slightly larger than that of the vibration-proof rubber 11, and a bottom portion 14 having a bolt insertion hole 14A in the center thereof is formed.
B, and a cylindrical portion 14C that is axially extended from the outer peripheral side of the bottom portion 14B and that is formed shorter than the vibration isolating rubbers 12.
And an opening portion 14D of the tubular portion 14C, and is formed in a bottomed tubular shape. The stoppers 14 are mounted so that the openings 14D of the swivel frame 4 face each other with the upper surface 4A of the swivel frame 4 sandwiched therebetween, and the upper and lower anti-vibration rubbers 12 are covered from the outside.

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

Reference numeral 17 denotes a working device provided on the front part of the upper swing body 3, and the working device 17 is a boom 17A provided on the front part of the swing frame 4 so as to be able to move up and down, and a tip end of the boom 17A. An arm 17B that can be lifted up and down
And a backhoe type bucket 17C rotatably provided at the tip of the arm 17B. These boom 17A, arm 17B, and bucket 17C are a boom cylinder 17D, an arm cylinder 17E, and a bucket cylinder 1.
Each of them is operated by 7F. Then, the working device 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 by the bucket 17C. Is to be drilled.

In the hydraulic excavator constructed as above,
A prime mover and a hydraulic pump (not shown) driven by the prime mover are provided in a machine room 5 of the upper swing body 3, and pressure oil discharged from the hydraulic pump is used as a traveling hydraulic motor of the lower traveling body 1 ( (Not shown) and the cylinders 17D, 17E, 17F, etc. of the working device 17 are supplied to and discharged from the cylinders 17D, 17E, 17F, etc., thereby operating them so as to drive the vehicle and excavate earth and sand.

At this time, the vibrations transmitted from the revolving frame 4 side to the cab main body 8 by using the vibrations from the engine, the vibrations during traveling, the vibrations due to the excavation reaction force during working, etc. The anti-vibration rubbers 12 and 12 are used to cushion the vibrations and noises so that the riding comfort of the cab 6 is not deteriorated.

[0014]

By the way, in the above-mentioned prior art, the lower cushioning supports 11, 11, ... Are arranged at four positions on the upper surface 4A of the revolving frame 4, and the cab 6 is vibrated from the outside. Is not transmitted.

When the weight of the cab 6 is W, the total spring constant of the lower cushion supports 11, 11, ... Is k and the gravitational acceleration is g, the natural frequency f of the cab 6 is

[0016]

[Equation 1] It is represented by.

[0017] Here, by approximating the cab body 8 in one degree of freedom system vibration model as shown in FIG. 10, the amplitude a _o from below
When the forced vibration a _o cos ωt is applied in the vertical direction, and the amplitude of the vibration transmitted to the cab is a, the vibration transmissibility τ is

[0018]

[Equation 2] It is represented by.

At this time, the relationship between the frequency ratio η and the vibration transmissibility τ is that the frequency ratio η is η as shown in the characteristic diagram of FIG.
It can be seen that the vibration increases due to resonance when around = 1 and the vibration becomes less likely to be transmitted as the frequency ratio η increases.

The mass of the entire cab 6 is 400-5.
Under the conditions of 00 kg and the spring constant of the lower cushioning supports 11, 11, ..., From 2000 to 8000 kg / cm, the natural frequency f of the operator's cab 6 is about 20 to 45 Hz from the above formula 1.

However, this vibration of about 20 to 45 Hz is included in many vibrations during the operation of the hydraulic excavator, and when the natural frequency of the operator's cab 6 is within the above range, the frequency ratio η approaches η = 1. However, there is a problem in that the transmission of vibrations to the driver's cab 6 becomes large and the riding comfort deteriorates.

On the other hand, if the spring constants of the lower buffer supports 11, 11, ... Are reduced in order to reduce the natural frequency f,
Although the vertical amplitude can be suppressed, the cab 6
Causes vibrations in the front-rear direction and rolling in which the driver's cab 6 vibrates in the left-right direction to easily deteriorate the riding comfort. Further, the stress generated in the vibration-proof rubber 12 when the lower cushion support body 11 is bent is However, there is a problem in that the durability of the lower buffer support 11 is adversely affected by the increase.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can reduce the natural frequency of the driver's cab to absorb the vibration, and can suppress the pitching and rolling to improve the riding comfort. The purpose is to provide a driver's cab of the working machine.

[0024]

In order to solve the above-mentioned problems, the feature of the structure adopted by the present invention is that a support frame is fixedly provided on the main body frame so as to surround the driver's cab main body. The other buffer support for buffering the vibration of the cab main body is provided between the cab main body and the lower buffer support.

The support frame may be composed of a head guard that covers the driver's cab body from above, and the other buffer support may be provided between the head guard and the driver's cab body.

[0026]

With the above structure, since the driver's cab main body is supported from the support frame side by the other buffer support, the spring constant of the lower buffer support can be reduced, and the natural frequency of the driver's cab can be reduced to the driver's cab. The transmitted vibration can be reduced. Further, between the support frame and the driver's cab main body, another buffer support buffers the vibration in the front-rear direction and the left-right direction together with the lower buffer support, so that the driver's cab main body can be prevented from rolling or pitching.

[0027]

Embodiments of the present invention will now be described in detail with reference to FIGS. It should be noted that the same components as those of the above-described conventional technique are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 21 denotes a driver's cab of the working machine according to the present embodiment. The driver's cab 21 includes a support frame 22 and other buffer supports 26, 26, ... It is equipped with.

Reference numeral 22 denotes a supporting frame, and each supporting frame 22 is composed of left and right supporting beams 23, 23, a front reinforcing member 24, and a rear reinforcing member 25.

Here, each support beam 23 is formed of a steel material having a substantially U-shaped cross section, and the upper and lower flange portions 23 are formed.
A, 23A and a bottom portion 23B connecting the respective flange portions 23A. The support beams 23 are formed by being bent so as to surround the front surface portion 8B, the ceiling portion 8A, and the rear surface portion 8C of the cab main body 8 so as to surround them from the outside. Part 2
3C, the upper beam portion 23D, and the rear beam portion 23E. The upper beam portion 23D of each support beam 23 is provided with large-diameter through holes 31, 31, ..., Which will be described later, in the flange portion 23A at positions corresponding to the four corners of the ceiling portion 8A of the cab body 8. , Other buffer support 2 described later
The anti-vibration rubber 27 of 6 contacts the upper flange portion 23A of the upper beam portion 23D.

Further, in each of the support beams 23, the lower end of the front beam portion 23C is the front portion of the cab body 8 and the rear beam portion 2
The lower end of 3E is welded to the swivel frame 4 at the rear part of the cab body 8 to form a gap G having a predetermined size between each of the support beams 23 and the cab body 8.

Reference numerals 24 and 25 denote a front reinforcing member and a rear reinforcing member, respectively. The reinforcing members 24 and 25 are made of a steel material having a substantially L-shaped cross section, and each of the upper beam portions 23D of the supporting beams 23 and 23 is provided with the upper beam portion 23D. Each of the upper beam parts 2 at the front and rear
Welded at right angles to 3D, support beam 2
3, 23 are connected to each other.

Reference numerals 26, 26, ... Indicate other buffer supports provided between the cab main body 8 and the support frame 22, and each of the other buffer supports 26 is, as shown in FIG. It is composed of an anti-vibration rubber 27 and two fixing screws 28, 28. The anti-vibration rubber 27 of each buffer support 26 is formed in a solid columnar shape, and the screw portions 28A and 28A of the fixing screw 28 project from the upper and lower surfaces of the anti-vibration rubber 27. Each fixing screw 28 is composed of a screw portion 28A having a male screw formed on the tip side and a short hexagonal columnar fixing portion 28B formed on the base end side.
In the reference numeral 8, fixing portions 28B, 28B are embedded on the upper and lower ends of the vibration-proof rubber 27.

Here, in each buffer support 26, the threaded portions 28A, 28A at the tips are provided at the front and rear of the flange portion 23A located above the upper beam portion 23D of each support beam 23 constituting the support frame 22. Each of the bolt insertion holes 29 provided at two places, a total of four places, and four of the ceiling portion 8A of the cab body 8
The nuts 32, 32 are inserted into the respective bolt insertion holes 30 provided in the corners, and the antivibration rubber 27 is arranged in the through hole 31 provided in the lower flange portion 23A of the upper beam portion 23D.
Is fastened by.

The present embodiment has the structure described above, and its basic operation is not significantly different from that of the prior art.

In this embodiment, however, the cab 21 is fixed to the cab body 8 and the swivel frame 4, and the support frame 22 surrounds the cab body 8 from the outside through the gap G, and the support frame 22.
Since the driver's cab main body 8 is constituted by the other buffer supports 26, 26, ...
The other main cushion supports 26, 26, ... Can support the driver's cab main body 8 by hanging it in the support frame 22, and the spring constant of the lower cushion supports 11, 11 ,. The natural frequency can be reduced.

Therefore, according to this embodiment, it is possible to reduce the transmission of vibrations generated during traveling or working of the hydraulic excavator from the revolving frame 4 to the cab 21, thereby improving the riding comfort. In addition, other buffer supports 26, 26,
By supporting the upper side of the cab main body 8 by ...
It is possible to prevent the driver's cab main body 8 from vibrating back and forth and left and right to prevent rolling and pitching.

Next, FIG. 4 shows a second embodiment of the present invention. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The feature of the present embodiment is that the other buffer supports 26, 26, ... Are connected to the front beam portion 23C and the rear beam portion 23E of each support beam 23.
And the driver's cab main body 8 are provided.

The front beam portion 23C and the rear beam portion 23E of each support beam 23 have large-diameter through holes 41, 41 in the flange portion 23A through which the vibration-proof rubber 27 of each buffer support 26 is inserted. The front beam portion 23C, the rear beam portion 23E, the front surface portion 8B and the rear surface portion 8C of the driver's cab body 8 which are drilled
The buffer supports 26 are arranged between the two.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effect as that of the first embodiment, but especially in this embodiment, in front of the cab body 8,
Since the other buffer supports 26, 26 are provided on the rear side, it is possible to more effectively prevent the occurrence of pitching in which the cab main body 8 vibrates back and forth.

Next, FIG. 5 shows a third embodiment of the present invention. In this embodiment as well, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The feature of this embodiment is that the upper beam portion 23D of each support beam 23 is
.. are provided so as to hang downwardly from the above, and other cushioning supports 26 are provided between the support brackets 51 and the side surface portions 8D of the cab body 8 respectively.

Here, each of the support brackets 51 is
The upper beam portion 2 of each support beam 23 is made of a steel material having a substantially L-shaped cross-section like the rear reinforcing members 24 and 25.
3D is arranged so as to project leftward and rightward at positions corresponding to the reinforcing members 24 and 25, and the end surface of each support bracket 51 is closed by a rectangular steel plate 51A. Then, each buffer support 26 is provided between the cab body 8 and the steel plate 51A that constitutes the end surface of each of the support brackets 51, and supports each side surface portion 8D of the cab body 8 at the four upper positions. It has become.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operation and effect as in the first embodiment. However, particularly in this embodiment, the cab body 8 is replaced by the cab body. 8 between the side surface portions 8D of 8 and the support brackets 51 provided on the support beams 23.
Since it is configured to be supported via 6, 6, ...
It is possible to buffer the vibration of the left-right direction by the respective buffer supports 26, and it is possible to effectively prevent the occurrence of rolling.

Next, FIG. 6 shows a fourth embodiment of the present invention, and the feature of this embodiment is that the support frame is constituted by a head guard. Also in this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 61 denotes a driver's cab provided in a large hydraulic excavator or the like.
It is roughly configured by a driver's cab main body 63 and a head guard 65, which will be described later, provided on the upper part of the two, and between the driver's cab main body 63 and the head guard 65, for example, five other buffer supports 26, 2
6, ... are provided.

Reference numeral 63 denotes a driver's cab body, and the driver's cab body 6
Similar to the cab main body 8 described in the prior art, 3 is composed of a ceiling portion, a front surface portion 63A, a rear surface portion 63B, side surface portions 63C, 63C (only one is shown), which are not shown in the cab main body 63. In the case of a large hydraulic excavator, the upper surface 62A of the revolving frame 62 is higher than the ground.
A door 64 is provided in 3B. The driver's cab body 63 is provided on the revolving frame 62 via a lower cushioning support (not shown) as in the prior art shown in FIGS. 7 to 11.

Reference numeral 65 designates a head guard as a support frame. The head guard 65 includes four columns 65A, 65A, ...
And a guard plate 65B supported by the guard plate 65B. The guard plate 65B is provided at a predetermined interval between the guard plate 65B and the ceiling portion (not shown) of the operator cab body 63, and protects against rocks falling from above. Protects the driver's cab body 63.

Then, the guard plate 65 of the head guard 65
In B, bolt insertion holes (not shown) are formed at four points corresponding to the four corners of the ceiling of the cab main body 63 and at points corresponding to the intersections of the diagonal lines of the quadrangle formed by the four points. A total of five other buffer supports 26, 26, ..., Which are arranged between the ceiling of the chamber main body 63 and each other, are fastened via nuts 32, 32 ,.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same operational effects as in the first embodiment, but especially in this embodiment, the support frame also serves as the head guard 55. As a result, safety and riding comfort can be improved.

In the fourth embodiment, the case where five other buffer supports 26 are provided between the head guard 65 and the ceiling of the cab body 63 has been described as an example. The present invention is not limited to this, and for example, another buffer support 2
The number 6 may be one in the center.

Furthermore, in each of the above-mentioned embodiments, the hydraulic excavator has been described as an example of the working machine with a cab, but the present invention is not limited to this, and a working machine with a cab such as a wheel hydraulic excavator or a hydraulic crane. Can also be applied to.

[0052]

As described in detail above, according to the present invention, a support frame is fixedly provided on the body frame so as to surround the cab body, and a lower buffer support is provided between the support frame and the cab body. Since another cushion support that cushions the vibration of the cab body together with the body is provided, by supporting the cab body from the support frame side by another cushion support, the spring constant of the lower cushion support can be reduced, The natural frequency of the driver's cab can be reduced to reduce the vibration transmitted to the driver's cab, and the stress generated in the lower buffer support when the lower buffer support is bent is suppressed to deteriorate the lower buffer support early. It is possible to solve such problems.

Further, the other buffer support can buffer the vibration in the front and rear direction and the left and right direction together with the lower buffer support between the support frame and the driver's cab main body to prevent the driver's cab main body from rolling or pitching. The riding comfort can be improved.

Furthermore, by using the support frame also as the head guard, it is possible to improve the riding comfort while ensuring safety against falling objects and flying objects.

[Brief description of drawings]

FIG. 1 is an external perspective view of a driver's cab showing a first embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing a driver's cab main body, a support frame, other buffer supports and the like in FIG.

FIG. 3 is an enlarged vertical sectional view showing a buffer support in FIG.

FIG. 4 is a partially cutaway front view of a driver's cab and the like showing a second embodiment of the present invention.

FIG. 5 is an external perspective view of a driver's cab showing a third embodiment of the present invention.

FIG. 6 is an external perspective view of a driver's cab showing a fourth embodiment of the present invention.

FIG. 7 is an overall view showing a hydraulic excavator according to a conventional technique.

FIG. 8 is a partially cutaway front view showing a cab according to the prior art.

9 is an enlarged vertical sectional view showing a lower cushioning support body in FIG. 8. FIG.

FIG. 10 is an explanatory diagram for analyzing vibration of a cab body.

FIG. 11 is a characteristic diagram showing the relationship between the ratio of the frequency of forced vibration to the natural frequency of the cab body and the vibration transmissibility.

[Explanation of symbols]

 4,62 Revolving frame (main frame) 21,61 Driver's cab 8,63 Driver's cab main body 10 Floor plate 11 Lower cushion support 22 Support frame 23 Support beam 26 Other buffer support 65 Head guard (support frame)

Claims (2)

[Claims] 1. A main body frame of a working machine, a box-shaped cab main body provided on the main body frame and provided with a floor plate on the lower surface side, and between the floor plate of the cab main body and the main body frame. In a driver's cab of a working machine, which is provided with a plurality of lower cushioning supports that dampen transmission of vibrations from the main body frame to the cab main body, the main frame includes a support frame surrounding the cab main body. Is provided fixedly, and between the support frame and the driver's cab main body, another buffer support for damping the vibration of the driver's cab main body is provided together with the lower buffer support, and the operation of the working machine is characterized. Room. 2. The support frame is configured by a head guard that covers the driver's cab body from above, and the other buffer support is provided between the head guard and the driver's cab body.
The cab of the work machine described in.