JP2011184919A - Arm for construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect a hose for a bucket cylinder, which is disposed between right and left brackets. <P>SOLUTION: The right and left brackets 27 and 26 are coupled together by means of a brackets coupling plate 34 made of a plate-like body, so as to form a hose storage space 37 surrounded by an inclined back surface 22E of an arm body 22, the right and left brackets 27 and 26, and the brackets coupling plate 34. Thus, the brackets coupling plate 34 inhibits sediment etc. during excavation work from being scattered between the right and left brackets 27 and 26, so that the hose 20A for the bucket cylinder, which is housed in the hose storage space 37, can be protected from the sediment etc. In addition, even when the hose 20A for the bucket cylinder is greatly deformed and displaced following a motion of an arm 21, the brackets coupling plate 34 can inhibit the hose 20A for the bucket cylinder from protruding to the outsides of the right and left brackets 27 and 26. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a construction machine arm suitably used for construction machines such as a hydraulic excavator.

  In general, a hydraulic excavator as 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 an uplifting motion on the front side of the upper revolving body. It is roughly constituted by a working device that can be provided. The working device is usually composed of a boom, an arm, a bucket, a boom cylinder, an arm cylinder, a bucket cylinder, and the like, and performs soil excavation work and the like.

  Here, the arm constituting the work device is usually an arm main body formed in a closed box shape by the upper surface, the lower surface, the left side surface, the right side surface and the rear surface, and a boom connecting boss provided on the base end side of the arm main body. The bucket boss and bucket link boss provided on the front end side of the arm body are separated from each other in front and rear, and the left and right brackets provided on the base end side of the arm body. The bracket has a configuration in which the distal end side of the arm cylinder is pin-coupled to be rotatable and the proximal end side of the bucket cylinder is pin-coupled to be rotatable.

  The bucket cylinder hose connected to the bucket cylinder is usually led from the back side of the arm body to the upper surface side of the arm body through the gap between the left and right brackets, and attached to the left and right brackets. It is the structure connected to a cylinder (for example, refer patent document 1).

JP 2003-155758 A

  However, in this conventional hydraulic excavator, the bucket cylinder hose is disposed in the gap between the left and right brackets provided on the base end side of the arm. For this reason, when the earth and sand at the time of excavation work are scattered between the left and right brackets, the bucket cylinder hose may be damaged by the earth and sand.

  In addition, when the arm rotates on the tip end side of the boom during excavation work, the bucket cylinder hose largely deforms and moves following the rotation of the arm, so that it erodes to the outside from the gap between the left and right brackets. There is a risk that it may be damaged by interference with obstacles such as standing trees and buildings existing around the hydraulic excavator.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a construction machine arm that can protect a bucket cylinder hose disposed between left and right brackets. .

  In order to solve the above-described problems, the present invention provides an arm main body formed in a closed box shape having a triangular longitudinal section by an upper surface, a lower surface, a left side surface, a right side surface, and an inclined rear surface, and a base end side of the arm main body. Boom connecting bosses penetrating left and right at the corners where the lower surface and the inclined rear surface intersect, and left and right at the corners where the upper and lower surfaces intersect on the tip side of the arm body A bucket connecting boss provided through and a bucket link connecting boss provided penetrating left and right in a position spaced forward and rearward from the bucket connecting boss on the front end side of the arm body. A left bracket having an upper end surface, a lower end surface, and a rear end surface, and a base bracket of the arm main body. End A right bracket that is formed in a quadrangular shape extending rearward from the right side surface with the inclined back surface as one side, and a left corner where the upper end surface and the rear end surface of the left bracket intersect with a right bracket having an upper end surface, a lower end surface, and a rear end surface Position, a bucket cylinder coupling boss provided at each right corner position where the upper end surface and the rear end surface of the right bracket intersect, a left corner position where the lower end surface and the rear end surface of the left bracket intersect, and the right bracket This is applied to a construction machine arm constituted by arm cylinder connecting bosses respectively provided at right corner positions where a lower end surface and a rear end surface of each other intersect.

  A feature of the configuration adopted by the invention of claim 1 is that the left bracket and the right bracket are connected between the bucket cylinder connecting boss, the arm cylinder connecting boss, and the inclined back surface of the arm body. An inter-bracket connecting plate made of a plate-like body, and a lower end of the inter-bracket connecting plate located on the lower end surface side of the left and right brackets, and the boom connecting boss. Between the hose inflow opening through which the hose flows and the upper end located on the upper end surface side of the left and right brackets of the inter-bracket connecting plate, and the intersection of the upper surface of the arm body and the inclined rear surface. Hose outflow opening through which the bucket cylinder hose flows out, the inclined rear surface of the arm body, the left and right brackets and brackets. In that a hose accommodating space consisting of a space enclosed by between connecting plate.

  The invention according to claim 2 is that the inter-bracket connecting plate is formed in a mountain shape protruding in a direction away from the inclined back surface of the arm body in order to increase the hose accommodating volume of the hose accommodating space.

  According to a third aspect of the present invention, the inter-bracket connecting plate is provided with a rear opening that opens between rear end surfaces of the left and right brackets in order to discharge earth and sand that has entered the hose housing space. It is in.

  According to a fourth aspect of the present invention, the lower end surfaces of the left and right brackets are formed as extended surfaces extending continuously from the outer peripheral surface of the boom connecting boss, and the upper end surfaces of the left and right brackets are the arms. It is formed as an extended surface continuously extending from the intersection where the upper surface of the main body and the inclined rear surface intersect each other.

  The invention according to claim 5 is that the hose inflow opening side of the inclined back surface of the arm body is formed as a convex curved surface continuous with the outer peripheral surface of the boom connecting boss.

  The invention according to claim 6 is the minimum length between the corner position where the boom connecting boss is provided in the arm body and the corner position where the arm cylinder connecting boss is provided among the left and right brackets. The height dimension is A1, the length dimension in the front and rear direction of the hose inflow opening is A2, and the intersection of the arm body where the upper surface and the inclined rear surface intersect with the bucket cylinder of the left and right brackets. If the minimum length dimension between the corners where the boss is provided is B1, the front and rear length dimensions of the hose outlet opening are B2, and the outer diameter dimension of the bucket cylinder hose is H. The length dimension A2 of the hose inflow opening and the length dimension B2 of the hose outflow opening are set to have a relationship of H <A2 ≦ A1 / 2 and H <B2 ≦ B1 / 2.

  According to the first aspect of the present invention, by connecting the left and right brackets using the inter-bracket connecting plate made of a plate-like body, the inclined back surface of the arm body, the left and right brackets, and the inter-bracket connecting plate Hose accommodating space is formed, and the bucket cylinder hose can be accommodated in the hose accommodating space. For this reason, it is possible to suppress the earth and sand during excavation from being scattered between the left and right brackets by means of the connecting plate between the brackets, and to protect the bucket cylinder hose accommodated in the hose accommodating space from the earth and sand. Can do.

  Even if the bucket cylinder hose is greatly deformed and moved following the movement of the arm during excavation work, the bucket cylinder hose is held in the hose housing space by the connecting plate between the brackets, and this bucket cylinder hose , It can be surely prevented from protruding outside the right bracket, so that the bucket cylinder hose can be protected from surrounding obstacles. Furthermore, since the strength of the entire arm can be increased by connecting the left and right brackets with a bracket-to-bracket connecting plate made of a plate-like body, the reliability of the construction machine can be increased.

  According to invention of Claim 2, the hose accommodation volume of hose accommodation space can be ensured large by forming the connection board between brackets in the mountain shape which protruded in the direction spaced apart from the inclination back surface of an arm main body. As a result, when the bucket cylinder hose accommodated in the hose accommodation space is deformed and moved following the movement of the arm, the curvature of the bucket cylinder hose is suppressed to be small and the degree of freedom of deformation and movement is increased. Therefore, the life of the bucket cylinder hose can be extended.

  According to invention of Claim 3, even if earth and sand etc. at the time of excavation work penetrate | invaded between left and right brackets by providing a rear part opening in the rear end surface of the left and right brackets in the connecting plate between brackets, Since the earth and sand can be discharged to the outside of the hose accommodating space through the rear opening, the bucket cylinder hose accommodated in the hose accommodating space can be protected.

  According to the fourth aspect of the present invention, the lower end surfaces of the left and right brackets are formed as extended surfaces continuous with the outer peripheral surface of the boom connecting boss, and the upper end surfaces of the left and right brackets are connected to the upper surface of the arm body. By forming as an extended surface continuously extending from the intersection where the inclined rear surface intersects the upper surface, the hose accommodating volume of the hose accommodating space can be increased as much as possible.

  According to the invention of claim 5, by forming the hose inflow opening side of the inclined back surface of the arm body as a convex curved surface continuous with the outer peripheral surface of the boom connecting boss, the boundary portion between the boom connecting boss and the inclined back surface. There is no difference in level. For this reason, when the bucket cylinder hose is deformed and moved following the operation of the arm, the bucket cylinder hose can be prevented from being rubbed and damaged at the boundary between the boom connecting boss and the inclined back surface. The life of the bucket cylinder hose can be extended.

  According to the invention of claim 6, since the opening area of the hose inflow opening and the hose outflow opening can be set to an appropriate size, while maintaining the strength of the entire arm including the left and right brackets, It is possible to secure a degree of freedom when the hose is deformed and moved following the movement of the arm.

It is a front view which shows the hydraulic shovel provided with the arm by embodiment of this invention. It is a front view which shows an arm alone. It is the top view which looked at the arm from the arrow III-III direction in FIG. FIG. 4 is an arrow view of the left and right brackets, the hose accommodating space, the hose inflow opening, and the like when viewed from the direction of arrows IV-IV in FIG. 2. It is the longitudinal cross-sectional view which looked at the arm from the arrow VV direction in FIG. It is a perspective view which shows an arm alone. It is a cross-sectional perspective view which looked at the arm from the arrow VII-VII direction in FIG. It is a front view which shows the state which the arm rotated at the time of excavation work. It is a longitudinal cross-sectional view similar to FIG. 5 which shows the modification of an arm.

  Hereinafter, an embodiment of a construction machine arm according to the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the construction machine arm is applied to an arm of a hydraulic excavator.

  In the figure, reference numeral 1 denotes a hydraulic excavator as a typical example of a construction machine. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2 and an upper portion mounted on the lower traveling body 2 so as to be able to turn. The revolving unit 3 and an operation device 10 (described later) provided on the front side of the upper revolving unit 3 so as to move up and down are roughly configured.

  Reference numeral 4 denotes a revolving frame serving as a base of the upper revolving structure 3, and a support bracket 4 </ b> A for supporting a work device 10 described later is provided on the front end side of the revolving frame 4. A counterweight 5 that balances the weight of the working device 10 is disposed on the rear end side of the revolving frame 4.

  6 is an exterior cover provided on the revolving frame 4, and the exterior cover 6 is disposed so as to extend from above the counterweight 5 toward the front side of the revolving frame 4. And the exterior cover 6 is formed as a prone cover which covers mounted equipments (all not shown), such as heat exchangers, such as an engine and a radiator, and a hydraulic pump, from the upper side, for example.

  A driver's seat 7 for an operator to sit on is provided on the upper surface side of the exterior cover 6. In addition, a floor board 8 is provided on the front side of the exterior cover 6 so as to be located above the revolving frame 4, and the operator gets on and off the driver's seat 7 using the floor board 8 as a scaffold. Further, on the front side of the floor board 8, a lever stand 9 having a traveling lever 9A, a working lever 9B, and the like is erected.

  Reference numeral 10 denotes a swing type working device provided on the front side of the upper swing body 3 so as to be able to move up and down. As shown in FIG. The swing post 11 is swingably attached to the swing post 11, the boom 12 is pivotally attached to the swing post 11, and the boom 12 is pivotally attached to the distal end side of the boom 12 using a pin 13. The arm 21 described later, the bucket 15 rotatably attached to the tip end side of the arm 21 using the pin 14, and the pins 16 and 16 between the tip end side of the arm 21 and the bucket 15 are rotated. A bucket link 17 that is movably provided is generally configured.

  Here, a swing cylinder (not shown) that swings the swing post 11 in the left and right directions is provided between the swing frame 4 and the swing post 11, and between the swing post 11 and the boom 12. A boom cylinder 18 is provided for rotating the boom 12 (up and down). An arm cylinder 19 that rotates the arm 21 is provided between the boom 12 and the arm 21, and a bucket cylinder 20 that rotates the bucket 15 is provided between the arm 21 and the bucket link 17. ing.

  The boom cylinder 18 is connected to a boom cylinder hose 18A for supplying and discharging pressure oil to and from the boom cylinder 18, and the arm cylinder 19 is connected to an arm cylinder hose 19A for supplying and discharging pressure oil to and from the arm cylinder 19. Is connected. Further, a bucket cylinder hose 20 </ b> A for supplying and discharging pressure oil to and from the bucket cylinder 20 is connected to the bucket cylinder 20.

  Next, 21 shows an arm according to the present embodiment. The arm 21 constitutes the work device 10 together with the boom 12, the bucket 15, and the like, and is attached to the distal end side of the boom 12 so as to be rotatable. Here, as shown in FIGS. 2 to 7, the arm 21 includes an arm main body 22, a boom connection boss 23, a bucket connection boss 24, a bucket link connection boss 25, left and right brackets 26 and 27, and a bucket cylinder. The connecting bosses 28 and 29, the arm cylinder connecting bosses 31 and 32, the inter-bracket connecting plate 34, and the like are formed integrally using, for example, casting means.

  Reference numeral 22 denotes an arm main body that constitutes a main body portion of the arm 21. The arm main body 22 includes an upper surface 22A and a lower surface 22B that face upward and downward, a left side 22C and a right side 22D that face left and right, It is surrounded by an inclined back surface 22E extending obliquely downward from the rear end side of the upper surface 22A to the rear end side of the lower surface 22B, and the upper surface 22A and the inclined back surface 22E intersect at an intersection 22F. Thereby, the arm main body 22 is formed in the obstruction | occlusion box shape in which the vertical cross section made the substantially triangular shape (refer FIG. 5).

  Reference numeral 23 denotes a boom connecting boss disposed on the base end side of the arm main body 22. The boom connecting boss 23 is arranged at a corner position where the lower surface 22B of the arm main body 22 and the inclined rear surface 22E intersect, and the inner peripheral side is It is a pin insertion hole 23A penetrating in the left and right directions. Then, by inserting the pin 13 through the pin insertion hole 23 </ b> A of the boom connection boss 23 and the distal end side of the boom 12, the arm 21 is attached to the distal end side of the boom 12 so as to be rotatable around the pin 13. It has become.

  In this case, the outer peripheral surface 23B of the boom connecting boss 23 is an arc surface concentric with the pin insertion hole 23A, and the inclined back surface 22E of the arm body 22 is tangent to the outer peripheral surface 23B of the boom connecting boss 23. . Thereby, the hose inflow opening 35 side to be described later of the inclined back surface 22E is formed as a convex curved surface continuous with the outer peripheral surface 23B of the boom connecting boss 23, and the outer peripheral surface of the inclined back surface 22E of the arm body 22 and the boom connecting boss 23 is formed. The boundary with 23B forms a smooth continuous surface with no steps.

  Reference numeral 24 denotes a bucket connecting boss disposed on the distal end side of the arm main body 22. The bucket connecting boss 24 is disposed at a corner position where the upper surface 22A and the lower surface 22B of the arm main body 22 intersect, and the inner peripheral side is on the left, The pin insertion hole 24A penetrates in the right direction. Then, by inserting the pin 14 through the pin insertion hole 24 </ b> A of the bucket connecting boss 24 and the bucket 15, the bucket 15 is attached to the tip side of the arm 21 so as to be rotatable around the pin 14. .

  Reference numeral 25 denotes a bucket link connection boss located near the bucket connection boss 24 and disposed on the front end side of the arm main body 22. The bucket link connection boss 25 is a rear side in the front and rear direction from the bucket connection boss 24 ( Boom connecting boss 23 side) is arranged at a position separated from the inner peripheral side, and the inner peripheral side is a pin insertion hole 25A penetrating left and right. Then, by inserting the pin 16 through the pin insertion hole 25 </ b> A of the bucket link connecting boss 25 and the bucket link 17, one end side of the bucket link 17 is attached to the distal end side of the arm 21 so as to be rotatable around the pin 16. It has a configuration.

  Reference numeral 26 denotes a left bracket disposed on the base end side of the arm main body 22, and the left bracket 26 is paired with a right bracket 27 described later in the left and right directions. The left and right brackets 26 and 27 are attached to the bottom side end of the bucket cylinder 20 and to the rod side end of the arm cylinder 19.

  Here, as shown in FIG. 2 and the like, the left bracket 26 is formed of a plate-like body integrally formed on the left side surface 22C constituting the arm body 22, and extends rearward from the inclined back surface 22E of the arm body 22. Accordingly, the inclined back surface 22E is formed in a quadrangular shape having a rhombus shape or a rectangular shape. The left bracket 26 is connected to the upper end surface 26A continuous with the upper surface 22A of the arm main body 22, the lower end surface 26B continuous with the lower surface 22B of the arm main body 22, and the upper end surface 26A and the lower end surface 26B. And an end face 26C.

  Reference numeral 27 denotes a right bracket disposed on the base end side of the arm body 22 so as to be paired with the left bracket 26 in the left and right directions. The right bracket 27 faces the left bracket 26 with a certain distance. Here, as shown in FIG. 5 and the like, the right bracket 27 is formed of a plate-like body integrally formed on the right side surface 22D constituting the arm body 22, and is extended rearward from the inclined back surface 22E of the arm body 22. Accordingly, the inclined back surface 22E is formed in a quadrangular shape having a rhombus shape or a rectangular shape. The right bracket 27 is connected to the upper end surface 27A continuous with the upper surface 22A of the arm main body 22, the lower end surface 27B continuous with the lower surface 22B of the arm main body 22, and the upper end surface 27A and the lower end surface 27B. And an end face 27C.

  In this case, the lower end surfaces 26B and 27B of the left and right brackets 26 and 27 are tangent to the outer peripheral surface 23B of the boom connecting boss 23 and are formed as extended surfaces extending continuously from the outer peripheral surface 23B. The upper end surfaces 26A, 27A of the right brackets 26, 27 are formed as extended surfaces extending continuously from the intersection 22F where the upper surface 22A of the boom body 22 and the inclined rear surface 22E intersect to the upper surface 22A.

  Reference numerals 28 and 29 denote left and right bucket cylinder connecting bosses provided on the front side of the left and right brackets 26 and 27, respectively. Here, the left bucket cylinder coupling boss 28 is disposed at the left corner where the upper end surface 26A and the rear end surface 26C of the left bracket 26 intersect, and the inner peripheral side thereof is a pin insertion hole 28A (FIG. 2). reference). Further, the right bucket cylinder connecting boss 29 is arranged at the right corner where the upper end surface 27A and the rear end surface 27C of the right bracket 27 intersect, and the inner peripheral side thereof is a pin insertion hole 29A (see FIG. 5). .

  Then, the bottom side end portion of the bucket cylinder 20 is sandwiched between the left and right bucket cylinder connection bosses 28 and 29, and the bottom side end portion of the bucket cylinder 20 and the left and right bucket cylinder connection bosses 28 and 29 are connected. By inserting the pin 30 through the pin insertion holes 28 </ b> A and 29 </ b> A, the bottom end of the bucket cylinder 20 is attached to the left and right brackets 26 and 27 of the arm 21 via the pin 30. (See FIG. 1).

  Reference numerals 31 and 32 denote left and right arm cylinder connecting bosses provided on the rear side of the left and right brackets 26 and 27, respectively. Here, the left arm cylinder connecting boss 31 is disposed at the left corner where the lower end surface 26B and the rear end surface 26C of the left bracket 26 intersect, and the inner peripheral side thereof is a pin insertion hole 31A (FIG. 2). reference). The right arm cylinder coupling boss 32 is disposed at the right corner where the lower end surface 27B and the rear end surface 27C of the right bracket 27 intersect, and the inner peripheral side thereof is a pin insertion hole 32A (see FIG. 5). .

  Then, the rod side end of the arm cylinder 19 is sandwiched between the left and right arm cylinder connecting bosses 31 and 32, and the rod side end of the arm cylinder 19 and the left and right arm cylinder connecting bosses 31 and 32 are connected. By inserting the pin 33 into the pin insertion holes 31 </ b> A and 32 </ b> A, the rod side end of the arm cylinder 19 is attached to the left and right brackets 26 and 27 of the arm 21 via the pin 33. (See FIG. 1).

  An inter-bracket connecting plate 34 is provided between the left and right brackets 26 and 27 and connected between the brackets 27 and 27. The inter-bracket connecting plate 34 is an inclined back surface 22E of the arm body 22 as shown in FIGS. The left and right bucket cylinder connecting bosses 28 and 29 and the left and right arm cylinder connecting bosses 31 and 32 are separated from each other and are integrated with the left and right brackets 26 and 27. Is formed. Here, the inter-bracket connecting plate 34 extends from the upper end 34A that intersects the upper end surfaces 26A and 27A of the brackets 26 and 27 to the lower end 34B that intersects the lower end surfaces 26B and 27B of the brackets 26 and 27. Are facing each other. Further, an intermediate portion in the length direction of the inter-bracket connecting plate 34 protrudes in a direction away from the inclined back surface 22E of the arm body 22.

  As a result, the inter-bracket connecting plate 34 is a convex curved surface that passes between the left and right bucket cylinder connecting bosses 28 and 29, the left and right arm cylinder connecting bosses 31 and 32, and the inclined back surface 22E of the arm body 22. It is formed in a mountain shape with That is, the inter-bracket connecting plate 34 is formed in a mountain shape that passes through the inside of the left and right bucket cylinder connecting bosses 28 and 29 and the left and right arm cylinder connecting bosses 31 and 32. The bracket-to-bracket connecting plate 34 reinforces the left and right brackets 26 and 27 by connecting the left and right brackets 26 and 27 facing each other in the left and right directions with a space therebetween, and the left and right brackets. A hose housing space 37 to be described later is formed between the brackets 26 and 27 and the inclined back surface 22E of the arm body 22.

  35 is a hose inflow opening formed between the lower end 34B of the inter-bracket connection plate 34 and the boom connection boss 23, and the hose inflow opening 35 is a rectangular hole that opens into a hose accommodating space 37 to be described later. A bucket cylinder hose 20 </ b> A connected to the bucket cylinder 20 passes through the hose accommodating space 37.

  Reference numeral 36 denotes a hose outflow opening formed between an upper end 34A of the inter-bracket connecting plate 34 and an intersection 22F where the upper surface 22A of the arm body 22 and the inclined rear surface 22E intersect. The hose outflow opening 36 is a hose accommodating space. The bucket cylinder hose 20 </ b> A passes through the hose accommodating space 37.

  Here, as shown in FIG. 5, the corner position of the arm body 22 where the boom connecting boss 23 is provided, and the corner of the left and right brackets 26 and 27 where the arm cylinder connecting bosses 31 and 32 are provided. Assuming that the minimum length between the corner positions is A1, the length in the front and rear direction of the hose inflow opening 35 is A2, and the outer diameter of the bucket cylinder hose 20A is H, the hose inflow opening 35 The length dimension A2 is set as shown in Equation 1 below.

  Further, the minimum length between the intersection 22F where the upper surface 22A and the inclined rear surface 22E of the arm main body 22 intersect with the corner corner position of the left and right brackets 26 and 27 where the bucket cylinder coupling bosses 28 and 29 are provided. The length dimension B2 of the hose outflow opening 36 is expressed as follows, where B1 is the length dimension, B2 is the length in the front and rear direction of the hose outflow opening 36, and H is the outer diameter dimension of the bucket cylinder hose 20A. 2 is set.

  On the other hand, as shown in FIGS. 3 and 4, the left and right width dimension C of the hose inflow opening 35 and the left and right width dimension D of the hose outflow opening 36 are the left and right brackets 26, 27 is set to be approximately equal to the interval between the inner side surfaces.

  Thereby, the opening area of the hose inflow opening 35 and the hose outflow opening 36 can be set to an appropriate size, and the work apparatus 10 can be maintained while maintaining the strength of the entire arm 21 including the left and right brackets 26 and 27. Following the operation of the arm 21 during the excavation work used, the bucket cylinder hose 20 </ b> A can be allowed to smoothly deform and move within a hose accommodating space 37 described later.

  Reference numeral 37 denotes a hose accommodating space surrounded by the inclined back surface 22E of the arm body 22, left and right brackets 26 and 27, and an inter-bracket connecting plate 34. The hose accommodating space 37 accommodates the bucket cylinder hose 20A. It is.

  In this case, as described above, the lower end surfaces 26B, 27B of the left and right brackets 26, 27 are tangent to the outer peripheral surface 23B of the boom connecting boss 23 and extend continuously from the outer peripheral surface 23B. The upper end surfaces 26A, 27A of the left and right brackets 26, 27 are formed as extended surfaces extending continuously from the intersection point 22F where the upper surface 22A of the boom body 22 and the inclined rear surface 22E intersect to the upper surface 22A. . Further, the bracket connecting plate 34 is formed in a mountain shape in which an intermediate portion in the length direction protrudes in a direction away from the inclined back surface 22E of the arm body 22 (see FIG. 5).

  For this reason, the hose accommodation volume of the hose accommodation space 37 surrounded by the inclined back surface 22E of the arm body 22, the left and right brackets 26 and 27, and the inter-bracket connection plate 34 can be ensured as large as possible. As a result, as shown in FIG. 8, when the bucket cylinder hose 20 </ b> A accommodated in the hose accommodating space 37 is deformed and moves following the operation of the arm 21 during excavation work using the working device 10. The curvature of the bucket cylinder hose 20A can be kept small.

  Further, by accommodating the bucket cylinder hose 20A in the hose accommodating space 37, it is possible to suppress the earth and sand during excavation work from being scattered between the left and right brackets 26 and 27 by the inter-bracket connecting plate 34. The bucket cylinder hose 20A housed in the hose housing space 37 can be protected from earth and sand.

  Reference numeral 38 denotes a rear opening provided in the connecting plate 34 between brackets, and the rear opening 38 discharges earth and sand that has entered the hose accommodating space 37 to the outside. Here, the rear opening 38 is a rectangular hole formed at the top of the inter-bracket connecting plate 34 having a mountain shape, and is opened between the rear end surfaces 26C and 27C of the left and right brackets 26 and 27.

  For example, as shown in FIG. 8, when the boom 12 is rotated downward with respect to the swing post 11 with the distal end side of the arm 21 approaching the boom 12, the arm 21 enters the hose accommodating space 37. The earth and sand can be discharged to the outside of the hose accommodating space 37 through the rear opening 38.

  As shown in FIG. 8, when the boom 12 is rotated upward with respect to the swing post 11 with the distal end side of the arm 21 approaching the boom 12, the earth and sand in the hose accommodating space 37 flows out of the hose. When the boom 12 is rotated upward with respect to the swing post 11 with the distal end side of the arm 21 being separated from the boom 12, the earth and sand in the hose accommodating space 37 can be removed. The hose inflow opening 35 can be discharged to the outside.

  The arm 21 according to the present embodiment has the above-described configuration. The hydraulic excavator 1 provided with the arm 21 self-travels to the work site by the lower traveling body 2 and then the upper swing body on the lower traveling body 2. Excavation work of earth and sand is performed by swinging up and down the working device 10 while turning 3.

  Here, when excavation work is performed using the working device 10, for example, as illustrated in FIG. 8, the bucket cylinder hose 20 </ b> A connected to the bucket cylinder 20 is housed in the hose housing space 37 of the arm 21. Thus, the deformation and movement are repeated following the operation of the arm 21.

  In this case, the arm 21 according to the present embodiment connects the left bracket 26 and the right bracket 27 by using an inter-bracket connecting plate 34 made of a plate-like body, whereby an inclined back surface 22E of the arm body 22 is obtained. A hose accommodating space 37 surrounded by the left and right brackets 26 and 27 and the inter-bracket connecting plate 34 is formed, and the bucket cylinder hose 20 </ b> A is accommodated in the hose accommodating space 37.

  For this reason, it is possible for the earth and sand during excavation work to be prevented from scattering between the left and right brackets 26 and 27 by the inter-bracket connecting plate 34, and the bucket cylinder hose 20A accommodated in the hose accommodating space 37 can be removed. It can be protected from earth and sand.

  Further, even if the bucket cylinder hose 20 </ b> A greatly deforms and moves following the operation of the arm 21 during excavation work, the bucket cylinder hose 20 </ b> A is held in the hose accommodating space 37 by the inter-bracket connecting plate 34. Can do. As a result, the bucket cylinder hose 20A can be reliably prevented from protruding outside the left and right brackets 26 and 27, so that the bucket cylinder hose 20A can be protected from surrounding obstacles.

  In addition, since the inter-bracket connecting plate 34 is formed in a mountain shape in which the intermediate portion in the length direction protrudes in a direction away from the inclined rear surface 22E of the arm body 22, the hose accommodating space 37 can have a hose accommodating volume as much as possible. Can be secured large. As a result, as shown in FIG. 8, when the bucket cylinder hose 20 </ b> A accommodated in the hose accommodating space 37 is deformed and moved following the operation of the arm 21 during excavation work using the working device 10. Since the curvature of the bucket cylinder hose 20A can be kept small and the degree of freedom of deformation and movement can be increased, the life of the bucket cylinder hose 20A can be extended.

  Further, by connecting the left bracket 26 and the right bracket 27 by a bracket-to-bracket connecting plate 34 made of a plate-like body, the strength of the entire arm 21 including the left and right brackets 26 and 27 can be increased. The reliability of the excavator 1 can be increased.

  Further, since the hose inflow opening 35 side of the inclined back surface 22E of the arm body 22 is formed as a convex curved surface continuous with the outer peripheral surface 23B of the boom connection boss 23, the inclined back surface 22E of the arm body 22 and the boom connection boss 23 The boundary portion with the outer peripheral surface 23B can be a smooth continuous surface having no step. As a result, when the bucket cylinder hose 20A is deformed and moved following the movement of the arm 21, the bucket cylinder hose 20A is rubbed and damaged at the boundary between the inclined back surface 22E of the arm body 22 and the boom connection boss 23. Can be prevented, and the life of the bucket cylinder hose 20A can be extended.

  Further, the length dimension A2 of the hose inflow opening 35 that opens into the hose accommodating space 37 is set as shown in the above formula 1, and the length dimension B2 of the hose outflow opening 36 is set as shown in the above formula 2, so that the hose The opening area of the inflow opening 35 and the hose outflow opening 36 can be set to an appropriate size. Thereby, while maintaining the strength of the entire arm 21 including the left and right brackets 26 and 27, it is possible to secure a degree of freedom when the bucket cylinder hose 20 </ b> A is deformed and moved following the operation of the arm 21. .

  Further, even when soil or the like enters the hose accommodation space 37 during excavation work using the work device 10, for example, the arm 21 takes the work posture shown in FIG. The hose outlet opening 36, the hose inlet opening 35, and the rear opening 38 of the inter-bracket connecting plate 34 can be discharged to the outside, and the life of the bucket cylinder hose 20A accommodated in the hose accommodating space 37 can be extended.

  In the above-described embodiment, the bracket connecting plates 34 for connecting the left and right brackets 26 and 27 are connected to the left and right bucket cylinder connecting bosses 28 and 29, the left and right arm cylinder connecting bosses 31, The case where it forms in the mountain shape with the convex curve surface which passes between between 32 and the inclined back surface 22E of the arm main body 22 is illustrated. However, the present invention is not limited to this, and the left and right bucket cylinder coupling bosses 28 and 29, the left and right arm cylinder coupling bosses 31 and 32, and the inclined rear surface 22E, for example, as in the modification shown in FIG. It is also possible to use a mountain-shaped bracket-to-bracket connecting plate 34 ′ having an inclined plane that passes between them.

  In the above-described embodiment, the arm 21 is described as being integrally formed using casting means. However, the present invention is not limited to this, and for example, means such as welding the left and right brackets to the arm body. It is good also as a structure joined using.

1 Excavator (construction machine)
DESCRIPTION OF SYMBOLS 10 Work apparatus 20 Bucket cylinder 20A Bucket cylinder hose 21 Arm 22 Arm main body 22A Upper surface 22B Lower surface 22C Left side surface 22D Right side surface 22E Inclined back surface 22F Intersection 23 Boom connection boss 24 Bucket connection boss 25 Bucket link connection boss 26 Left bracket 26A, 27A Upper end face 26B, 27B Lower end face 26C, 27C Rear end face 27 Right bracket 28, 29 Bucket cylinder connection boss 31, 32 Arm cylinder connection boss 34, 34 'Inter-bracket connection plate 34A Upper end 34B Lower end 35 Hose inlet opening 36 Hose Outflow opening 37 Hose housing space 38 Rear opening

Claims (6)

An arm main body formed in a closed box shape with a vertical cross section formed by an upper surface, a lower surface, a left side surface, a right side surface and an inclined back surface;
A boom connecting boss provided penetrating in the left and right directions at the corner position where the lower surface and the inclined rear surface intersect on the base end side of the arm body;
A bucket connecting boss provided penetrating in the left and right directions at a corner position where the upper surface and the lower surface intersect at the tip side of the arm body;
A bucket link coupling boss provided penetrating left and right in a position spaced forward and rearward from the bucket coupling boss on the tip side of the arm body;
A left bracket having an upper end surface, a lower end surface, and a rear end surface, which is formed in a quadrangular shape extending rearward from the left side surface as a side from the left side surface on the base end side of the arm body,
A right bracket having an upper end surface, a lower end surface, and a rear end surface, which is formed in a quadrangular shape by extending rearward from the right side surface as a side from the right side surface on the base end side of the arm body,
Bucket cylinder coupling bosses provided at the left corner position where the upper end surface and the rear end surface of the left bracket intersect, and at the right corner position where the upper end surface and the rear end surface of the right bracket intersect,
For a construction machine comprising a left corner position where the lower end surface and the rear end surface of the left bracket intersect, and an arm cylinder connecting boss provided at a right corner position where the lower end surface and the rear end surface of the right bracket intersect. In the arm
An inter-bracket connecting plate formed of a plate-like body provided by connecting the left bracket and the right bracket between the bucket cylinder connecting boss, the arm cylinder connecting boss and the inclined back surface of the arm body;
A hose inlet opening formed between the lower end of the left and right brackets on the lower end surface side of the bracket connecting plate and the boom connecting boss, and through which the bucket cylinder hose flows,
The bucket cylinder hose is formed between the upper end of the inter-bracket connecting plate located on the upper end surface side of the left and right brackets and the intersection where the upper surface of the arm body and the inclined rear surface intersect. A hose outlet opening that passes through
A construction machine arm comprising an inclined rear surface of the arm body, left and right brackets, and a hose housing space formed by a space surrounded by a connecting plate between brackets.   2. The construction machine according to claim 1, wherein the inter-bracket connecting plate is formed in a mountain shape protruding in a direction away from the inclined rear surface of the arm body in order to increase a hose accommodating volume of the hose accommodating space. arm.   3. The structure according to claim 1, wherein the inter-bracket connecting plate is provided with a rear opening that opens between rear end surfaces of the left and right brackets in order to discharge earth and sand that has entered the hose housing space. Arm for construction machinery.   Lower end surfaces of the left and right brackets are formed as extended surfaces extending continuously to an outer peripheral surface of the boom connecting boss, and upper end surfaces of the left and right brackets are an upper surface and an inclined rear surface of the arm body. The construction machine arm according to claim 1, 2, or 3, wherein the construction machine arm is formed as an extended surface continuously extending from the intersection where the two intersect each other to the upper surface.   5. The construction machine arm according to claim 1, 2, 3, or 4, wherein the hose inflow opening side of the inclined back surface of the arm body is formed as a convex curved surface continuous with an outer peripheral surface of the boom connection boss. A1 is a minimum length dimension between the corner position of the arm body where the boom connection boss is provided and the corner position of the left and right brackets where the arm cylinder connection boss is provided;
A2 is the length dimension in the front and rear direction of the hose inlet opening,
B1 is the minimum length dimension between the intersection point of the upper surface of the arm body and the inclined back surface and the corner position of the left and right brackets where the bucket cylinder connection boss is provided,
The length dimension in the front and rear direction of the hose outlet opening is B2,
When the outer diameter of the bucket cylinder hose is H,
The length dimension A2 of the hose inflow opening and the length dimension B2 of the hose outflow opening are:

The construction machine arm according to claim 1, wherein the construction machine arm is set in the relationship of

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