JP2006321295A - Cab supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the riding feeling of an operator who rides in a cab comfortable by absorptively damping the vibration of the cab by a simple constitution regarding a structure for supporting the cab of a working machine such as a hydraulic shovel. <P>SOLUTION: This cab supporting structure is equipped with a plurality of first mounts 30 and a plurality of second mounts 50. In this case, a plurality of the first mounts 30 are arranged in a manner to be dispersed on the outer peripheral section of the floor lower surface of the cab 45 of the working machine 40, and elastically support the cab 45 while being mounted on the frame 42a of the working machine. A plurality of the second mounts 50 are arranged at the central section on the floor lower surface of the cab 45, elastically support the cab 45 while bing mounted on the frame 42a of the working machine, and have different damping property from that of the first mounts 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention particularly relates to a structure for supporting a cab on which an operator rides in a work machine such as a hydraulic excavator.

  2. Description of the Related Art Conventionally, work machines such as hydraulic excavators are provided with a vibration-proof mount between a cab and an airframe to reduce vibrations generated during work and travel. For example, FIG. 5 shows a typical cab support structure of a hydraulic excavator. The anti-vibration mount 3 is attached to the hole 2a formed on the upper surface of the left front portion of the swing frame 2 which is a frame of the upper swing body, A cab 1 floor plate (hereinafter referred to as a cab floor) 1 a is placed on the vibration mount 3 to support the cab 1. The anti-vibration mount 3 has a function of attenuating and reducing vibrations. By supporting the cab floor 1a via such an anti-vibration mount 3, vibration generated during work or traveling can be reduced by the working device or the lower traveling. It is difficult to be transmitted from the machine body such as the body to the cab floor 1a.

  In general, a liquid-filled vibration-proof mount such as a viscous mount is used as the vibration-proof mount 3. As shown in FIG. 6, the viscous mount 30 has a cylindrical mount body 31 with one end (lower end in the figure) closed and the other end (upper end in the figure) attached to the swing frame 2, and the interior of the mount body 31. A guide shaft 32 extending in the vertical direction, an elastic body 33 elastically coupling the mount body 31 and the guide shaft 32, a liquid sealing chamber 34 formed at the closed end of the mount body 31, A damping plate 35 having a stopper rubber 35a and an orifice 35b is provided. Attenuating liquid such as silicon oil is injected into the liquid enclosure chamber 34, and the liquid enclosure chamber 34 is divided into a first chamber 34a and a second chamber 34b with an attenuation plate 35 as a boundary. 34b communicates with the orifice 35b.

  When a vibration load is applied to the viscous mount 30, the mount body 31 and the guide shaft 32 are relatively displaced while deforming the elastic body 33. At that time, the damping liquid passes through the orifice 35b and the first chamber 34a. The vibration is attenuated by the resistance force when moving between the second chamber 34b and passing through the orifice 35b. In other words, the elastic body 33 has a function of supporting the load of the cab 1 and delaying the vibration transmission speed from the machine body to the cab 1, and the damping plate 35 moves from the machine body to the cab by moving in the damping liquid. 1 has a damping function for absorbing and reducing the vibration itself transmitted to 1.

As for the structure for supporting such a cab, for example, in Patent Document 1, a vibration isolation mount is inserted into a vibration isolation device hole of a support column erected on a swing frame, and the cab is attached on the vibration isolation mount. Technology is disclosed.
Japanese Patent Laid-Open No. 2003-253701

  Incidentally, as shown in FIG. 5, the anti-vibration mount 3 is generally disposed at the four corners of the outer peripheral portion of the cab floor 1 a and attached to the swing frame 2. The anti-vibration mounts described in Patent Document 1 are disposed at six locations on the outer periphery of the cab floor and are attached to the swing frame. For this reason, in the cab floor 1a in which the anti-vibration mounts are arranged on the outer periphery as described above, when the vibration generating force is applied, the anti-vibration mounts are fixed by the anti-vibration mounts as shown in FIGS. A vibration having the outer peripheral portion as a reflection end (a fulcrum as a node), that is, a so-called membrane vibration occurs. On the other hand, an operator seat 11 is disposed at the center of the cab floor 1a. Therefore, the operator is seated on the center portion of the cab floor 1a where the amplitude of the membrane vibration (particularly the primary mode membrane vibration) is increased, which may cause the operator to get sick and to deteriorate the ride comfort. Therefore, it is desired to improve the ride comfort of the operator by damping the central portion.

  Further, the conventional vibration-proof mount needs to be rigid enough to support the weight of the entire cab. For this reason, for example, even if an attempt is made to suppress the membrane vibration as described above by adjusting the elastic force of the vibration-proof mount, it is necessary to have rigidity sufficient to support the weight of the entire cab, and the elastic force can be set freely. There is a problem that it cannot be done. Thus, in the conventional vibration-proof mount, it is difficult to improve the ride comfort because of the necessity of supporting the total weight, and it is difficult to select the elastic force and rigidity.

  The present invention has been made in view of such problems, and an object thereof is to provide a cab support structure that absorbs and attenuates vibrations with a simple configuration to improve an operator's riding comfort.

  In order to achieve the above object, the cab support structure according to claim 1 is disposed on an outer periphery of a lower surface of a cab floor (cab floor) of a work machine and is placed on a frame of the work machine to elastically support the cab. A plurality of first mounts, and a second mount that is disposed in the center of the lower surface of the floor of the cab, is placed on a frame of the work machine to elastically support the cab, and has a damping characteristic different from that of the first mount. It is characterized by having.

The cab support structure according to claim 2 is characterized in that, in the cab support structure according to claim 1, the plurality of first mounts have a damping characteristic capable of supporting a total weight of the cab.
The cab support structure according to a third aspect is the cab support structure according to the first or second aspect, wherein the second mount is an air mount having an air chamber that absorbs vibration of the cab.

A cab support structure according to a fourth aspect is the cab support structure according to the third aspect, further comprising air pressure adjusting means for pressurizing or depressurizing the air chamber.
The cab support structure according to a fifth aspect is the cab support structure according to any one of the first to fourth aspects, wherein the second mount has a stroke different from that of the first mount.

  The cab support structure according to claim 6 is the cab support structure according to any one of claims 1 to 5, wherein an operator seat is arranged at a center of the floor upper surface of the cab, and the second mount is the operator. It is characterized by being arranged directly under or near the sheet.

  According to the cab support structure of the first aspect, the first mount is disposed on the outer peripheral portion of the cab floor lower surface, the second mount is disposed on the center portion of the cab floor lower surface, and the first mount and second Since the mount has different attenuation characteristics, the function of the first mount and the function of the second mount can be separated. That is, for example, the first mount having a damping characteristic suitable for supporting the weight of the cab is used, and the second mount having a damping characteristic suitable for suppressing vibration (membrane vibration) on the lower surface of the cab. Since a thing can be used, the vibration of the vibration can be absorbed and attenuated with a simple configuration, and the ride quality of the operator who rides on the cab can be improved. And, the second mount in the center is made relatively hard so that the deformation of the cab floor is suppressed to stabilize the cab to make it hard to ride, in other words, to suppress low frequency (long period) vibration. On the contrary, the second mount at the center can be made relatively soft to make it comfortable to ride, or in other words, to suppress high-frequency (short cycle) vibrations.

According to the cab support structure of the second aspect, the function of supporting the weight of the cab is not required for the second mount, and the second mount has a damping characteristic suitable for suppressing vibration of the cab floor. Make it easy to use. That is, the second mount can be specialized in the function of improving the ride comfort of the operator, and can further improve the ride comfort.
According to the cab support structure of the third aspect, since the second mount is an air mount, the damping characteristic of the second mount can be easily made different from the damping characteristic of the first mount, and the vibration of the cab floor can be achieved. It is easy to obtain an attenuation characteristic suitable for suppressing the above.

According to the cab support structure of the fourth aspect, the damping characteristic of the second mount can be easily and arbitrarily changed, and the riding comfort can be adjusted to the preference of the operator.
According to the cab support structure of the fifth aspect, since the strokes of the first mount and the second mount are different, the stroke of the second mount is arbitrarily changed to adjust the vibration amplitude of the cab floor. The configuration can suppress the vibration of the cab and improve the ride comfort for the operator. For example, when the center of the cab floor is completely damped, the vibration mode becomes a node between the outer periphery and the center, and the position of the maximum amplitude moves from the center. If the length is different from the stroke of one mount, the maximum amplitude of vibration can be reduced while maintaining a vibration mode in which only the outer peripheral part is a node and the central part is a belly. That is, the stroke of the second mount can be set so that the maximum amplitude of vibration is reduced.

  According to the cab support structure of the sixth aspect, since the second mount is arranged directly under or near the operator seat, it efficiently absorbs vibration transmitted to the operator and improves the ride comfort of the operator. be able to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a cab support structure according to an embodiment of the present invention. FIG. 1 is a perspective view showing an overall image of a work machine to which the cab support structure is applied. FIG. 2 shows the cab support structure. FIG. 3 is a sectional view of an air mount used for the cab support structure. Note that description will be made by appropriately using FIG. 6 used in the description of the prior art.

  As shown in FIG. 1, a hydraulic excavator 40, which is a typical example of a work machine, includes a lower traveling body 41, an upper revolving body 42 that is rotatably coupled to the lower traveling body 41, and an upper revolving body 42. It is comprised from the working apparatus 43 provided in the front part. The upper turning body 42 has a swing frame (turning frame) 42a that serves as a gantry. A counter weight 44 is provided at the rear end of the swing frame 42a, and an engine, various cooling devices, and the like are provided in front of the counter weight 44. An engine room 46 to be housed inside is provided, and a cab 45 on which an operator gets on the left front is provided.

  As shown in FIG. 2, the cab 45 has a cab body 45 b that forms a side surface and a top surface, and a cab floor 45 a that forms a floor surface, and is configured in a box shape. Although not particularly shown, an operator seat is disposed at a substantially central portion of the cab floor 45a. The cab 45 is elastically supported on the swing frame 42a via vibration-proof mounts 30 and 50 mounted between the cab floor 45a and the swing frame 42a. Here, a state in which the cab 45 is disassembled and lifted upward is shown.

  Here, in the present embodiment, the cab 45 is supported by the five anti-vibration mounts 30 and 50. That is, in addition to the anti-vibration mounts 30 being dispersed and arranged at the four corners of the outer peripheral portion of the cab floor 45a as in the prior art, the center portion of the cab floor 45a, that is, directly below or substantially below the operator seat is newly added. An anti-vibration mount 50 is disposed immediately below. The damping characteristics of the vibration-proof mount are different between the outer peripheral portion and the central portion. That is, the viscous mount 30 shown in FIG. 6 is used at the four corners of the outer peripheral portion, and an air mount 50 described later is used at the central portion.

  The viscous mount 30 is the same as that described in the prior art, and as shown in FIG. 6, a cylindrical (case-like) mount body 31 whose one end is closed, and an inside of the mount body 31 are arranged. The guide shaft 32 formed, the elastic body 33 that couples the mount body 31 and the guide shaft 32, the liquid sealing chamber 34 formed on the closed side (one end) of the mount body 31, and the damping plate 35 having the orifice 35b It has.

  As shown in FIG. 3, the air mount 50 has a known structure in which an air spring 51 is added to the upper portion of the viscous mount 30. That is, the air mount 50 includes an air spring 51 above the elastic body 33 in addition to the mount body 31, the guide shaft 32, the elastic body 33, the liquid sealing chamber 34, and the damping plate 35. The air spring 51 includes an air chamber 51a formed by being surrounded by a bellows 51b, and an air supply / exhaust port 51c for supplying and discharging compressed air to and from the air chamber 51a. The other end of a hose 51d having one end connected to a compressor (not shown) is connected to the air supply / discharge port 51c. A control valve 51e for controlling the air pressure is provided at the base of the hose 51d. Then, the operator adjusts the air pressure of the air chamber 51a by operating the air pressure adjusting means including the compressor and the control valve 51e, and the elastic characteristics (spring constant) and damping characteristics of the air spring 51 of the air mount 50 are adjusted. It can be changed arbitrarily. Therefore, the air mount 50 can absorb vibration transmitted to the cab 45 (cab floor 45a) by the elastic characteristics and damping characteristics of the air spring 51 and the damping characteristics (damping coefficient) of the damping plate 35. The compressor may be newly provided exclusively for the air mount, or an operator seat compressor may be used.

  Further, the mounting of the anti-vibration mounts 30 and 50 will be described in detail. As shown in FIG. 2, a cab for attaching mounts to the cab floor 45a at the four corners of the outer peripheral part and the central part, respectively. Side mount holes 45c and 45d are opened. Also, the swing frame 42a is formed with bracket portions to which the anti-vibration mounts 30 and 50 can be attached at positions corresponding to the above four corners and the center portion, and swing frame side mount holes 42c and 42d are opened in the bracket portions. Is done.

  The cab side mounting holes 45c and 45d and the swing frame side mounting holes 42c and 42d are coaxial, and are assembled in association as shown by a two-dot chain line in FIG. That is, as shown in FIG. 3, the air mount 50 and the viscous mount 30 both have the bent holes 31a of the mount body 31 hooked on the edges of the swing frame side mount holes 42c and 42d, and the mount holes 42c, The guide shaft 32 is inserted into the cab side mounting holes 45c and 45d so that the upper portion of the guide shaft 32 protrudes from the cab floor 45a, and the upper portion of the guide shaft 32 is fastened with a bolt 32a and a nut 60. Has been attached.

Since the cab support structure according to one embodiment of the present invention is configured as described above, the following operations and effects are obtained.
In the hydraulic excavator, vibration is generated during operation and traveling, but the viscous mount 30 is attached to the outer periphery of the cab floor 45a, and the air mount 50 is attached to the center of the cab floor 45a to elastically support the cab 45. Therefore, the functions of the viscous mount 30 at the outer peripheral portion and the air mount 50 at the central portion can be separated. In particular, the vibration is absorbed and attenuated by the air mount 50 at the central portion, so that the ride comfort of the operator is simplified. Can be improved.

  That is, the viscous mount 30 at the outer peripheral portion has a function of supporting the total weight of the cab 45, and the spring constant of the elastic body 33 is increased to some extent so as to have sufficient rigidity, while the air mount at the central portion is provided. Since the function of supporting the weight is not particularly required, the pressure of the air chamber 51a can be adjusted, the spring constant of the air spring 51 can be made relatively small, the air mount 50 can be made soft, and the cab floor 45a It is possible to reduce vibrations during work and travel transmitted to the operator and improve the ride comfort of the operator.

In addition, since the air mount 50 is employed in the central portion as the vibration isolating mount, the damping characteristics can be easily made different from those of the viscous mount 30 on the outer peripheral portion, and vibration of the cab floor 45a can be easily suppressed. Suitable attenuation characteristics can be obtained.
Further, since air pressure adjusting means for increasing or reducing the pressure in the air chamber 51a of the air mount 50 is provided, the damping characteristic of the air mount 50 can be changed more easily and arbitrarily, and riding comfort can be improved. Can be adapted to operator preference. For example, the air chamber 51a is pressurized to harden the air mount 50, and the deformation of the cab floor 45a is suppressed to stabilize the cab 45, while the rugged hard ride [that is, low frequency (long cycle) vibration Or, conversely, the air chamber 51a is depressurized to soften the air mount 50 to make it softer (that is, to reduce the high frequency (short cycle) vibration). The operator can make the ride comfortable according to preference. Note that the hardness and softness of the air mount 50 here are comparisons in the air mount 50 itself and not in comparison with the viscous mount 30.

Further, since the air mount 50 is disposed directly under or near the operator seat, it is possible to efficiently absorb vibration transmitted to the operator and improve the ride comfort of the operator.
Further, the air mount 50 can further improve the riding comfort by balancing the spring constant of the air spring 51 and the damping characteristic (damping coefficient) of the damping plate 35. That is, for example, the damping characteristic of the damping plate 35 can be adjusted by changing the diameter and length of the orifice 35b, and the spring constant of the air spring 51 is adjusted in advance in a well-balanced manner corresponding to the damping characteristic of the damping plate 35. can do.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the viscous mount 30 and the air mount 50 are set to have different attenuation characteristics. However, the viscous mount 30 and the air mount 50 may be set to have different strokes. In this way, the stroke of the air mount 50 is arbitrarily changed to adjust the amplitude of the membrane vibration, and the ride comfort of the operator can be improved while suppressing the vibration of the cab 45 with a simple configuration. For example, the state of the membrane vibration of the cab floor 45a will be described with reference to FIG. 4. When a mount is disposed at the center of the cab floor 45a, a vibration mode A having a node at the center as shown by a broken line appears. The position of the maximum amplitude is shifted from the central portion. However, by making the stroke of the air mount 50 different from the stroke of the viscous mount 30, for example, the stroke of the air mount 50 is made relatively large and the stroke of the viscous mount 30 is made relatively short, which is indicated by a solid line. Thus, the maximum amplitude d of the membrane vibration can be suppressed while the vibration mode B having only the outer peripheral portion as a node is maintained. That is, it is possible to reduce the maximum amplitude d by adjusting the stroke of the air mount 50. The stroke is preferably a stroke per unit load. In this case, the different strokes can also be expressed as different elastic characteristics (spring constants).

  Also, although not particularly shown below the cab floor 45a, a large number of pipes are arranged, so it is difficult to arrange the air mount 50 at the center of the lower surface of the cab floor 45a because of the layout of the pipes. However, by changing the stroke, the air mount 50 can be easily disposed at the center. That is, the air mount 50 can be easily disposed at a location effective for reducing vibration while preventing interference between the maximum amplitude position and the mount arrangement position and the pipe.

In the above embodiment, the bolt head and nut on the upper part of the guide shaft of the anti-vibration mount protrude from the cab floor. The cab floor may be covered with a cover or the like so that the cab floor and the cover are flush with each other.
In the above embodiment, the damping characteristics of each mount are determined so that the viscous mount supports the entire load of the cab. However, the air mount also has a part of the load within a range that does not affect the ride comfort. You may make it bear.

Moreover, in the said embodiment, although the compressor and the control valve were provided as an air pressure adjustment means of the air chamber of an air mount, if the air pressure of an air chamber can be adjusted, it will not be restricted to such a structure.
Moreover, in the said embodiment, although the anti-vibration mount was arrange | positioned in the four corners in the outer peripheral part, the arrangement position and the number of anti-vibration mounts arrange | positioned in an outer peripheral part are not this limitation.
Further, in the above embodiment, as the anti-vibration mount, the viscous mount is used for the outer peripheral portion and the air mount is used for the central portion. However, the type of anti-vibration mount to be mounted is not limited to this, and does not depart from the gist of the present invention. Various types of mounts can be used as appropriate within a range.

1 is a side view of a work machine to which a cab support structure according to an embodiment of the present invention is applied. It is the perspective view which decomposed | disassembled the structure of the cab support structure of FIG. It is sectional drawing of the air mount used for the cab support structure of FIG. It is a figure explaining the membrane vibration which generate | occur | produces in a cab floor based on other embodiment of this invention. It is a disassembled perspective view of the general cab support structure. It is sectional drawing of a general viscous mount. It is a figure explaining the membrane vibration which a general cab support structure generate | occur | produces in a cab floor, Comprising: (a) is the side view, (b) is the front view.

Explanation of symbols

1 Cab 1a Cab floor (cab floor)
2 Swing frame (swivel frame)
2a Anti-vibration mount hole 3 Anti-vibration mount 11 Operator seat 30 Viscous mount (anti-vibration mount)
DESCRIPTION OF SYMBOLS 31 Mount main body 32 Guide shaft 32a Bolt 33 Elastic body 34 Liquid enclosure chamber 34a 1st chamber 34b 2nd chamber 35 Damping plate 35a Stopper rubber 35b Orifice 40 Hydraulic excavator 41 Lower traveling body 42 Upper turning body 42a Swing frame 42c, 42d Swing frame Side mount hole 43 Working device 44 Counter weight 45 Cab 45a Cab floor 45b Cab body 45c, 45d Cab side mount hole 46 Engine room 50 Air mount (anti-vibration mount)
51 air spring 51a air chamber 51b bellows 51c air supply / exhaust port 51d hose 51e control valve (air pressure adjusting means)
60 Nut A, B Vibration mode d Maximum amplitude

Claims (6)

A plurality of first mounts arranged in a distributed manner on the outer periphery of the floor lower surface of the cab of the work machine, and mounted on the frame of the work machine to elastically support the cab;
The cab is disposed at the center of the lower surface of the floor, and is mounted on the frame of the work machine to elastically support the cab, and includes a second mount having a damping characteristic different from that of the first mount.
A cab support structure characterized by that. The cab support structure according to claim 1, wherein the plurality of first mounts have a damping characteristic capable of supporting a total weight of the cab. The cab support structure according to claim 1, wherein the second mount is an air mount having an air chamber that absorbs vibration of the cab. 4. The cab support structure according to claim 3, further comprising air pressure adjusting means for pressurizing or depressurizing the air chamber. The cab support structure according to any one of claims 1 to 4, wherein the second mount has a stroke different from that of the first mount. An operator seat is arranged in the center of the upper surface of the floor of the cab,
The cab support structure according to any one of claims 1 to 5, wherein the second mount is disposed directly under or near the operator seat.

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