JP2010133192A - Handrail of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the vibration and oscillation of a handrail body caused by the vibration or the like of a vehicle to enhance the attaching strength thereof. <P>SOLUTION: A mirror unit 40 attached to a curved part 31a of the handrail body 31 constituting a handrail 30 is attached with a mirror 41 to a support arm 42, the support arm 42 is connected to a damper member 45, the damper member 45 is fixed with a tip of a connection rod 44 from the handrail body 31, the damper member 45 is constituted of a cylindrical body 46 including a sliding body 48 slidable along an inner face thereof, the support arm 42 is connected to the sliding body 48, elastic members 50 are provided at both ends of the sliding body 48 and sandwiched, both the elastic members 50 are compressed to be attached to the cylindrical body 46 in a state that a prescribed spring force acts thereon, and a cap 49 is engaged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a handrail of a construction machine that is provided in a construction machine such as a hydraulic excavator and is used as a clue when ascending and descending from an upper swing body to a tank or a building, and particularly relates to a handrail with a mirror attached thereto. Is.

  A construction machine such as a hydraulic excavator is configured by mounting an upper swing body on a lower traveling body via a swing device. The upper swing body is provided with a cab and is equipped with working means. In addition to these, tanks such as a fuel tank and a hydraulic oil tank are installed, and a building constituting a machine room is also provided. The driver's cab is provided with handrails for getting on and off, but the steps on the opposite side of the driver's cab across the working means are to be able to ascend and descend on the upper swing body. A handrail is provided to make it safe and easy to ascend and descend using this step.

As the handrail, for example, a configuration disclosed in Patent Document 1 is widely used. That is, a handrail body is formed from a bent pipe, and one end side of the handrail body is connected and fixed to a revolving frame of the upper revolving body using a bolt, and an approximately arc shape is formed upward from the fixed portion. The other end is fixed to the upper surface of the tank with a bolt. A mirror can be attached to the handrail in order to ensure a visual field behind the cab.
JP 2007-46405 A

  Here, even if the operator or the like is standing on the tank, in order to be able to grip the handrail without difficulty, the operator should project it upwards so that it is higher than the height of the operator's waist. Yes. For this reason, when performing work such as vibration of a vehicle or excavation, the handrail body constituting the handrail greatly vibrates or swings. As a result, the connecting / fixing portions at both ends of the handrail body Stress will be concentrated on.

  To fix the end of the handrail body, the bolt seat is usually fixed to the wall surface of the swivel frame, tank, etc. by means such as welding, and the end of the handrail body is flattened, and the bolt insertion hole is drilled. It is generally installed and fastened to the bolt seat. Therefore, as described above, when the handrail body vibrates or swings, a large impact load may repeatedly act on the welded portion of the bolt seat and the crack may occur. Moreover, when a mirror is mounted on the handrail body, the weight of the mirror and the support arm of the mirror acts on the handrail body, so that the inertial load increases accordingly, and a larger impact load is applied. Acts on both fixed parts of the handrail body. As a result, there is a problem that bolts, bolt seats, etc. are damaged or deteriorated early.

  The present invention has been made in view of the above points, and an object of the present invention is to suppress the vibration or swinging of the handrail body due to the vibration of the vehicle or the like and to improve the mounting strength thereof. is there.

  In order to achieve the above-described object, the present invention is provided by fixing both ends of a handrail body made of a bent pipe to an upper swing body of a construction machine, and connecting the support rail to the handrail body. A handrail having a mirror mounted thereon, wherein a damper member extends from the handrail body, and the support arm of the mirror is connected to the damper member. .

  Steps are provided to allow workers etc. to ascend and descend from the upper swing body to the tank upper surface and on the building, but the handrail is gripped when the operator ascends and descends through this step It is. Therefore, one end of the handrail body constituting the handrail is fixed to the frame of the upper swing body, and extends upward while curving toward the step direction, that is, toward the rear of the vehicle. In general, the other end is fixed to the upper surface of a tank installed on the upper rotating body so as to be folded downward from the upper end. Then, the protruding end of the handrail extends to a height position where the operator can easily grip it while standing on the tank. For this reason, when the vehicle vibrates, this vibration is transmitted from the both end fixing portions of the handrail body to the entire handrail, and swings or vibrates in the left-right direction (hereinafter simply referred to as vibration).

  In the present invention, a mirror attached to the handrail is used, and the function as a dynamic damper having the handrail as a main vibrator and the mirror as a sub-vibrator is exhibited to absorb the vibration of the handrail. . That is, a mirror having a constant mass is connected to a damper member having a predetermined spring constant, and this damper member is attached to a hand rail as a main vibration body as a sub vibration body. When an external force acts on the handrail that is the main vibrator, this external force passes through the handrail and is transmitted to the mirror that is the sub-vibrator, but the external force acting on the handrail is canceled out. Vibrate in the opposite direction. Thereby, it is possible to attenuate the vibration of the handrail which is the main vibrating body.

  As a specific configuration of the damper member, for example, a sliding body is mounted inside a cylindrical body such as a cylindrical shape, and the sliding body is mounted so as to be slidable in the axial direction of the cylindrical body. The movable body is clamped by elastic members from both sides, and the support arm of the mirror is connected to the sliding body. The elastic member has a predetermined spring constant, and this elastic member is mounted so that a uniform spring force acts on both sides of the sliding body. The elastic member can be made of rubber or a metal having a spring property, and a viscous fluid can also be used.

  Here, the cylindrical body constituting the damper member is arranged so as to vibrate in a direction to cancel this vibration with respect to the vibration direction of the handrail body. However, the direction of the mirror is determined in relation to the operator's cab installed on the upper swing body in the construction machine. For this reason, the direction of the damper member and the direction of the mirror may not coincide with each other, but the relative direction between the cylinder and the mirror can be obtained by bending the support arm interposed therebetween in a predetermined direction. Adjustments can be made.

  The cross-sectional shape of the cylinder in the damper member is generally circular, but may be a quadrilateral or other polygonal shape. By forming the cylindrical body into a bottomed cylindrical shape and detachably attaching the cap to the end on the opening side, the elastic member can be easily assembled and removed. And since the support arm of the mirror is connected to the damper member, for example, when an operator or the like ascends or descends to the upper swing body, a situation may occur in which the support arm is gripped and weight is applied. is there. Even in such a case, in order not to damage the elastic member, the cylindrical body can be configured to be provided with a stopper at a position where the damper action is not hindered.

  Even if the handrail body vibrates due to the vibration of the vehicle provided with the handrail, the vibration can be suppressed or attenuated by the action of the dynamic damper using the mirror as a mass. A sufficiently high mounting strength is given to the fixed portion, and the durability is improved.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a configuration of a hydraulic excavator as an example of a construction machine. Needless to say, the present invention is not limited to the hydraulic excavator.

  In the figure, reference numeral 1 denotes a hydraulic excavator, and the hydraulic excavator 1 includes a lower traveling body 2 having left and right traveling means composed of crawler belts. 4 is installed so that turning is possible. Excavation working means 11 is attached to the revolving body frame 10 of the upper revolving structure 3 at a substantially central position on the front side thereof, and a cab 12 is located on one side of the excavation working means 11, specifically, on the left side. Is provided. A building 13 constituting a machine room is installed at a rear position of the cab 12 and the attachment portion of the excavation work means 11. Further, a counterweight 14 is attached to the rearmost position of the upper swing body 3.

  2 and 3 show the configuration of the upper revolving unit 3 on the side opposite to the cab 12 with the excavation work means 11 in between, specifically, the right side portion. In the figure, reference numeral 15 denotes a fuel tank, and 16 denotes a hydraulic oil tank. In the revolving structure frame 10, the fuel tank 15 is arranged on the front side, and the hydraulic oil tank 16 is arranged in the rear position. When replenishing fuel or performing maintenance of various devices provided in the building 13, it is necessary to ascend and descend from the fuel tank 15 onto the building 13. These parts are high places, and steps are provided as scaffolds for ascending and descending to such high places.

  The illustrated step is an example, but in this example, a lower step 17 is provided so as to project forward from the revolving body frame 10, and a middle step 18 is formed on the upper portion of the tool box 19. Further, a wall surface portion 20 is erected on the side portion of the fuel tank 15, and an upper step 21 is provided so as to protrude from the wall surface portion 20. As described above, the handrail 30 is provided in order to ensure the stability of the body when an operator or the like goes up and down the steps 17, 18, and 21 provided in three stages.

  The handrail 30 is configured by fixing end connection portions 32a and 32b provided at both ends of a handrail body 31 formed of a bent metal pipe at predetermined positions. One end 32a of the handrail body 31 is fixed to the front surface portion of the revolving structure frame 10, and extends upward from the revolving structure frame 10 and forms a curved portion 31a that is curved in the direction of the step. ing. At the upper position of the wall surface portion 20 attached to the fuel tank 15, the folded portion 31 b is folded back so as to face the straight portion to become the vertical portion 31 c, and the end portion of the vertical portion 31 c is fixed to the upper end portion of the wall surface portion 20. ing. The handrail body 31 is disposed in the front-rear direction in the vicinity of the rightmost end of the revolving structure frame 10.

  Next, the structure of the fixing portions at both ends of the handrail 30 is as shown in FIG. That is, the handrail body 31 is made of a metal pipe, and the end connecting portions 32a and 32b are flattened. A bolt seat 33 is fixed to the revolving body frame 10 and the wall portion 20 to which the handrail main body 31 is fixed by welding, and the bolt 34 is inserted into the bolt insertion hole of the handrail main body 31 to be bolted. The seat 33 is fastened. The mirror unit 40 is attached to the handrail body 31 of the handrail 30 mounted on the upper swing body 3 in this way. As apparent from FIGS. 4 and 5, the mirror unit 40 includes a mirror 41 coupled to a support arm 42, and the mirror 41 can be adjusted in angle around the axis and in the vertical direction with respect to the support arm 42. It has become.

  A clamp member 43 is attached to the curved portion 31 a of the handrail body 31 constituting the handrail 30. A connecting rod 44 is fixed to the clamp member 43, a damper member 45 is connected to the tip of the connecting rod 44, and the support arm 42 of the mirror 41 is supported by the damper member 45. As shown in FIGS. 6 and 7, the damper member 45 includes a metal cylinder 46 having a substantially cylindrical shape, and is configured from a bottomed cylinder having one end closed and the other end opened. The tip of the connecting rod 44 is fixed by means such as welding. A slit groove 47 is formed at a position from the opening end side to the middle of the cylindrical body 46. A sliding body 48 is provided inside the cylindrical body 46, and a cap 49 is fitted to the end thereof. The sliding body 48 includes an arm fixing portion 48a connected to the support arm 42 from the mirror 41, and sliding portions 48b and 48b formed by increasing the diameters of both ends of the arm fixing portion 48a. The portions 48 b and 48 b are configured to slide along the inner surface of the cylindrical body 46. Elastic members 50 and 50 are interposed between the end surfaces of the sliding portions 48 b and 48 b, the closed end portion of the cylindrical body 46, and the inner surface of the cap 49.

  The elastic member 50 is made of rubber or the like having a predetermined spring constant and is mounted in a compressed state. The sliding body 48 connected to the mirror 41 can reciprocate in the axial direction of the cylindrical body 46. When the sliding body 48 slides, the elastic member 50 located on the front side in the moving direction is compressed. Will be. That is, the mirror 41 vibrates in the axial direction of the cylindrical body 46 constituting the general damper member 45. Since the support arm 42 is connected to the slide body 48, the movement range of the slide body 48 is restricted between the groove end portion of the slit groove 47 of the cylindrical body 46 and the end portion of the cap 49. Thus, these are stoppers that regulate the movement stroke of the sliding body 48.

  The support arm 42 of the mirror 41 extends to the inside of the cylindrical body 46 through the slit groove 47 and is connected to the arm fixing portion 48 a of the sliding body 48. Here, the slit groove 47 has a groove width having a dimension slightly larger than the diameter dimension of the support arm 42. As a result, the support arm 42 is prevented from rotating without being displaced in the direction around the axis of the cylindrical body 46, and the mirror 41 is prevented from being tilted or displaced.

  The present embodiment is configured as described above, and the excavator 1 is driven by the excavation work means 11 to perform operations such as excavation of earth and sand, and travel and turn by the lower traveling body 2. The turning operation of the upper swing body 3 by the device 4 is performed. During this time, the entire vehicle vibrates, and particularly when excavating earth and sand, a very large impact load acts on the entire vehicle. Thus, when vibration occurs in the vehicle, this vibration is transmitted to the handrail 30 and the handrail body 31 vibrates. In particular, when the impact load repeatedly acts, the handrail 30 will vibrate or oscillate greatly. As a result, an excessive load may repeatedly act on the lower and upper end coupling portions 32a and 32b of the handrail body 31 to cause damage such as a crack in the welded portion of the bolt seat 33. is there.

  Here, the handrail 30 is provided so as to face in the front-rear direction of the upper swing body 3, and the vibration of the handrail main body 31 due to the vibration of the vehicle is caused by the vibrations at both ends as shown by arrows B in FIG. The reciprocating motion is performed so as to swing substantially in the left-right direction around the fixed portion. The handrail body 31 is mounted with a mirror unit 40 having a damper member 45 provided at the tip of a connecting rod 44 having a predetermined length, and vibration is transmitted to the mirror unit 40 via the handrail body 31. Communicated. Therefore, when the handrail body 31 is the main vibrator, the mirror unit 40 is a sub-vibrator. As a result, it functions as a dynamic damper that absorbs the vibration of the main vibrating body by the vibration of the sub-vibrating body.

  That is, since the hand rail body 31 as the main vibration body is formed of a metal pipe, the hand rail body 31 has a predetermined spring constant and a predetermined mass. As a result, the hand rail body 31 has a natural angular frequency. Thus, it vibrates in the arrow direction B in FIG. Since this vibration is transmitted to the mirror unit 40 attached to the handrail main body 31, this mirror unit 40 becomes a sub-vibration body. A cylindrical body 46 constituting a damper member 45 provided at the tip of a connecting rod 44 extending from the handrail body 31 is connected to the mirror unit 40, and this damper member 45 is a spring constant of the elastic member 50. Vibrates at a natural angular frequency based on the above, and by directing the cylindrical body 46 in a direction in which the damping function is exhibited, the handrail body 31 vibrates in a direction to cancel the vibration. As a result, the vibration of the handrail body 31 is suppressed and the vibration can be controlled.

  As described above, the operation of the hydraulic excavator 1 is performed by using the mirror unit 40 attached to the handrail body 31 as a sub-vibration body and vibrating the handrail body 31 as a main vibration body in a direction to suppress or absorb vibration. In particular, during the excavation work of earth and sand, the impact load transmitted to the handrail 30 is attenuated or suppressed by the action of the mirror unit 40 as a sub-vibration body. For this reason, the welded part of the bolt seat 34 for fixing both ends of the handrail body 31 and the bolt 34 are not damaged, and the service life of them can be extended.

  As described above, since the mirror 41 is sandwiched between the elastic members 50 and 50, the mirror 41 vibrates even though it is minute during the operation of the hydraulic excavator 1, and for the operator located in the cab 12, the mirror 41. Is difficult to see. However, the operator visually observes the mirror 41 for the safety confirmation of the surroundings before the operation of the hydraulic excavator 1 is started. During operation, excavation of the earth and sand with particularly strong vibration is performed. Since the working means 11 is watched and the mirror 41 is not normally seen, even if the mirror 41 vibrates, it does not become a special problem.

  Here, the vibration direction of the handrail 30 as the main vibration body is constant, and the direction of the cylindrical body 46 constituting the dynamic damper is caused to vibrate in a direction that cancels this vibration with respect to the vibration direction of the handrail body 31. For this purpose, the connecting rod 44 extends in a predetermined direction. The mirror 41 is for obtaining a rear visual field required by an operator seated in the cab 12 installed in the upper swing body 3. The mirror 41 is mounted on the support arm 42 so that the angle can be adjusted. Further, the mirror body 46 is directed in a direction in which vibration of the handrail body 31 can be absorbed by forming a bend in the support arm 42. 41 can be oriented in a desired direction.

  When an operator or the like goes up to the lower step 17, he / she grips the curved portion 31 a of the handrail body 31, but the support arm 42 is erected on the cylindrical body 46 constituting the damper member 45, The support arm 42 is easy to grip. Therefore, when trying to climb to the upper swing body 3, the support arm 42 may be grasped and the body may be lifted up so as to put on the weight. The support arm 42 is connected to a sliding body 48 provided in the cylindrical body 46 of the damper member 45, and the sliding body 48 is elastically held by an elastic member 50. Therefore, when a large external force acts on the support arm 42, the spring constant may change, such as permanent deformation, when the elastic member 50 is repeatedly compressed. However, since the support arm 42 is regulated by the groove end portion of the slit groove 47 provided in the cylindrical body 46 and the end portion of the cap 49 and the displacement stroke of the sliding body 48 is regulated, the elastic member 50 is extremely limited. Compressed and not damaged.

  As shown in FIGS. 9 and 10, slits 147 and 147 are formed in the upper and lower portions of the cylindrical body 146 constituting the damper member 145, and the support arm 142 of the mirror 41 is attached to the arm fixing portion of the sliding body 148. It is also possible to provide an extended portion 142a that extends to a lower position of 148a. With this configuration, the support arm 142 to which the mirror 41 is attached is sandwiched between the upper and lower slit grooves 147 and 147 formed in the cylindrical body 146. Therefore, the stability in the direction in which the mirror 41 rotates about the axis of the cylindrical body 146, that is, the tilting direction, is further improved. In addition, the cap 149 may be fixed by screwing the screw 100 into two or more locations of the peripheral body portion instead of being screwed into the cylindrical body 146. Since the configuration other than the above is the same as that of the first embodiment described above, the same reference numerals are given to them.

1 is an external view of a hydraulic excavator as an example of a construction machine to which a handrail is attached. It is an external view which shows the mechanism which enables the raising / lowering to the fuel tank containing the handrail which shows one Embodiment of this invention. FIG. 3 is a left side view of FIG. 2. It is a front view of the handrail which mounted | wore the mirror. It is a front view of the mirror unit connected with the handrail body. It is a disassembled perspective view of a damper member. It is sectional drawing of a damper member. It is explanatory drawing which shows the vibration direction of the handrail main body which is a main vibrating body, and the damper member of the mirror unit as a sub-vibrating body. It is a front view which shows the modification of the mirror unit connected with the handrail main body. FIG. 10 is an exploded perspective view of the damper member of FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Lower traveling body 3 Upper revolving structure 10 Revolving frame 11 Excavation working means 12 Driver's cab 13 Building 15 Fuel tank 16 Hydraulic oil tank 17, 18, 21 Step 30 Handrail 31 Handrail main body 31a Bending part 31b Folding part 31c Vertical portion 32a, 32b End connecting portion 40 Mirror unit 41 Mirror 42, 142 Support arm 43 Clamp member 44 Connecting rod 45, 145 Damper member 46, 146 Cylindrical body 48, 148 Slide body 48a, 148a Arm fixing portion 48b Slide portion 50 Elastic members

Claims (4)

In the handrail, which is provided with both ends of the handrail body made of bent pipes fixed to the upper swing body of the construction machine, and mounted on this handrail body with a mirror connected to the support arm,
Provide a damper member extending from the handrail body,
A handrail for a construction machine, wherein the support arm of the mirror is connected to the damper member. The damper member has a sliding body mounted inside the cylindrical body so as to be slidable in the axial direction of the cylindrical body, the sliding body is sandwiched between elastic members that are pressed from both sides, and the support arm is the sliding body. The construction machine handrail according to claim 1, wherein the construction machine handrail is connected to the construction machine. The cylindrical member constituting the damper member is formed of a member that is directed in a predetermined direction with respect to the handrail body and the elastic member that is applied to both sides of the sliding member has an equal spring constant. 3. The handrail for a construction machine according to claim 2, wherein the moving body is configured to vibrate in a direction to cancel the vibration of the handrail body. The handrail for a construction machine according to claim 3, wherein the cylindrical body is provided with a stopper for restricting a displacement stroke end of the sliding body.

Images