JP2012082595A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase attaching strength between a cab supporting sponson beam and a side frame even when a falling regulation device is attached to a weak part of the cab supporting sponson beam.SOLUTION: A cab supporting sponson beam 7 for supporting the rear side part of a cab 8 on a revolving frame 5 is formed by being bent into a J shape to be a vertical plate part 7A extended in left and right directions, an upper side horizontal plate part 7B projected in a front direction from the upper end part of the vertical plate part 7A and a lower side horizontal plate part 7C projected in the front direction from the lower end part of the vertical plate part 7A, and a vibration-proof mount and the falling regulation device are arranged at the upper side horizontal plate part 7B. Then, a reinforcing member 25 is provided between the front end of the upper side horizontal plate part 7B of the cab supporting sponson beam 7 and a left side frame 5D. Thus, stress transmitted from the cab supporting sponson beam 7 to the left side frame 5D is dispersed by the reinforcing member 25, and the strength of a fixed part is increased.

Description

  The present invention relates to a construction machine such as a hydraulic excavator in which a cab is mounted on a vehicle body frame via an anti-vibration mount.

  In general, a hydraulic excavator, which is a representative example of a construction machine, is a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and can be raised and raised on the front side of the upper revolving body. And a working device provided.

  The revolving frame constituting the upper revolving structure includes a center frame that is pivotably mounted on the lower traveling structure, and left and right sides that extend forward and rearward at left and right positions away from the center frame. A frame and a plurality of overhanging beams extending from the center frame to the outside in the left and right directions and supporting the side frame at the tip portion. The swivel frame is provided with a cab support portion on the left front side, and the overhanging beam located on the rear side of the cab support portion is formed as a cab support overhanging beam.

  The swivel frame is provided with a cab located above the cab support portion and the cab support extending beam, and a driver seat on which an operator is seated, various levers, and the like are provided in the cab. An anti-vibration mount is provided between the cab, the cab support portion, and the cab support extending beam to support the cab in a state in which vibration is buffered with respect to the revolving frame.

  The anti-vibration mount incorporates a damping force generating means in a main body portion attached to, for example, a turning frame, and an attachment screw connected to the damping force generating means is attached to the cab. The mounting screw is attached to the main body via an elastic rubber member so that it can be freely displaced with respect to the main body. As a result, the vibration proof mount attenuates the vibration transmitted from the swivel frame to the cab during running and work by the damping force generating means by displacing the mounting screw with respect to the main body, and reduces the vibration transmitted to the cab. Yes.

  Here, the hydraulic excavator may fall, for example, when working in an unreasonable posture on a steep slope, and when the excavator falls, a large load acts on the side of the cab. . When a large load is applied to the cab from the side, the outside of the cab is lifted and displaced greatly, so that the damping force generating means, the rubber member, and the like of each anti-vibration mount may be damaged.

  In view of this, the excavator is provided with an overturn restricting device that is positioned between the cab and the cab-supporting overhanging beam and restricts each vibration-proof mount from being largely displaced beyond the normal stroke. This overturning control device mechanically engages the slewing frame and the cab when the cab is about to fall, and the anti-vibration mount is about to be displaced greatly beyond the normal stroke. It restricts displacement. (For example, refer to Patent Document 1 and Patent Document 2).

JP 2010-95999 A JP 2001-193103 A

  In each patent document mentioned above, the fall control apparatus is provided between the turning frame and the cab. Since the overturning restriction device supports the cab that is about to fall over, a large stress acts on the cab supporting overhanging beam of the revolving frame when the overturning restriction device is engaged. The extension beam for supporting the cab is formed in a U shape and an L shape from a flat upper surface plate and a side surface plate extending downward from the end of the upper surface plate, and the overturn regulating device is provided on the upper surface plate. . At this time, since a large load acts on the position of the upper surface plate of the cab supporting overhanging beam where the overturning restriction device is disposed, the overturning restriction device is located near the side plate that is advantageous in strength among the upper surface plate. It is desirable to arrange.

  However, the hydraulic excavator includes a small swing type hydraulic excavator in which the upper swing body is downsized so that the swing operation can be performed in a narrow site. In this hydraulic excavator, the engine, pump, motor, tank, electrical equipment, etc. must be arranged in a small space in the upper swing body, and these must be connected appropriately, so the mounting position of the overturning restriction device cannot be set freely. There is a case. In such a case, the overturning restriction device cannot be placed at a high strength position of the cab support overhanging beam, and the load (stress) is concentrated on the mounting portion of the cab support overhanging beam with respect to the side frame. May be damaged.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to provide a cab support overhanging beam and a side frame even when the overturning restricting device is attached to a fragile portion of the cab support overhanging beam. It is an object of the present invention to provide a construction machine that can prevent damage to this portion by increasing the mounting strength between them.

  The construction machine according to the present invention comprises a center frame, a side frame, and an extension beam, and a support structure, a cab support portion is provided on the front side, and one of the extension beams is formed as an extension beam for cab support. A frame, a cab provided above the cab support portion of the vehicle body frame and the cab support extending beam, and defining a living space for an operator therein, the cab support portion of the vehicle body frame, the cab support extending beam, and the cab An anti-vibration mount for supporting the cab in a state in which vibration is buffered with respect to the vehicle body frame, and a cab support portion of the vehicle body frame, a cab support extending beam, and the cab. A fall regulation that regulates the displacement of the cab beyond the normal stroke of the anti-vibration mount And a location.

  In order to solve the above-mentioned problem, the feature of the configuration adopted by the invention of claim 1 is that the extended beam for supporting the cab includes a vertical plate portion extending leftward and rightward and an upper end portion of the vertical plate portion. The cab supporting overhanging beam is located between the front end of the horizontal plate portion and the side frame. The reinforcing member for reinforcing the space between the cab supporting overhanging beam and the side frame is provided.

  According to a second aspect of the present invention, the reinforcing member includes a vertical plate portion extending downward along the inner surface of the side frame from the front end of the horizontal plate portion of the cab supporting overhanging beam, and a lower end of the vertical plate portion. That is, it is formed as an L-shaped plate body with a horizontal plate portion bent and extended to the front side.

  According to a third aspect of the present invention, the vertical plate portion constituting the reinforcing member includes an upper side portion along the front end of the horizontal plate portion, a side portion along the inner side surface of the side frame, and the upper side portion. That is, it is formed in a triangular shape by a hypotenuse part connecting the side part.

  According to the invention of claim 1, since the cab-supporting extension beam is formed by the vertical plate portion extending in the left and right directions and the horizontal plate portion protruding forward from the upper end portion of the vertical plate portion, The anti-vibration mount and the overturning restriction device can be disposed on the horizontal plate portion.

  For example, even if the construction machine falls down and the cab is pushed from the side and is about to be displaced greatly, the fall regulating device can regulate the displacement of the cab. At this time, since a large load for overturning the cab also acts on the cab-supporting overhanging beam via the overturning restricting device, there is a risk that stress concentration may occur in the fixing portion between the cab-supporting overhanging beam and the side frame. .

  However, since the extension beam for supporting the cab is provided with a reinforcing member between the front end of the horizontal plate portion and the side frame, the cab support is achieved by dispersing stress transmitted from the extension beam for supporting the cab to the side frame, for example. The strength of the fixing portion between the overhang beam and the side frame can be increased.

  As a result, even when a tipping control device is provided on the horizontal plate of the cab-supporting overhang beam that has become structurally fragile because the front side becomes a free end, the reinforcing member increases the strength by dispersing stress. As a result, damage between the cab-supporting overhanging beam and the side frame can be prevented, and durability and reliability can be improved.

  According to the invention of claim 2, the reinforcing member is bent from the front end of the horizontal plate portion of the cab supporting overhanging beam along the inner side surface of the side frame and from the lower end of the vertical plate portion. Thus, an L-shaped plate body is formed by the horizontal plate portion extending to the front side. As a result, the reinforcing member is configured such that the vertical plate portion provided between the cab-supporting overhanging beam and the side frame constitutes the reinforcing member, and the stress transmitted from the cab-supporting overhanging beam to the side frame can be dispersed. In addition, since a horizontal plate portion that is bent and extends to the front side is provided at the lower end of the vertical plate portion, for example, when a reinforcing member is fixed to the side frame using welding means, the welding distance should be increased. And the attachment strength to the side frame can be increased.

  According to the invention of claim 3, since the vertical plate portion of the reinforcing member is formed in a triangular shape by the upper side portion, the side side portion, and the oblique side portion, the stress can be dispersed by this triangular shape. Even a small reinforcing member can increase the strength between the extended beam for supporting the cab and the side frame.

It is a front view which shows the hydraulic shovel applied to the 1st Embodiment of this invention. It is a top view which shows the turning frame in FIG. 1 alone. It is a cross-sectional view which shows the structure of the cab in FIG. It is the external appearance perspective view which looked at the state which mounted the cab in the left front side of the revolving frame from the upper right side. It is the external appearance perspective view which looked at the state which mounted the cab on the left front side of the revolving frame from the lower right side. 3 is a cross-sectional perspective view of a cab support portion, a cab support overhanging beam, and the like seen from the direction of arrows VI-VI in FIG. 2. FIG. It is sectional drawing of the principal part expansion which looked at the turning frame, the cab, the anti-vibration mount, the fall control device, and the reinforcing member from the arrow VII-VII direction in FIG. It is a cross-sectional perspective view of the principal part expansion which shows the attachment state of the reinforcement member with respect to the extension beam for cab support, and a side frame. It is an external appearance perspective view which shows a reinforcement member alone. It is a cross-sectional perspective view of the principal part expansion which shows the extension beam for cab support and reinforcement member by the 2nd Embodiment of this invention with a side frame. It is a cross-sectional perspective view of the principal part expansion which shows the extension beam for cab support by the 3rd Embodiment of this invention with a side frame and a reinforcement member.

  Hereinafter, as a construction machine according to an embodiment of the present invention, a crawler type hydraulic excavator will be described as an example and described in detail with reference to the accompanying drawings.

  First, FIG. 1 thru | or FIG. 9 has shown the 1st Embodiment of this invention. In FIG. 1, reference numeral 1 denotes a crawler-type hydraulic excavator as a construction machine. The hydraulic excavator 1 includes a lower traveling body 2 capable of self-propelling and an upper revolving body 3 mounted on the lower traveling body 2 so as to be capable of swiveling. And a work device 4 that is provided on the front side of the upper swing body 3 so as to be able to move up and down, and that performs excavation work and the like of earth and sand.

  The upper swing body 3 includes a later-described swing frame 5 provided on the lower traveling body 2 so as to be swingable, a later-described cab 8 mounted on the left front side of the swing frame 5, and the cab 8 connected to the swing frame 5. A vibration-proof mount 20 to be described below that supports vibrations in a shock-absorbing state, a tipping restriction device 21 that suppresses large displacement of the cab 8, and a reinforcement between the cab-supporting overhanging beam 7 and the left side frame 5D. The reinforcing member 25 is provided.

  Reference numeral 5 denotes a revolving frame as a vehicle body frame that forms a support member for the upper revolving structure 3. As shown in FIG. 2, the swivel frame 5 is provided with a thick bottom plate 5A extending in the front and rear directions, and standing upright and extending in the front and rear directions on the bottom plate 5A. Left and right working device mounting plates 5B and 5C to which 4 is mounted, and left and right extending forward and rearward at the left and right positions away from the bottom plate 5A and the respective working device mounting plates 5B and 5C. The side frames 5D and 5E, and a plurality of overhanging beams 5F extending from the bottom plate 5A and the work device mounting plates 5B and 5C to the left and right sides and supporting the side frames 5D and 5E at the tip portions. Has been. The bottom plate 5 </ b> A and the left and right work device attachment plates 5 </ b> B and 5 </ b> C constitute a center frame of the revolving frame 5.

  Further, a cab support portion 6 is provided on the left front side of the revolving frame 5 so as to extend leftward and rightward at a position protruding forward from the bottom plate 5A. The cab support portion 6 constitutes a part of the revolving frame 5, and mount mounting holes 6B are provided at both the left and right side positions of the upper plate portion 6A. The mount mounting holes 6B are described later. The anti-vibration mount 20 is attached.

  Further, out of the plurality of overhanging beams 5F constituting the revolving frame 5, the overhanging beam 5F located at the intermediate portion in the front and rear directions on the left side is an overhanging beam for supporting the cab for supporting the rear side portion of the cab 8. 7 The cab supporting overhanging beam 7 is a long plate-like vertical plate portion 7A extending in the left and right directions so as to form a substantially vertical wall surface, and protrudes forward from the upper end portion of the vertical plate portion 7A to be substantially horizontal. The upper horizontal plate portion 7B extending to the bottom and the lower horizontal plate portion 7C protruding forward from the lower end portion of the vertical plate portion 7A are bent into a substantially J-shaped or L-shaped plate body. It is formed by processing.

  The extended beam 7 for supporting the cab is fixed to the inner side surface 5D1 of the left side frame 5D using welding means at the front end portions (left end portions) of the vertical plate portion 7A, the upper horizontal plate portion 7B, and the lower horizontal plate portion 7C. Yes.

  Mount attachment holes 7D are respectively provided at the left and right side positions of the upper horizontal plate portion 7B, and a vibration-proof mount 20 described later is attached to each of the mount attachment holes 7D. Here, when the excavator 1 falls, a left side surface of a cab 8 described later collides with the ground, and a large load acts in a direction separating the left side of the revolving frame 5 and the left side of the cab 8. Therefore, a through hole 7E is provided on the left side of the upper horizontal plate portion 7B, which is positioned on the front side (closer to the front end portion) than the mount mounting hole 7D and into which a fall restricting device 21 described later is inserted.

  The cab-supporting overhanging beam 7 configured as described above is provided as a part of the upper swing body 3 constituting the small swing type hydraulic excavator 1 and is restricted by a narrow installation space. In some cases, the mounting form cannot be optimized in terms of strength. That is, it is desirable in terms of strength that the overturning restriction device 21 on which a large load acts is disposed at the rear side position of the upper horizontal plate portion 7B close to the vertical plate portion 7A. However, the through hole 7E of the overturning restricting device 21 is disposed at the front side position of the upper horizontal plate portion 7B depending on conditions such as the installation location of the equipment, wiring, and piping.

  Next, 8 is a cab mounted on the left front side of the revolving frame 5. The cab 8 is provided on the upper side of the cab support portion 6 and the cab support overhanging beam 7 via an anti-vibration mount 20, which will be described later, and defines a living space in which an operator gets on. As shown in FIGS. 3 to 5, the cab 8 is generally configured by a base frame body 9, a cab box 14, a floor plate 16, and the like which will be described later.

  Reference numeral 9 denotes a base frame provided on the lower side of the cab 8, and the base frame 9 constitutes the cab 8 together with the cab box 14, the floor board 16 and the like. As shown in FIGS. 3 and 4, the base frame 9 is a rectangular frame structure that is long in the front and rear directions by a front connection frame 9A, a rear connection frame 9B, a left connection frame 9C, and a right connection frame 9D. It is formed as. Further, a left front mounting base 10, a right front mounting base 11, a left rear mounting base 12, and a right rear mounting base 13, which will be described later, are provided at four corners of the base frame body 9 forming the frame structure.

  Reference numeral 10 denotes a left front mounting base which forms a part of the base frame body 9 and is disposed at a left front corner position of the base frame body 9. The left front mounting base 10 is formed as a single block body by, for example, casting means or forging means. As shown in FIG. 3, the left front mounting base 10 is formed in a substantially triangular shape in a plan view, and a mounting mounting hole 10A into which a mounting screw 20B of a vibration isolating mount 20 described later is inserted is disposed at a substantially central position. Is provided.

  Reference numeral 11 denotes a right front mounting base which forms a part of the base frame body 9 and is disposed at a right front corner position of the base frame body 9. The right front mounting base 11 is formed, for example, as a single cast part or a forged part in substantially the same manner as the left front mounting base 10 described above. The right front mounting base 11 is formed in a substantially triangular shape in plan view, and a mount mounting hole 11A is provided at a substantially central position.

  Reference numeral 12 denotes a left rear mounting base disposed at a left rear corner position of the base frame body 9. The left rear mounting base 12 is substantially the same as the left front mounting base 10 described above, for example, a single cast part or Molded as a forged part. As a result, the left rear mounting base 12 has sufficient strength to connect the cab 8 to the vibration proof mount 20 together with the other mounting bases 10, 11, and 13.

  The left rear mounting base 12 is formed in a substantially trapezoidal shape in a plan view, and a mounting mounting hole 12A into which a mounting screw 20B of a vibration-proof mount 20 described later is inserted into a rear position outside the cabin of the cab 8. Is provided. In addition, a stopper mounting hole 12B is provided at a front position of the left rear mounting base 12 that is a room of the cab 8, and a stopper bolt 22 of a fall restricting device 21 described later is screwed into the stopper mounting hole 12B from below. Is done.

  Reference numeral 13 denotes a right rear mounting base disposed at a right rear corner position of the base frame body 9. The right rear mounting base 13 is substantially the same as the left front mounting base 10 described above, for example, a single cast part or Molded as a forged part. The right rear mounting base 13 is formed in a substantially trapezoidal shape in a plan view, and a mounting mounting hole 13A into which a mounting screw 20B of a vibration isolating mount 20 described later is inserted in a rear position outside the cab 8 in the room. Is provided.

  Here, since the mount mounting holes 12A and 13A of the left rear mounting base 12 and the right rear mounting base 13 are disposed outside the cab 8, the bolts can be easily bolted from the outside with respect to the mounting screws 20B of the vibration isolating mount 20. Can be stopped. Thereby, even when the installation space of the cab 8 cannot be widened, the cab 8 (anti-vibration mount 20) can be easily attached and detached.

  Reference numeral 14 denotes a cab box provided on the base frame body 9, and the cab box 14 constitutes the outer shape of the cab 8. The cab box 14 is formed as a box-shaped body by four surrounding surfaces including a front surface portion 14A, a rear surface portion 14B, a left side surface portion 14C, and a right side surface portion 14D, and a top surface portion 14E. The left side surface portion 14C is provided with an entrance 15 that is opened and closed by a door (not shown).

  The cab box 14 is formed as a box-like body having high strength by connecting the front surface portion 14A, the rear surface portion 14B, the left side surface portion 14C, the right side surface portion 14D, and the top surface portion 14E with pillars as ridge lines. The cab box 14 covers the periphery of a driver's seat 17 to be described later, and a lower end portion thereof is fixed to the base frame body 9 using welding means or the like.

  16 is a floor board which obstruct | occludes the lower side of the cab box 14 (refer FIG. 3, FIG. 4). The floor plate 16 constitutes a part of the cab 8 and is formed as a rectangular plate that is long in the front and rear directions so as to be substantially contained in the base frame body 9. The floor board 16 is fastened together with the base frame body 9 by inserting the mounting screws 20B of the vibration proof mount 20 through screw insertion holes (both not shown) at the four corners. Further, the floor plate 16 is bolted to the base frame 9 at the periphery thereof.

  Reference numeral 17 denotes a driver's seat provided in the cab 8 and provided on the floor board 16. The driver's seat 17 is seated by an operator, and work levers 18 for operating the work device 4 and the like are provided on the left and right sides thereof. Further, on the front side of the driver's seat 17, a traveling lever / pedal 19 that is disposed in front of the floor plate 16 and travels the lower traveling body 2 is provided.

  Reference numeral 20 denotes, for example, four anti-vibration mounts (see FIG. 3 and the like) provided between the cab support portion 6 of the revolving frame 5 and the cab support overhanging beam 7 and the cab 8. The cab 8 is disposed at four locations on the left front, right front, left rear, and right rear, and supports the cab 8 with respect to the cab support portion 6 and the cab support extending beam 7 in a state where vibrations are buffered. As shown in FIG. 7, each anti-vibration mount 20 includes, for example, a main body portion 20A in which a viscous liquid is sealed, and a mounting screw 20B extending upward from the main body portion 20A. Is integrally attached to the main body 20A via an annular rubber member.

  Of the four anti-vibration mounts 20, the two anti-vibration mounts 20 located on the left front and right front have left and right mount mounting holes 6 </ b> B whose main body 20 </ b> A is formed in the upper plate 6 </ b> A of the cab support 6. Installed on. Further, the two anti-vibration mounts 20 located at the left rear and the right rear are attached to the mount attachment holes 7D formed in the upper horizontal plate part 7B of the cab supporting extension beam 7 with the main body part 20A.

  As a result, each anti-vibration mount 20 has the main body portion 20A attached to the cab support portion 6 and the cab support overhanging beam 7 of the revolving frame 5, and the mounting screw 20B protruding upward is connected to the screw insertion hole of the floor plate 16 and the base frame body. 9 is attached to the cab 8 by being screwed into the mounting mounting holes 10A, 11A, 12A, 13A of the mounting bases 10, 11, 12, 13 forming the base 9 from below.

  In particular, the cab 8 of the small swivel excavator 1 has a narrow interior living space, and a screw tightening tool cannot be inserted into the rear side of the living space. Therefore, the vibration-proof mount 20 that supports the rear side of the cab 8 is disposed outside the cab 8 so that it can be easily bolted from the outside.

  Reference numeral 21 denotes a tipping restriction device provided between the turning frame 5 and the cab 8. The overturning restriction device 21 prevents the cab 8 from being displaced greatly. Here, the hydraulic excavator 1 travels in an unreasonable posture, for example, on a steep slope or the like, and may fall over when it is overturned. In the case of overturning, a large load acts on the cab 8 from the left side. At this time, each anti-vibration mount 20 connecting the revolving frame 5 and the cab 8 may be damaged by exceeding the normal stroke. Therefore, the overturning restricting device 21 prevents the cab 8 from being greatly displaced beyond the normal stroke of the anti-vibration mount 20, and prevents the respective anti-vibration mounts 20 from being damaged.

  That is, as shown in FIG. 7, the overturning restricting device 21 is provided between the cab supporting overhanging beam 7 constituting the revolving frame 5 and the left rear mounting base 12 of the base frame 9 constituting the cab 8. Yes. The overturn restricting device 21 is inserted into the through hole 7E provided in the cab supporting overhanging beam 7 and the through hole 7E with a gap from below, and the tip is screwed into the stopper mounting hole 12B of the left rear mounting base 12. The stopper bolt 22 that is attached, a washer 23 disposed on the head 22A of the stopper bolt 22, and a cylindrical collar 24 provided on the outer peripheral side of the stopper bolt 22 are roughly configured.

  The through hole 7 </ b> E of the cab supporting overhanging beam 7 is formed with a diameter larger than the collar 24 and smaller than the washer 23. In addition, the washer 23 comes into contact with the through hole 7E (the upper horizontal plate portion 7B of the cab supporting overhanging beam 7) from the lower side when the left side portion of the cab 8 is about to be displaced largely upward, and the head of the stopper bolt 22 is It functions as a stopper together with the portion 22A. Further, the collar 24 functions as a spacer that forms a buffer gap G between the upper horizontal plate portion 7B and the washer 23.

  Here, the buffering gap G formed between the upper horizontal plate portion 7B of the cab supporting extension beam 7 and the washer 23 is the same as that of the washer 23 when the vibration isolating mount 20 is displaced within the normal stroke range. The clearance dimension is set so that the washer 23 and the upper horizontal plate portion 7B come into contact with each other when the through hole 7E is separated from the normal stroke range, that is, when there is a possibility that the vibration isolating mount 20 is damaged. Yes.

  When the cab 8 is displaced such that the cab 8 falls to the right side, the overturn restricting device 21 configured in this way contacts the upper horizontal plate portion 7B of the cab supporting overhanging beam 7 provided with the hole 7E through the washer 23. Make contact. As a result, the overturning restriction device 21 can connect the left side portion of the cab 8 to the revolving frame 5 by the stopper bolt 22 and restrict the cab 8 from overturning.

  In addition, the fall restricting device 21 is disposed at the front side position of the left rear mounting base 12 by arranging the anti-vibration mount 20 at the rear side position of the left rear mounting base 12. Therefore, when the cab 8 is greatly displaced, the overturning restriction device 21 is engaged with the front side position of the upper horizontal plate portion 7B, which is considered weak in strength.

  Next, the reinforcing member 25 provided to increase the strength of the front side position of the upper horizontal plate portion 7B will be described.

  Reference numeral 25 denotes a reinforcing member according to the first embodiment which is provided between the cab-supporting extension beam 7 constituting the revolving frame 5 and the left side frame 5D. The reinforcing member 25 is provided across the front end of the upper horizontal plate portion 7B of the cab supporting overhanging beam 7 and the inner side surface 5D1 of the left side frame 5D, and between the cab supporting overhanging beam 7 and the left side frame 5D. The strength of the material is increased (reinforced).

  As shown in FIGS. 7 to 9, the reinforcing member 25 is provided separately from the cab supporting overhanging beam 7, and from the front end of the upper horizontal plate portion 7B of the cab supporting overhanging beam 7 to the inner side surface 5D1 of the left side frame 5D. Are formed as a plate body bent into an L-shape by a vertical plate portion 25A extending downward along the horizontal axis and a horizontal plate portion 25B bent from the lower end of the vertical plate portion 25A and extending to the front side.

  As shown in FIG. 9, the vertical plate portion 25A of the reinforcing member 25 includes an upper side portion 25A1 extending substantially horizontally in the left and right directions, a side portion 25A2 extending downward from the left end of the upper side portion 25A1, and the upper side. It is formed as a substantially right triangular plate body by an oblique side portion 25A3 connecting the right end of the portion 25A1 and the lower position of the side portion 25A2. Accordingly, the vertical plate portion 25A having a triangular shape can be transmitted in a state in which the stress is dispersed from the cab supporting overhanging beam 7 to the left side frame 5D. Moreover, since the hypotenuse 25A3 is curved in a concave arc shape, stress can be prevented from concentrating on the right end of the upper side 25A1 and the lower side of the side 25A2.

  The horizontal plate portion 25 </ b> B of the reinforcing member 25 extends forward with a cross-sectional area capable of transmitting a load (stress) acting on the reinforcing member 25. Even when the upper and lower dimensions of the reinforcing member 25 are limited by the height of the left side frame 5D, the horizontal plate 25B is bent from the lower end of the vertical plate 25A and extends to the front side. The length dimension in contact with the frame 5D can be extended.

  The reinforcing member 25 welds the upper side portion 25A1 of the vertical plate portion 25A to the front end of the upper horizontal plate portion 7B of the cab support overhanging beam 7, and connects the side portion 25A2 and the horizontal plate portion 25B of the vertical plate portion 25A to the left side. It is configured to be welded to the inner surface 5D1 of the frame 5D.

  Thereby, since the welding distance of the reinforcement member 25 with respect to the left side frame 5D can be lengthened, the attachment strength with respect to the left side frame 5D can be increased. In particular, when an upward load is applied to the upper horizontal plate portion 7B of the cab supporting overhanging beam 7 by the fall restricting device 21, stress concentrates on the lower end portion of the vertical plate portion 25A of the reinforcing member 25. The thin left side frame 5D is broken at the welding position. Therefore, by providing the horizontal plate portion 25B at the lower end portion of the vertical plate portion 25A and extending the welding distance in the horizontal direction, it is possible to prevent stress from being concentrated on the welding end point position of the lower end portion of the vertical plate portion 25A. it can.

  The hydraulic excavator 1 according to the first embodiment has the above-described configuration. Next, the operation thereof will be described.

  First, the operator gets into the cab 8 and sits on the driver's seat 17. By operating the traveling lever / pedal 19 in this state, the lower traveling body 2 can be driven to move the hydraulic excavator 1 forward or backward. An operator seated in the driver's seat 17 can perform the excavation work of earth and sand by operating the left and right working levers 18 to raise and lower the working device 4.

  Here, there is a possibility that the excavator 1 travels in an unreasonable posture or falls when it is operated, and a large load acts from the left side of the cab 8 when it falls. At this time, the cab 8 tends to be displaced so as to fall to the right. However, the excavator 1 according to the present embodiment is provided with the overturning restriction device 21 between the revolving frame 5 and the cab 8. Therefore, when the cab 8 is about to be displaced to the right, the head 22A of the stopper bolt 22 and the washer 23 of the overturning restricting device 21 come into contact with the periphery of the through-hole 7E of the cab support overhanging beam 7, and the displacement of the cab 8 Can be stopped. Thereby, the situation where each anti-vibration mount 20 is damaged can be prevented.

  Thus, according to the first embodiment, the cab support extending beam 7 that supports the rear portion of the cab 8 on the revolving frame 5 includes the vertical plate portion 7A extending in the left and right directions, and the vertical plate portion. The upper horizontal plate portion 7B projecting forward from the upper end portion of 7A and the lower horizontal plate portion 7C projecting forward from the lower end portion of the vertical plate portion 7A are bent into a J-shape or L-shape. The anti-vibration mount and the overturning restriction device are arranged on the upper horizontal plate portion 7B. In addition, a reinforcing member 25 that reinforces the space between the cab support overhanging beam 7 and the left side frame 5D between the front end of the upper horizontal plate portion 7B of the cab support overhanging beam 7 and the left side frame 5D. It is set as the structure which provides.

  Therefore, for example, even if the excavator 1 falls and the cab 8 is pushed from the left side to be largely displaced, the fall restricting device 21 attached to the cab 8 is engaged with the cab support extending beam 7 of the revolving frame 5. Thus, it is possible to restrict the cab 8 from being largely displaced. At this time, since a large load for tilting the cab 8 also acts on the cab support overhanging beam 7 via the overturning restricting device 21, the cab support overhanging beam 7 is fixed to the left side frame 5D. Stress concentrates on the part.

  However, in the first embodiment, the cab support overhanging beam 7 is provided with the reinforcing member 25 between the front end of the upper horizontal plate portion 7B and the left side frame 5D. By dispersing the stress transmitted from 7 to the left side frame 5D, the strength of the fixed portion between the cab support overhanging beam 7 and the left side frame 5D can be increased.

  As a result, the reinforcing member 25 disperses the stress even when the overturning restricting device 21 is provided on the front side of the upper horizontal plate portion 7B of the cab supporting overhanging beam 7 which has become structurally weak due to the free end. By increasing the strength (durability), damage to the fixing portion of the cab supporting overhanging beam 7 and the left side frame 5D, particularly the left side frame 5D, can be prevented, and durability and reliability can be improved. it can.

  The reinforcing member 25 includes a vertical plate portion 25A extending downward along the inner side surface 5D1 of the left side frame 5D from the front end of the upper horizontal plate portion 7B of the cab support extending beam 7, and the vertical plate portion 25A. It is formed as an L-shaped plate body by a horizontal plate portion 25B bent from the lower end and extending to the front side. Thereby, the vertical plate portion 25A of the reinforcing member 25 can disperse the stress transmitted from the cab support extending beam 7 to the left side frame 5D. In addition, since the horizontal plate portion 25B that is bent and extends forward is provided at the lower end of the vertical plate portion 25A, when the reinforcing member 25 is fixed to the left side frame 5D using welding means, the horizontal plate portion 25B. Therefore, the welding distance can be made longer and the attachment strength to the left side frame 5D can be increased.

  Further, the vertical plate portion 25A constituting the reinforcing member 25 includes an upper side portion 25A1 along the front end of the upper horizontal plate portion 7B of the cab support extending beam 7 and a side portion along the inner side surface 5D1 of the left side frame 5D. Since the triangular shape is formed by 25A2 and the oblique side portion 25A3 connecting the right end of the upper side portion 25A1 and the lower side of the side portion 25A2, the stress can be dispersed by this triangular shape. Thereby, even the small reinforcing member 25 can increase the strength between the cab support extending beam 7 and the left side frame 5D.

  Further, since the reinforcing member 25 is provided separately from the cab support overhanging beam 7 and the upper side portion 25A1 of the vertical plate portion 25A is fixed to the cab support overhanging beam 7 using welding means, the cab support overhanging beam 7 is used. In order to increase the strength between the beam 7 and the left side frame 5D, it is only necessary to weld the reinforcing member 25. Therefore, the existing excavator 1 can be easily handled.

  Next, FIG. 10 shows a second embodiment of the present invention. The feature of the present embodiment is that the reinforcing member is provided integrally with the cab support extending beam. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 10, reference numeral 31 denotes a cab support extension beam 31 according to the second embodiment, and the cab support extension beam 31 is substantially the same as the cab support extension beam 7 according to the first embodiment described above. , A long plate-like vertical plate portion 31A extending in the right direction, an upper horizontal plate portion 31B projecting forward from the upper end portion of the vertical plate portion 31A and extending substantially horizontally, and a lower end portion of the vertical plate portion 31A The upper horizontal plate portion 31B is formed with a mount mounting hole 31D and a through hole 31E.

  However, the cab support overhanging beam 31 according to the second embodiment has a cab support overhang according to the first embodiment in that a reinforcing member 32 described later is integrally provided on the upper horizontal plate portion 31B. It is different from the beam 7.

  Reference numeral 32 denotes a reinforcing member according to the second embodiment provided on the cab supporting overhanging beam 31. The reinforcing member 32 is substantially the same as the reinforcing member 25 according to the first embodiment. The vertical plate portion 32A is formed as a substantially right triangle plate, and the front side is bent from the lower end of the vertical plate portion 32A. It is formed as a plate body that is bent in an L shape by a horizontal plate portion 32B that extends in the direction.

  However, the reinforcing member 32 according to the second embodiment is different from that of the first embodiment in that the vertical plate portion 32A is integrally provided at the front end of the upper horizontal plate portion 31B of the cab supporting overhanging beam 31. This is different from the reinforcing member 25. That is, the vertical plate portion 32A of the reinforcing member 32 is formed by bending and extending the front end of the upper horizontal plate portion 31B downward.

  Thus, also in the second embodiment configured as described above, the reinforcing member 25 is provided between the cab supporting overhanging beam 31 and the left side frame 5D in substantially the same manner as in the first embodiment described above. Therefore, the strength of the fixed portion between the cab support overhanging beam 31 and the left side frame 5D can be increased. In particular, in the second embodiment, since the reinforcing member 25 is integrally provided at the front end of the upper horizontal plate portion 31B of the cab support overhanging beam 31, it is possible to reduce the number of parts, simplify the welding operation, and the like. Productivity can be improved.

  In the first embodiment, the extended beam 7 for supporting the cab is projected to the front from the long plate-like vertical plate portion 7A extending in the left and right directions and the upper end portion of the vertical plate portion 7A. Illustrated is a case where the upper horizontal plate portion 7B extending horizontally and the lower horizontal plate portion 7C protruding forward from the lower end portion of the vertical plate portion 7A are bent into a J shape or L shape. is doing.

  However, the present invention is not limited to this. For example, the cab supporting overhanging beam 41 according to the modification shown in FIG. 11 may be used. In other words, the cab supporting overhanging beam 41 according to the modified example includes a long plate-like vertical plate portion 41A extending in the left and right directions, and an upper side projecting forward from the upper end portion of the vertical plate portion 41A and extending substantially horizontally. The horizontal plate portion 41B and the lower horizontal plate portion 41C protruding rearward from the lower end portion of the vertical plate portion 41A are formed in a Z shape, and the reinforcing member 25 is fixed to the upper horizontal plate portion 41B. Also good. This configuration can be similarly applied to the second embodiment.

  Moreover, in each embodiment, the case where the anti-vibration mount 20 is provided between the revolving frame 5 and the cab 8 at the four corner positions located on the left front, right front, left rear, and right rear of the cab 8 is described. Explained with an example. However, the present invention is not limited to this, and for example, five or more anti-vibration mounts 20 may be provided between the revolving frame 5 and the cab 8.

  Furthermore, in each embodiment, the crawler type hydraulic excavator 1 was described as an example of the construction machine. However, the present invention is not limited to this, and may be applied to, for example, a hydraulic excavator provided with a wheel-type lower traveling body. Further, it can be widely applied to other construction machines such as a hydraulic crane, a wheel loader, and a tractor.

1 Excavator (construction machine)
5 Turning frame (body frame)
5A Bottom plate (center frame)
5B, 5C Work device mounting plate (center frame)
5D, 5E Side frame 5D1 Inner side surface 5F Overhang beam 6 Cab support portion 7, 31, 41 Overload beam for cab support 7A, 31A, 41A Vertical plate portion 7B, 31B, 41B Upper horizontal plate portion 7C, 31C, 41C Lower horizontal Plate part 8 Cab 17 Driver's seat 20 Anti-vibration mount 21 Tilt restricting device 25, 32 Reinforcing member 25A, 32A Vertical plate part 25A1 Upper side part 25A2 Side part 25A3 Oblique side part 25B, 32B Horizontal plate part

Claims (3)

A vehicle body frame comprising a center frame, a side frame, and an extension beam, a cab support portion provided on the front side, and one of the extension beams formed as an extension beam for cab support;
A cab provided on the upper side of the cab support portion of the vehicle body frame and the cab support extension beam, and defining a living space for the operator inside,
An anti-vibration mount provided between the cab and the cab support portion of the vehicle body frame and a cab support extending beam and the cab;
A cab support portion of the vehicle body frame, a cab support overhanging beam, and a tumbling restricting device that restricts the cab from being largely displaced beyond the normal stroke of the vibration-proof mount. In construction machinery
The extension beam for supporting the cab is formed by a vertical plate portion extending in the left and right directions and a horizontal plate portion protruding forward from an upper end portion of the vertical plate portion and provided with the anti-vibration mount and the overturn regulating device,
The extension beam for supporting the cab is provided with a reinforcing member that is positioned between the front end of the horizontal plate portion and the side frame and reinforces the extension between the extension beam for supporting the cab and the side frame. Construction machinery characterized by that.   The reinforcing member extends from the front end of the horizontal plate portion of the extension beam for supporting the cab downward along the inner surface of the side frame, and bends from the lower end of the vertical plate portion and extends to the front side. The construction machine according to claim 1, wherein the construction machine is formed as an L-shaped plate body by a horizontal plate portion.   The vertical plate portion constituting the reinforcing member includes an upper side portion along the front end of the horizontal plate portion, a side portion along the inner side surface of the side frame, and a hypotenuse that connects the upper side portion and the side portion. The construction machine according to claim 2, wherein the construction machine is formed in a triangular shape by a portion.

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