JPH06193096A - Operator's cabin support device for construction machine - Google Patents

Abstract

PURPOSE:To ensure the effective prevention of the vibration of an operator's cabin, depending upon the type of a work by pressing the intermediate section of an elastic support body for bearing the body of the cabin with a pusher, and adjusting the spring constant of the elastic support body. CONSTITUTION:A leaf spring 28 is provided to reduce the natural frequency of the whole of an operator's cabin 6, thereby dampening a vibration transmitted to the whole of the cabin 6. Thereafter, a pusher 36 is caused to move in arrow A and B directions on the operation of a travel head 34. Then, the arbitrary position of the lengthwise intermediate section of the leaf spring 28 is pressed with the pusher 38. At the same time, a ratio of length L1 to L2 is pertinently changed, and the spring 28 is adjusted at a spring constant corresponding to the vibration mode of a cabin body 22. At the time of an excavation work, for example, the length L1 and L2 is kept equal to each other, and the body 22 is evenly supported in elastic state, thereby dampening pitching. Also, the length L1 is made long and the length L2 is made short at the time of travel, and a spring constant at a forward section is reduced, thereby increasing the cushion performance of the forward section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cab support device for a working machine suitable for use in a working machine with a cab, such as a hydraulic excavator, and more particularly to damping the vibration transmitted from the frame of the working machine to the cab. And a driver's cab support device for a working machine.

[0002]

2. Description of the Related Art FIGS. 6 to 10 show a cab supporting device for a hydraulic excavator as an example of a transfer chamber supporting device according to the prior art.

In the figure, 1 is a lower traveling structure, 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 main body. The upper revolving structure 3 is a revolving frame 4 as a frame having a frame structure. , A machine room 5 provided on the swivel frame 4
And an operation including a driver's cab main body 8 to be described later, which is provided on the front left side of the machine room 5 on the revolving frame 4 and various operating levers and instruments provided in the operator's cab main body 8. It comprises a chamber 6 and a counterweight 7 provided at the rear of the revolving frame 4 located on the rear side of the machine room 5. The counterweight 7 balances the entire upper revolving structure 3 with a working device 17 described later. It is designed to let you.

Reference numeral 8 denotes a driver's cab main body which is arranged on the swivel frame 4 and constitutes a main body of the driver's cab 6. The operator cab main body 8 is formed by pressing a thin steel plate as shown in FIG. And welding, a rectangular ceiling portion 8A extending in the front-rear direction, a substantially doglegged front surface portion 8B having an intermediate portion in the up-down direction protruding forward, and a substantially vertical surface with respect to the revolving frame 4. The substantially rectangular pentagonal rear surface portion 8C and the substantially pentagonal left and right side surface portions 8 provided with portions projecting forward according to the shapes of the rear surface portion 8C and the front surface portion 8B.
It is formed as a box-shaped cab box composed of D, 8D (only one is shown) and the like. Also, the driver's cab body 8
A door 9 is provided on a left side surface portion 8D of the cab main body 8 and a lower surface side of the cab main body 8 is provided with a floor plate bracket 8E.
A floor plate 10 forming a part of is attached.

Reference numerals 11, 11, ... Show lower cushion supports as elastic supports for elastically supporting the cab body 8 on the swivel frame 4, and each of the lower cushion supports 11 will be described later as shown in FIG. The anti-vibration rubber 12, the spacers 13, the stoppers 14 and the like. The lower cushioning supports 11 are arranged on the floor plate 10 of the cab body 8 and the revolving frame 4 respectively.
A total of four (only two are shown) are provided between and in front, rear, left, and right so as to damp the vibration transmitted from the revolving frame 4 to the cab body 8.

Reference numerals 12 and 12 denote anti-vibration rubbers. Each anti-vibration rubber 12 is formed of an elastic material such as synthetic rubber into a short and thick columnar shape, and its central portion has an axial direction as shown in FIG. An insertion hole 12A extending in the direction is formed. The anti-vibration rubbers 12 are arranged so as to be coaxial with the mounting holes 4B formed in the upper surface 4A of the revolving frame 4, and sandwich 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.
3, the middle portion in the longitudinal direction is loosely fitted in the mounting hole 4B of the revolving frame 4, and the upper and lower ends are the through holes 12 of the respective rubber vibration isolator 12.
It is fitted in A. The upper and lower end surfaces of the spacer 13 are in contact with the bottom portions 14B of the stoppers 14 described later.

Reference numerals 14 and 14 denote stoppers formed in a cylindrical shape with a bottom by press-molding a metal plate or the like, and each stopper 14 is a disk having a diameter larger than that of the vibration-proof rubber 12 as shown in FIG. Bottom portion 14B formed in a circular shape and having a bolt insertion hole 14A formed in the center, and a cylindrical portion extending axially from the outer peripheral side of the bottom portion 14B and having a length dimension shorter than that of the vibration isolating rubber 12. 14C, and the front end side of the cylindrical portion 14C is an opening 14D. The stoppers 14 are mounted so that the openings 14D are opposed to each other with the upper surface portion 4A of the revolving frame 4 interposed therebetween with the anti-vibration rubbers 12 interposed therebetween, and the upper and lower anti-vibration rubbers 12 are covered from the outside. Has been.

The bolts 15, 15 ... Are inserted into the respective bolt insertion holes 8F of the floor plate bracket 8E from the inside of the operator's cab main body 8, and the bolt insertion holes 13A of each spacer 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 swivel frame 4 is extended, and the lower side of the lower cushion 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 the bottom of the bottom portion 14B.

Reference numeral 17 denotes a working device provided in the front portion of the upper swing body 3, and the working device 17 is a boom provided on a high-rigidity bracket portion 4C forming a part of the swing frame 4 so as to be able to move up and down. 17A, an arm 17B provided at the tip of the boom 17A so as to be able to move downward, and a backhoe type bucket 17 provided at the tip of the arm 17B so as to be rotatable.
C, and these boom 17A, arm 17B,
The bucket 17C is operated by a boom cylinder 17D, an arm cylinder 17E, and a bucket cylinder 17F, respectively. Then, when excavating earth and sand or the like, 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, and 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 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 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.

The lower cushioning supports 11 provided between the floor plate 10 of the cab body 8 and the revolving frame 4 are subject to vibrations from the engine, vibrations during traveling, vibrations due to excavation reaction force during work, etc. The vibrations transmitted from the turning frame 4 side to the driver's cab main body 8 are buffered by the respective vibration isolating rubbers 12 to reduce vibration and noise at this time so as not to deteriorate the riding comfort of the driver's cab 6.

Further, as shown in FIG. 8, each lower cushion support 11 has the opening 14D of each stopper 14 in which the revolving frame 4 is fitted.
The upper surface portion 4A is faced with a gap S of, for example, about 2 to 3 mm, and the driver's cab main body 8 is regulated from rolling (rolling) to the left or right beyond the gap S. Thus, it is possible to prevent the driver's cab body 8 from colliding with surrounding members such as the boom cylinder 17D and causing a damage accident.

[0014]

By the way, in the above-mentioned prior art, for example, four lower cushion supports 11, 11, are provided on the upper surface 4A of the revolving frame 4 and the floor plate 10 of the cab body 8. Are arranged to prevent external vibration from being transmitted to the cab 6, but there are the following problems.

That is, assuming that the weight W of the driver's cab 6, the total spring constant k of each lower cushion support 11 and the gravitational acceleration G, the natural frequency f of the driver's cab 6 is

[0016]

[Equation 1] It is represented by.

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

[0018]

[Equation 2] η: Frequency ratio ζ: Damping ratio ω _n : Natural angular frequency C: Damping coefficient C _c : Critical damping coefficient

When this is shown as a characteristic diagram, the frequency ratio η
The relationship between the vibration transmissibility τ and the vibration transmissibility τ is as shown in the characteristic line in FIG. 10. When the frequency ratio η is around η = 1, vibration increases due to resonance, and when the frequency ratio η is large, the vibration transmissibility τ is large. It can be seen that is less than 1 and the vibration is less likely to be transmitted.

The weight W of the entire cab 6 is 400 to
500 kg, total spring constant k of each lower buffer support 11
Is 2000 to 8000 kg / cm, the above formula 1
Therefore, the natural frequency f of the cab 6 is about 20 to 45 Hz.

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

On the other hand, if the spring constant k of each lower buffer support 11 is reduced in order to lower the natural frequency f, the vibration in the vertical direction can be damped, but the cab 6 moves in the front-back direction (Y
The pitching that vibrates in the axial direction and the rolling that vibrates the cab 6 in the left-right direction (the X-axis direction) become large, and the riding comfort deteriorates.

When the pitching or rolling becomes large, the cab main body 8 is moved to the boom cylinder 17
Since it may collide with a peripheral member such as D and cause a damage accident, the gap S between the opening 14D of each stopper 14 and the upper surface 4A of the revolving frame 4 as shown in FIG.
When the driver's cab body 8 vibrates beyond the gap S, the opening 14D of each stopper 14 collides with the upper surface 4A of the revolving frame 4 and the vibration from the revolving frame 4 is driven. There is a problem that it is directly transmitted to the room main body 8 and the riding comfort of the driver's cab 6 becomes very bad.

Further, since the spring constant k of each lower cushioning support 11 is fixed to the same value in front of, behind, left of, and right of the floor plate 10, during the excavation work, the work device 17, the swing frame 4, etc. are used. For the short-term large vibration transmitted to the cab main body 8 and the long-term vibration transmitted to the cab main body 8 via the lower traveling body 1, the turning frame 4 and the like during traveling, the cab main body 8
However, there is a problem that it is not possible to elastically support while controlling the vibration.

The present invention has been made in view of the above-mentioned problems of the prior art. 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 support device for a working machine that is capable of effectively damping vertical vibrations and improving riding comfort.

[0026]

The features of the structure adopted by the present invention to solve the above-mentioned problems are that each elastic support is attached to the floor plate of the cab main body at both ends in the longitudinal direction,
A long leaf spring whose middle portion in the length direction abuts on the frame, and a long spring which is located on the frame and is movable in the length direction of the leaf spring. , And holding means for pressing and holding an arbitrary position on the frame.

In this case, the holding means is provided on the frame, a guide rail extending in the length direction of the leaf spring, and a roller engaging with the guide rail on the upper end side are provided. By driving, a moving head that moves in the length direction of the leaf spring along a guide rail, and a lower end side of the moving head that is capable of expanding and contracting are provided. It is better to have a pusher held between them.

[0028]

With the above structure, for example, if the leaf spring is extended in the front-rear direction or the left-right direction of the operator's cab body and both lengthwise ends are attached to the floor plate of the operator's cab body, the leaf is held on the frame by the holding means. The ratio of the length from any position of the spring to both ends can be set variably, and the spring constant of the leaf spring that supports the floor plate of the operator's cab body on the lower side can be adjusted appropriately in the front-back direction or the left-right direction of the cab body. It is possible to effectively regulate the front-back or left-right vibration of the cab body.

The holding means includes a guide rail extending in the lengthwise direction of the leaf spring, a moving head moving on the guide rail, and an extension / contraction from the moving head to move the leaf spring to the frame. If the pusher is held between the floors, the moving head can be moved to an arbitrary position on the guide rail between the floor plate and the frame by remote control from the cab, etc., and the pusher is extended to adjust the leaf spring holding position. can do.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiments, 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.

First, FIGS. 1 to 3 show a first embodiment of the present invention.

In the figure, reference numeral 21 denotes a revolving frame which constitutes a frame of the upper revolving structure 3, and although the revolving frame 21 is constructed in substantially the same manner as the revolving frame 4 described in the prior art, the revolving frame 21 is The upper surface portion 21A is located on the left front side below the cab main body 22 which will be described below.
B is formed, and the bottom surface of the concave portion 21B is curved in an arcuate shape at the center in the front-rear direction, and a curved portion 21C is formed in which a leaf spring 28 described later is accommodated.

Reference numeral 22 denotes a driver's cab main body disposed on the front left side of the revolving frame 21, and the driver's cab main body 22 has substantially the same structure as the driver's cab main body 8 of the driver's cab 6 described in the prior art, and has a ceiling. It has a part 22A, a front part 22B, a rear part 22C and left and right side parts 22D, 22D. here,
At the lower ends of the front surface portion 22B, the rear surface portion 22C, and the side surface portions 22D, the floor plate brackets 22E, 22E,
Is provided, and a door 23 is provided on the left side surface portion 22D of the cab body 22.

Reference numeral 24 denotes a floor plate forming a part of the operator's cab main body 22, and a pair of mounting brackets 24A, 24A (only the left side is shown) are projected downwardly on the left and right sides of the floor plate 24 and spaced apart from each other in the front and rear direction. The floor plate 24 is fixed to each floor plate bracket 22E of the operator cab body 22 via bolts 25 and nuts 26. Also, each mounting bracket 2 of the floor plate 24
Upper ends of shackles 27 are rotatably pin-connected to 4A and 24A, and both ends of leaf springs 28 are rotatably pin-connected to the lower ends of the shackles 27. The shackles 27 are attached to the cab main body 22.
When the leaf vibrates, the leaf spring 28 is allowed to bend and absorbs a change in length and the like.

28 is each mounting bracket 2 of the floor plate 24.
4A shows a leaf spring attached via each shackle 27, the leaf spring 28 is composed of one long spring plate having attachment portions 28A and 28B at both front and rear ends, and the leaf spring 28 is A total of two (only one is shown) are provided extending in the front-rear direction on both the left and right sides of the floor plate 24. In addition, each leaf spring 28
Has a middle portion in the lengthwise direction curved downward in an arc shape and abuts on the curved portion 21C of the revolving frame 21. The leaf spring 28 has a holding line E-E at an arbitrary position between the mounting portions 28A and 28B by a pusher 36 described later.
Fixedly supported above.

Reference numeral 29 is a curved portion 21 of the revolving frame 21.
The elastic sheet provided on C is shown as the elastic sheet 29.
Is made of, for example, a highly elastic synthetic rubber, and an intermediate portion of the leaf spring 28 is brought into contact with the revolving frame 21 via the elastic sheet 29, so that the leaf spring 28 is elastic on the curved portion 21C of the revolving frame 21. Support.

Reference numeral 30 denotes a spring force adjusting mechanism as a holding means for adjusting the spring force of the leaf spring 28 in the front-back direction of the cab body 22, and the spring force adjusting mechanism 30 includes a guide rail 31, a moving head 34 and a moving head 34, which will be described later. Pusher 36
It consists of

Reference numeral 31 denotes a guide rail provided on the bottom surface of the recess 21B of the revolving frame 21, and the guide rail 31 extends forward and backward along the length direction of the leaf spring 28 as shown in FIGS. Supporting portion 32, and the revolving frame 21 that is bent in a substantially L shape on the upper side of the supporting portion 32.
The rail portion 33 is formed substantially from the curved portion 21C to the left and right. In addition, the rail portion 33
A roller accommodating portion 33B that extends in the front-rear direction and has a guide groove 33A having a U-shaped cross section is provided at the protruding end of the roller accommodating portion 33B. As shown in FIG. 3, the roller 35 of the moving head 34, which will be described later, is rotatably engaged with the guide groove 33A in the roller housing portion 33B.

Reference numeral 34 indicates a moving head, and the moving head 3
Reference numeral 4 denotes a motor unit 34A having a built-in hydraulic motor (not shown).
And the guide rail 3 from the upper end side of the motor section 34A.
The drive shaft 34 </ b> B protruding toward the first side is generally configured. Reference numeral 35 denotes a roller rotatably provided at the tip of the drive shaft 34B. The roller 35 is rotationally driven by the motor portion 34A and rolls in the guide groove 33A of the guide rail 31 to move the moving head. 34 is moved in the front-rear direction of the guide rail 31 (directions indicated by arrows A and B in FIG. 1). Here, the moving head 34 is operated remotely from the driver's cab 6 together with the pusher 36 and the guide rail 3
When the motor portion 34A is operated, the pusher 36 contracts in the arrow C direction to move away from the leaf spring 28.

Reference numeral 36 denotes a pusher provided on the lower end side of the moving head 34. The pusher 36 is roughly composed of a hydraulic cylinder 37 and a rubber 38 described later. The pusher 36 is attached to the guide rail 31 by the moving head 34. After moving along and the moving head 34 stops at the desired position, the hydraulic cylinder 37 extends the piston rod 37B from the tube 37A in the direction of arrow D, and the leaf spring 28 is moved to the revolving frame 21 via the rubber 38. And is pressed and held on the holding line EE.

Reference numeral 38 denotes a rubber made of, for example, synthetic rubber. The rubber 38 is provided at the lower end of the piston rod 37B and appropriately elastically deformed together with the elastic sheet 29 when the leaf spring 28 is pressed onto the curved portion 21C. Then, the leaf spring 28 is clamped from both upper and lower sides so as not to slip in the front-back direction.

Reference numerals 39, 39, ... denote hydraulic shock absorbers provided between the concave portion 21B of the swivel frame 21 and the floor plate 24 of the cab body 22, and each hydraulic shock absorber 39 is swung by the leaf spring 28. When the driver's cab main body 22 elastically supported on 21 vibrates in the vertical direction, the driver's cab main body 22 expands and contracts in response to the vibration, thereby cushioning the vertical vibration of the driver's cab main body 22.

The driver's cab support device for the hydraulic excavator according to the present embodiment has the above-mentioned structure, and its basic operation is not significantly different from that of the prior art.

However, in this embodiment, the floor plates 24 of the operator cab body 22 are provided with mounting brackets 24A, 24A, ... Separated to the front, rear, left, and right, and the middle portion protrudes in an arc shape to provide a swing frame. 21 are attached to the mounting portions 28A and 28B on both ends of the leaf spring 28, respectively, to the mounting brackets 24A.
The shackle 27, 27 is rotatably attached to the shackle 27, and the swing frame 21 is provided with a spring force adjusting mechanism 30 for the leaf spring 28.
A guide rail 31 extending in the length direction of the leaf spring 28, a moving head 34 that moves along a rail portion 33 of the guide rail 31 via a roller 35, and a piston provided on the lower end side of the moving head 34 are provided. Rod 37B
And the pusher 36 that presses and holds an arbitrary position of the leaf spring 28 onto the revolving frame 21 via the rubber 38 by extending the rubber. Thus, the following operational effects are obtained.

That is, by providing the leaf spring 28, the vertical vibration of the cab body 22 can be buffered by the spring having a small spring constant, so that the natural frequency of the cab 6 as a whole is reduced and the cab body is reduced. The upper and lower vibrations transmitted to 22 can be effectively damped. In addition, the moving head 3
4 to move the pusher 36 in the directions of arrows A and B,
By pressing the pusher 36 at an arbitrary position indicated by the holding line E-E in the middle portion in the length direction of the leaf spring 28, the mounting portions 28A, which are located in front of and behind the leaf spring 28 from the position of the holding line E-E, The ratio of the lengths L1 and L2 up to 28B can be appropriately changed, and the spring constant can be adjusted to correspond to the vibration mode of the cab body 22.

In this case, for example, at the time of excavation work, as shown in FIG. 1, the moving head 34 is moved to the center of the length direction of the leaf spring 28, and the pusher 36 on the holding line EE.
By holding the leaf spring 28 against the curved portion 21C of the revolving frame 21, the front and rear spring constants of the leaf spring 28 are set to be substantially equal on the front side and the rear side of the operator cab body 22 based on the dimensions L1 and L2. Yes, the cab body 2
Since the front part and the rear part of 2 can be evenly elastically supported from the lower side, the vibration transmitted from the working device 17 to the cab main body 22 via the swivel frame 21 can be evenly damped in front of and behind the cab main body 22, The pitching of the driver's cab body 22 back and forth can be damped early.

On the other hand, when traveling, the moving head 34 is moved to the position shown in FIG.
Move in the direction of the arrow B in the middle (rear side of the cab body 22),
If the dimension L1 of the leaf spring 28 is lengthened and the dimension L2 is shortened, the leaf spring 28 has its rear portion restricted in deflection and has a large spring constant, and the front portion thereof has a small spring constant, so that the driver's cab 6 has a smaller spring constant. The cushioning property can be enhanced, and the vibration transmitted from the turning frame 21 at the time of traveling can be attenuated at an early stage to improve the riding comfort.

Further, the spring force adjusting mechanism 30 moves the moving head 34 along the guide rail 31 in the front-rear direction between the revolving frame 21 and the floor plate 24 by remote control from the inside of the cab main body 22, Since the pusher 36 can be extended to adjust the holding position of the leaf spring 28 (the position of the holding line EE) as appropriate, the operator cab body 2
2, the spring constant of the leaf spring 28 can be easily adjusted based on the dimensions L1 and L2.

Therefore, according to this embodiment, the holding line E-E
From the position of the pusher 36 which is the upper side, the leaf spring 28
By changing the ratio of the dimensions L1 and L2 to both ends of the cab, the spring constant of the leaf spring 28 before and after the cab body 22 can be changed as appropriate, and vibration in the longitudinal direction of the cab body 22 and the like can be prevented. It can be effectively prevented and the operability and riding comfort can be improved.

Next, FIG. 4 shows a second embodiment of the present invention. The feature of this embodiment is that a leaf spring and a spring force adjusting mechanism as a holding means are extended in the left-right direction of the cab body. It is provided. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals,
The description is omitted.

In the figure, reference numeral 41 denotes a swivel frame. The swivel frame 41 is provided with a recess 41A, which is substantially the same as the swivel frame 21 described in the first embodiment.
The bottom surface of A has a curved central portion in the left-right direction that is curved in an arc shape, and a curved portion 41B that accommodates a leaf spring 44 described later is formed.

Reference numeral 42 denotes a floor plate attached to the floor plate bracket 22E of the operator cab main body 22, and a pair of mounting brackets 42A, 4 are provided on both left and right sides of the floor plate 42 so as to be spaced apart from each other in the front-rear direction.
2B (only the rear side is shown) is projected downward. The shackle 4 is attached to the mounting brackets 42A and 42B.
The upper end side of 3 is rotatably pin-coupled, and the mounting portions 44A, 44B at both ends of the leaf spring 44 are rotatably pin-coupled to the lower end side of each shackle 43. Here, the leaf spring 44 is the floor plate 42.
A total of two pieces (only one piece is shown) are provided extending in the left-right direction on both the front and rear sides of each of the leaf springs 44.
Is abutted on the curved portion 41B. The leaf spring 44 is fixedly supported on the holding line FF by the pusher 36 at an arbitrary position between the mounting portions 44A and 44B.

Reference numeral 45 is a curved portion 41 of the revolving frame 41.
The first spring which is provided on B and elastically supports the leaf spring 44 on the curved portion 41B of the swing frame 41.
The elastic sheet is substantially the same as the elastic sheet 29 described in the above embodiment, and 46 is a spring force adjusting mechanism as a holding means for adjusting the spring force of the leaf spring 44 in the left-right direction of the cab main body 22. The adjusting mechanism 46 is provided on the bottom surface of the recess 41A along the lengthwise direction of the leaf spring 44, and is substantially the same as the guide rail 31 described in the first embodiment. The guide mechanism includes a support portion 47 and a rail portion 48. It is composed of a rail 49, a moving head 34, and a pusher 36.

Then, the spring force adjusting mechanism 46 moves the moving head 34 together with the pusher 36 on the rail portion 33 of the guide rail 31 by remote control from the operator's cab 6, and after the moving head 34 stops at a desired position. The pusher 36 presses and holds the leaf spring 44 against the revolving frame 41 on the holding line FF.

Although this embodiment having the above-described structure has substantially the same operational effects as the first embodiment, in particular, according to this embodiment, the lower side of the floor plate 42 is elastic from the left and right sides. Since the spring constant of the leaf spring 44 that is supported dynamically can be variably adjusted between the left side and the right side of the cab body 22, rolling of the cab body 22 can be effectively suppressed, and operability and riding comfort are improved. be able to.

Next, FIG. 5 shows a third embodiment of the present invention. The feature of this embodiment is that the leaf springs are provided by extending one pair in the front-rear direction and the left-right direction of the cab body,
The leaf force is provided with a spring force adjusting mechanism as a holding means. In this embodiment also, the same components as those in the first embodiment are designated by the same reference numerals,
The description is omitted.

In the figure, reference numeral 51 denotes a swivel frame. The swivel frame 51 has a recess 51B formed in an upper surface 51A thereof, and the bottom surface of the recess 51B is similar to the swivel frame 21 described in the first embodiment. The center portion is curved in an arc shape in the front-rear direction and the left-right direction, and curved portions 51C and 51D that accommodate leaf springs 54 and 56 described later are formed.

Reference numeral 52 denotes a floor plate attached to the floor plate bracket 22E of the operator's cab main body 22, and a pair of mounting brackets 52 are spaced apart on the front and rear sides and the right and left sides of the floor plate 52.
A, 52B, 52C (only one side is shown) are projected downward, and mounting portions 54A, 54B at both ends of the leaf spring 54 are rotatably pin-joined to the mounting brackets 52A, 52B in the front-rear direction via shackles 53. Installed. A leaf spring 56 is similarly attached to the left-right mounting bracket 52C via a shackle 55.

Reference numerals 57 and 58 denote the revolving frame 5 respectively.
The curved portions 51C and 51D of the revolving frame 51 are connected to the leaf springs 54 and 56.
Elastic sheet which is elastically supported on C, 51D, 59, 6
Reference numeral 0 denotes a spring force adjusting mechanism as a holding means for adjusting the spring force of the leaf springs 54 and 56 in the front-rear direction or the left-right direction of the cab main body 22, and here, the spring force adjusting mechanism 5
9 is provided on the bottom surface of the concave portion 51B along the length direction of the leaf spring 54, and is substantially the same as the guide rail 31 described in the first embodiment, the support portion 61 and the rail portion 62.
A guide rail 63, a moving head 34, and a pusher 36. The spring force adjusting mechanism 60 is substantially the same as the guide rail 63 provided along the leaf spring 56, and the moving head 34 and pusher (not shown). It is composed of 36.

In the spring force adjusting mechanisms 59 and 60, the moving head 34 is remotely operated from the operator's cab 6 and the pusher 36 is operated.
Along with this, it moves on the guide rails 63 and 64, and after the moving head 34 stops at the desired position on the guide rails 63 and 64, the pusher 36 presses and holds the leaf springs 54 and 56 against the revolving frame 51. ing.

Although the present embodiment configured as described above can achieve substantially the same operational effects as those of the first and second embodiments, particularly in the present embodiment, the lower side of the floor plate 52 is After that, the spring constants of the leaf springs 54 and 56 can be variably adjusted independently on the left and right sides, and operability and riding comfort can be further effectively improved.

In each of the above embodiments, the leaf spring 28 (44, 54, 56) has been described as being composed of one spring plate, but the present invention is not limited to this, and a plurality of main leaves are provided. A stack of auxiliary leaf springs may be used.

In each of the above-mentioned embodiments, the hydraulic excavator has been described as an example of the working machine, but the present invention is not limited to this, and for example, an operator cab such as a wheel hydraulic excavator or a hydraulic crane is provided. You may use it for a working machine.

[0064]

As described above in detail, according to the present invention, each elastic support for supporting the driver's cab body on the frame is attached to the floor plate of the driver's cab main body at both lengthwise ends, and the lengthwise intermediate portion is provided. Is located on the frame and is movable in the length direction of the leaf spring. Since the leaf spring is configured to be held by being pressed against the frame, the leaf spring is extended in the front-rear direction or the left-right direction of the cab main body and both lengthwise ends are attached to the floor plate of the cab main body. The length ratio of the leaf spring to both ends of the leaf spring can be adjusted variably, and the spring constant of the leaf spring that supports the floor plate of the cab body from below on the frame Depending on, can appropriately adjusted in the longitudinal direction or lateral direction of the cab body, vibrations of the cab body can be effectively regulated by the front-back direction or the lateral direction.

Further, the holding means is provided with a guide rail extending in the length direction of the leaf spring, a moving head which moves along the guide rail, and an extension and contraction from the moving head to move the leaf spring to the frame. If it is configured with a pusher held between them, the pusher is extended to move the moving head between the frame and the floor plate to an arbitrary position on the guide rail by an operation from within the operator's cab main body, and the pusher is extended to move the leaf spring. Since the holding position can be easily adjusted, the vibration can be effectively damped by changing the spring constant according to the work content, the traveling state, etc., and the operability and the riding comfort can be surely improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway external view showing a cab body, a swivel frame, and the like according to a first embodiment of the present invention.

FIG. 2 is an enlarged view showing a spring force adjusting mechanism in FIG.

3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a partially cutaway external view showing a cab body, a swivel frame, and the like according to a second embodiment.

FIG. 5 is an external view similar to FIG. 1, showing a third embodiment.

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

7 is a partially cutaway external view showing an enlarged view of a swivel frame, a cab body, and the like in FIG.

FIG. 8 is an enlarged cross-sectional view of the lower cushioning support and the like shown in FIG.

FIG. 9 is an explanatory diagram for analyzing vibration in a cab.

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

[Explanation of Codes] 21, 41, 51 Revolving frame (frame) 22 Driver's cab body 24, 42, 52 Floor plate 28, 44, 54, 56 Leaf spring 27, 43, 53, 55 Shackle 29, 45, 57, 58 Elastic Seat 30, 46, 59, 60 Spring force adjusting mechanism (holding means) 31, 49, 63, 64 Guide rail 34 Moving head 35 Roller 36 Pusher

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Zenji Kaneko 650 Jinrachicho, Tsuchiura City, Ibaraki Prefecture Tsuchiura Plant, Hitachi Construction Machinery Co., Ltd. Machinery Company Tsuchiura Factory

Claims (2)

[Claims] 1. A frame of a working machine, a box-shaped driver's cab main body provided on the frame and provided with a floor plate on the lower surface side, and a plurality of them are provided between the floor plate and the frame of the operator's cab main body. In the driver's cab support device for a working machine, which comprises an elastic supporter that supports the driver's cab body on the frame, each of the elastic supports is attached to the floor plate of the driver's cab main body at both lengthwise ends. A long leaf spring whose middle portion in the length direction contacts the frame, and a long spring which is located on the frame and is movable in the length direction of the leaf spring. Of these, a cab supporting device for a working machine, comprising a holding means for pressing and holding an arbitrary position on the frame. 2. The holding means is provided on the frame, is provided with a guide rail extending in a length direction of the leaf spring, and a roller engaging with the guide rail at an upper end side, and drives the roller. By doing so, a moving head that moves in the length direction of the leaf spring along the guide rail, and a lower end side of the moving head that is capable of expanding and contracting, and an arbitrary position of the leaf spring when extended extends between the frame and the frame. The cab support device for a working machine according to claim 1, wherein the cab support device comprises a pusher held between the pushers.