JP4920570B2 - Cab reinforcement structure in construction machinery - Google Patents

Description

  The present invention relates to a cab reinforcement structure in a construction machine, and more particularly to a cab reinforcement structure in a small-sized construction machine such as a small turning hydraulic excavator.

  In general, a construction machine such as a hydraulic excavator is provided with a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a front and rear side of the upper revolving body that can be moved up and down. The work attachment is generally constituted, and excavation work such as earth and sand is performed using this work attachment.

Further, the upper swing body of the excavator is provided with a counterweight provided on the rear end side to balance the weight with the front, and further serves as a base for protecting the living space of the operator and improving the operating environment. The thing which provided the cab in the one side of a turning frame is known (for example, refer patent document 1, patent document 2).
JP 2002-339406 A Japanese Patent No. 3671790

  However, the cab and the counterweight in the hydraulic excavators described in Patent Document 1 and Patent Document 2 are provided independently on the cab floor surface attached to the revolving frame. Therefore, when the aircraft falls and a large impact load is applied to the cab, the cab must be prevented from being deformed or damaged by the strength of the entire cab. For this reason, it is necessary to increase the strength of the members constituting the cab, and there is a problem that the cost is increased.

  Therefore, the technology to be solved to provide a cab reinforcement structure in construction machinery that can minimize deformation and breakage of the cab even when the aircraft falls and a large impact load is applied to the cab. The present invention aims to solve this problem.

The present invention has been proposed to achieve the above object, and the invention according to claim 1 includes a cab mounted on a revolving frame of a fuselage, and a rear wall plate of the cab from a rear end portion of the revolving frame. In a construction machine comprising a counterweight installed at the rear of the cab so as to rise upward along the outer surface, the lower portion of the counterweight is attached to the turning frame, and the upper portion of the counterweight is fixed to the cab by a fixing means. Provided is a cab reinforcing structure in a construction machine that is attached to an intermediate position in the vertical direction on the rear side surface.

  According to this configuration, the counterweight with the upper portion attached to the middle position on the rear side of the cab in the vertical direction functions as a reinforcing material that supports the middle position on the rear side of the cab in the vertical direction. When a load is applied, a part of the impact load is absorbed on the counterweight side to minimize deformation of the entire cab.

  According to a second aspect of the present invention, the fixing means includes an anchor member projecting from one of the rear side surface of the cab or the counterweight, and the rear side surface of the cab on the other side corresponding to the anchor member or the counter. A locking portion provided on a weight, and the locking portion is provided with a locking hole through which the tip of the anchor member is penetrated and capable of hooking and holding the penetrating tip at a hole edge. A cab reinforcing structure in a construction machine is provided.

  According to this configuration, when the distal end portion of the anchor member is inserted and penetrated into the locking hole, and the distal end portion of the anchor member is hooked on the hole edge of the locking hole after the penetration, the space between the rear surface of the cab and the counterweight is set. Are held together.

  According to a third aspect of the present invention, the fixing means includes a bolt projecting to the counterweight side through the rear side surface of the cab, and a screw hole provided on the counterweight side corresponding to the bolt. Provided is a cab reinforcing structure in a construction machine that fixes a space between the rear surface of the cab and the counterweight by screwing the bolt and the screw hole.

  According to this configuration, when the bolt is screwed into the screw hole on the counterweight side from the inside of the rear side surface of the cab through the rear side surface, the screw between the bolt and the screw hole causes a gap between the rear side surface of the cab and the counterweight. Is fixed.

  According to the first aspect of the present invention, the counterweight having the upper portion attached to the middle position on the rear side of the cab functions as a reinforcing material that supports the middle position on the rear side of the cab. When a large impact load is applied from the outside due to a fall or the like, the counterweight can absorb the impact load and minimize deformation and breakage of the cab, thereby improving safety. In addition, since it is possible to use inexpensive materials while minimizing the strength of the members constituting the cab, it is also possible to reduce costs.

Since the counterweight is attached to the height of the middle position of the cab, the strength of the cab body is not so great compared to the conventional structure where only the lower surface of the cab is supported by the swivel frame. The deformation of the cab against the impact load can be suppressed, which can contribute to cost reduction. Further, since and a counterweight which from the rear portion is placed at the rear of the cab so as to rise upward along the wall plate outer surface after said cab above the revolving frame, with weight balance of the working attachment, By covering the engine, the hydraulic pump, and the heat exchange device from the rear side, the safety of the devices can be ensured.

This invention, the bond holding the cab after the side and the counterweight, it is possible to easily carry out the mutual coupling with the hole edge of the anchor member and the locking hole, in addition to the above effects, the assembling workability Improvements can also be expected. In addition, the counterweight is configured to rise upward from the rear end of the swivel frame along the outer surface of the rear wall plate of the cab, so that the weight balance with the work attachment is achieved, and the engine, hydraulic pump The safety of the devices can be ensured through covering the heat exchange device from the rear side.

According to the third aspect of the present invention, the coupling and fixing to the rear surface of the cab can be easily performed by screwing the bolt and the screw hole, so that an improvement in assembly workability can be expected.
In addition, the counterweight is configured to rise upward from the rear end portion of the slewing frame along the outer surface of the rear wall plate of the cab, so that the weight balance with the work attachment is achieved, and the engine, hydraulic pressure The device can be safely held through covering the pump and the heat exchange device from the rear side.

  In order to achieve the purpose of providing a cab reinforcement structure in a construction machine that can minimize deformation and breakage of the cab even when the aircraft falls and a large impact load is applied to the cab, In a construction machine comprising a cab mounted on a swivel frame of a machine body and a counterweight installed behind the cab, a lower part of the counterweight is attached to the swivel frame, and an upper part of the counterweight is fixed to the cab by a fixing means. This was realized by adopting a cab reinforcement structure in a construction machine that was attached to the middle position on the rear side of the rear side.

  Hereinafter, the cab reinforcing structure in the construction machine of the present invention will be described with reference to preferred embodiments. FIG. 1 is a side view of a small swing type small excavator 1 to which the present invention is applied, FIG. 2 is a rear perspective view of the small excavator 1, and FIGS. 3 and 4 are enlarged main parts showing a fixing portion of the counterweight 18. FIG.

  As shown in FIGS. 1 to 4, the small hydraulic excavator 1 is roughly configured by a crawler-type lower traveling body 2 that can be self-propelled and an upper revolving body 3 that is rotatably mounted on the lower traveling body 2. A work attachment 4 is provided on the front side of the upper swing body 3.

  The work attachment 4 includes a lower boom 6 attached to a turning frame 5 described later so as to be able to move up and down, an upper boom 7 attached to the distal end side of the lower boom 6, and an arm attached to the distal end side of the upper boom 7. A support rod 8, an arm 9 attached to the distal end side of the arm support member 8, a bucket 10 attached to the distal end side of the arm 9, and a link rod that connects between the lower boom 6 and the arm support member 8. 11, a boom cylinder 12, an arm cylinder 13, a bucket cylinder 14, and an offset cylinder 15.

  The upper swing body 3 is installed on the lower traveling body 2 via a swing mechanism 16 so as to be swingable. In addition to the swing frame 5, the cab 17 and the counterweight 18, a fuel tank, a hydraulic oil tank, an engine (not shown) are provided. It is comprised by the exterior cover etc.

  The cab 17 is located on the left side of the work attachment 4 and is provided on the turning frame 5. A driver seat (not shown) is provided inside the cab 17, and an operator is seated on the driver seat. The operation is performed. Further, the cab 17 is formed as a box-shaped space space in which the upper and lower surfaces, the left and right surfaces, and the front and rear surfaces are closed by wall plates and doors.

  The counterweight 18 rises upward from the rear end portion of the revolving frame 5 along the outer surface of the rear wall plate 19 of the cab 17 to balance the weight with the work attachment 4 and also includes an engine, a hydraulic pump, and a heat exchanger (not shown). The device is covered from the rear side. The lower part of the counterweight 18 is attached to the rear end of the revolving frame 5, and the upper part is attached to the intermediate position in the vertical direction of the rear wall plate 19 of the cab 17 by fixing means 20.

  Mounting leg portions 18 a that protrude toward the rear wall plate 19 of the cab 17 are formed on the left and right sides of the upper portion of the counterweight 18. Further, a recess 22 for receiving the fixing bracket 21 of the fixing means 20 is formed on the upper surface of the counterweight 18. Further, screw holes 24 and 24 are formed in the inner peripheral surface 23 of the recess 22.

  The counterweight 18 is positioned and fixed by means (not shown) with the lower contact surface 18b in contact with the rear end surface of the revolving frame 5, and the front surface of the mounting leg 18a is attached to the rear wall plate 19. Attached to the intermediate position on the outer surface in the vertical direction and fixed between the cab 17 and the counterweight 18 by the fixing means 20.

  The fixing bracket 21 is an L-shaped iron plate material having a first plate portion 21a and a second plate portion 21b provided by bending an intermediate portion thereof at a substantially right angle. A pair of mounting holes 29, 29 through which the bolts 25, 25 are passed are formed in the first plate portion 21 a of the fixing bracket 21. On the other hand, a circular locking hole 26 is formed in the second plate portion 21b, and as will be described later, an anchor member 27 protruding rearward from the rear wall plate 19 of the cab 17 is provided with the locking member 26. The hole 26 is inserted and locked.

  As shown in FIG. 3, the fixing bracket 21 has a mounting hole 29 when the second plate portion 21 b faces the front side and the first plate portion 21 b is brought into contact with the inner peripheral surface of the recess 22. , 29 correspond to the screw holes 24, 24, and bolts 25, 25 are inserted into the mounting holes 29, 29 and screwed into the screw holes 24, 24. The first plate portion 21a is handled in a state of being fixed to the counterweight 18 in advance.

  As shown in FIG. 4, the anchor member 27 corresponds to the locking hole 26 of the fixing bracket 21, and is a metal pin-like material provided at the middle position in the vertical direction of the rear wall plate 19 in the cab 17. It is. The anchor member 27 has one end (base end) fixed to a frame (not shown) of the cab 17 and the other end (free end) extended rearward from the rear wall plate 19 of the cab 17. In addition, a disc-shaped flange portion 27a is integrally provided at the distal end portion on the other end side. The outer diameter of the flange portion 27a is formed slightly smaller than the inner diameter of the locking hole 26. Therefore, the flange portion 27 a can penetrate the locking hole 26 and protrude to the back surface side (inside of the recess 22) of the fixing bracket 21, and the flange portion 27 a can be used as a hole edge of the locking hole 26 on the back surface side. It has a structure that can be hung.

  And the fixing means 20 comprised in this way is used as follows. First, when the rear end surface of the swivel frame 5 is brought into contact with the counterweight 18 and the upper portion of the counterweight 18 is brought into contact with the rear wall plate 19 of the cab 17, The part 27 a) is inserted into the locking hole 26. Further, the flange portion 27a of the anchor member 27 protrudes to the back surface side of the second plate portion 21b at the position where the front surface of the mounting leg portion 18a is in contact with the rear wall plate 19.

  When the force that supports the counterweight 18 from below is released in this state, the counterweight 18 is slightly lowered by its own weight, and the flange portion 27a is hooked on the edge of the locking hole 26 so that the upper portion of the counterweight 18 is covered. The rear wall plate 19 in the cab 17 can be fixed at a lower intermediate position.

  As described above, in the small excavator 1 according to the present invention, the upper portion of the counterweight 18 is attached to the intermediate position in the vertical direction of the rear wall plate 19 in the cab 17 by the fixing means 20, and the counterweight 18 is a reinforcing material for the cab 17. It has become. For this reason, as in the conventional structure in which only the lower surface of the cab is supported by the revolving frame, when a large impact load from the outside is directly applied to the cab, the cab is greatly deformed and damaged in comparison with the present invention. Even when the airframe falls and a large impact load is applied to the cab 17, a part of the impact load is absorbed by the counterweight 18, and deformation and breakage of the cab 17 can be minimized. In addition, it is possible to reduce costs by minimizing the strength of the members constituting the cab 17 and using inexpensive materials.

  In the structure of the above embodiment, the locking hole 26 is provided on the counterweight 18 side and the anchor member 27 is provided on the cab 17 side of the locking piece 26 and the anchor member 27 constituting the fixing means 20. However, a structure in which the locking hole 26 is provided on the cab 17 side and the anchor member 27 is provided on the counterweight 18 side may be employed.

  FIG. 5 shows a modification of the fixing means. The fixing means 30 shown in FIG. 5 includes a mounting bolt 31 protruding from the cab 17 side and a screw hole 32 provided on the front surface of the mounting leg portion 18a of the counterweight 18. Reference numeral 33 denotes a washer attached to the attachment bolt 31.

  The mounting bolt 31 passes through a through hole 35 provided in the cab frame 34 of the cab 17 and a through hole 36 provided in the rear wall plate 19, and extends from the inside of the cab 17 toward the rear rear side of the cab 17. Protruding. On the other hand, the screw holes 32 of the mounting legs 18a are provided corresponding to the through holes 35 and 36, and the mounting bolts 31 can be screwed together.

  The fixing means 30 configured as described above is used as follows. First, the rear end surface of the revolving frame 5 and the counterweight 18 are abutted and positioned, and the mounting leg portion 18a that is the upper portion of the counterweight 18 is brought into contact with the rear wall plate 19 of the cab 17 so that the cab 17 side The through holes 35 and 36 and the screw holes 32 on the counterweight 18 side correspond to each other. Next, the mounting bolt 33 is inserted into the screw hole 32 through the through holes 35 and 36 from the inside of the cab 17, and the mounting bolt 33 is screwed into the screw hole 32 to tighten between the cab 17 and the counterweight 18. The upper portion of the counterweight 18 can be fixed to the intermediate position of the outer surface of the rear wall plate 19 in the cab 17 in the vertical direction.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

The side view of the small hydraulic excavator to which this invention is applied. The rear perspective view of a small hydraulic excavator. The principal part enlarged view which shows the fixed part of a counterweight. The principal part enlarged view which shows the fixed part of a counterweight. The principal part enlarged view which shows one modification of a fixing means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Small hydraulic excavator 2 Lower traveling body 3 Upper turning body 4 Work attachment 5 Turning frame 17 Cab 18 Counterweight 18a Mounting leg 19 Rear wall plate 20 Fixing means 21 Fixing metal fitting 26 Locking hole 27 Anchor member 27a Anchor part 30 Fixing means 31 Mounting bolt 32 Screw hole 34 Cab frame 35 Through hole 36 Through hole

Claims (3)

In a construction machine comprising a cab mounted on a swivel frame of a fuselage, and a counterweight installed at the rear of the cab so as to rise upward from a rear end portion of the swivel frame along an outer surface of a rear wall plate of the cab.
A cab reinforcing structure in a construction machine, wherein a lower part of the counterweight is attached to the revolving frame, and an upper part of the counterweight is attached to a middle position in the vertical direction of the rear side surface of the cab by a fixing means. The fixing means includes an anchor member projecting from one of the rear side surface of the cab or the counterweight, and a locking portion provided on the rear side surface of the cab on the other side or the counterweight corresponding to the anchor member. in it, claim the engaging portion is the tip of the anchor member is penetrated, and characterized by comprising providing a stop capable of holding the locking hole over the through-threaded tip hole edge and The cab reinforcing structure in the construction machine according to 1 .   The fixing means includes a bolt projecting to the counterweight side through the rear side surface of the cab, and a screw hole provided on the counterweight side corresponding to the bolt, and the bolt and the screw hole are screwed. The cab reinforcing structure in a construction machine according to claim 1, wherein the cab rear side surface and the counterweight are fixed together.

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