JP4188783B2 - Construction machine swivel frame - Google Patents

Description

  The present invention relates to a swing frame of a construction machine suitably used for an upper swing body such as a hydraulic excavator, and more particularly, a construction in which a swing post type working device is swung left and right using a swing cylinder. The present invention relates to a swing frame of a machine.

  Generally, a construction machine such as a hydraulic excavator includes a lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a working device that is provided on the front side of the upper revolving body and performs excavation work of earth and sand. It is comprised by.

  In addition, a small hydraulic excavator or the like called a so-called small rear swivel type is configured such that the boom of the working device is connected to the swing frame of the upper swing body so as to be swingable left and right using a swing post or the like. A swing post type working device is employed (for example, see Patent Documents 1 and 2).

JP 2000-27235 A JP 2001-59237 A

  A swivel frame according to this type of prior art includes a bottom plate that is turnably mounted on a lower traveling body, a left and right vertical plate that is erected upward from the bottom plate and extends in front and rear of the bottom plate, It is composed of a right vertical plate and a swing bracket that is provided on the front end side of the bottom plate and supports a swing post type working device so as to be swingable leftward and rightward.

  A cylinder mounting portion serving as a bracket is provided on the bottom plate of the revolving frame and is located outside the left and right vertical plates. The cylinder mounting portion swings the working device in the left and right directions. The swing cylinder for making it rotate is attached via a connection pin so that rotation is possible.

  In this case, a pin hole for inserting the connecting pin is provided on the bottom side of the swing cylinder, and a similar pin hole is formed in the cylinder mounting portion of the turning frame. The connecting pins are respectively inserted into pin holes between the bottom side of the swing cylinder and the cylinder mounting portion from above the swing frame, and connect the swing cylinder to the swing frame so as to be rotatable.

  By the way, in the above-mentioned prior art, since the connecting pin that rotatably connects the bottom side of the swing cylinder to the cylinder mounting portion provided on the bottom plate of the swing frame is configured to be inserted and removed from above the swing frame, The following problems have occurred.

  In other words, a hydraulic oil tank, a fuel tank, a driver's seat floor plate, or the like is disposed above the swing cylinder in a revolving frame such as a hydraulic excavator. When performing maintenance, inspection, etc. of the swing cylinder, it is necessary to insert and remove the connecting pin from the pin hole between the bottom side of the swing cylinder and the cylinder mounting portion.

  However, for this purpose, unless the hydraulic oil tank, fuel tank or driver's seat floor plate, etc., disposed above the swing cylinder is removed in advance from the swivel frame, the connecting pin cannot be removed from the swivel frame. Can not. And since the work of removing the hydraulic oil tank etc. from the upper part of the swing cylinder is a troublesome work, the extra work and time are spent on the maintenance and inspection of the swing cylinder, and the workability at the time of maintenance is very poor. There is.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to enable the connecting pin to be inserted / removed from the lower side of the swing frame and to efficiently perform maintenance, inspection, etc. of the swing cylinder. Another object of the present invention is to provide a swing frame for a construction machine capable of greatly improving workability during maintenance.

  In order to solve the above-described problems, the present invention includes a bottom plate provided on a lower traveling body via a swivel ring, and left and right verticals standing upward from the bottom plate and extending in the front and rear directions of the bottom plate. A plate, a swing bracket provided on the front end side of the left and right vertical plates and the bottom plate and supporting a swing post type working device so as to be swingable in the left and right directions; and the working device in the left and right directions A swing frame for a construction machine comprising a cylinder mounting portion provided on the bottom plate and positioned on the outside of the left and right vertical plates for pivotally mounting a swing cylinder for swinging via a connecting pin. Applies to

A feature of the configuration adopted by the invention of claim 1 is that the bottom plate is provided with a detaching hole for inserting and removing the connecting pin from the swing cylinder to the bottom of the bottom plate, located below the cylinder mounting portion. The connecting pin has a pin shaft portion that is inserted into a pin hole provided in each of the bottom side of the swing cylinder and the cylinder mounting portion, and projects in a radial direction from one end portion of the pin shaft portion. And the attachment / detachment hole of the bottom plate has a configuration in which the flange portion of the connecting pin is disposed inside .

This ensures that the flange portion of the connecting pin can be accommodated in the bottom plate of the desorption in the hole, the flange portion of the connection pin from the lower surface of the rotating frame can be prevented from protruding downward.

According to the invention of claim 2 , the flange portion of the connecting pin is configured to be fixed from below using a fixing member on the lower surface side of the cylinder mounting portion in a state where it is disposed in the attachment / detachment hole of the bottom plate. In this case, the connecting pin can be fixed to the lower surface side of the cylinder mounting portion from below with the fixing member in a state where the flange portion of the connecting pin is disposed in the mounting hole of the bottom plate. It can be held in a stopped state.

According to the invention of claim 3 , the flange portion of the connecting pin has a non-circular outer shape, and the attachment / detachment hole of the bottom plate is formed in a hole shape that can be accommodated in a rotation-stopped state. . Thereby, the attachment / detachment hole of the bottom plate can accommodate the flange portion of the connecting pin in a stopped state.

On the other hand, according to the invention of claim 4, the heat exchanger bracket on which the heat exchanger for cooling the prime mover of the construction machine is mounted is provided on the bottom plate, and the heat exchanger bracket is connected to the cylinder mounting portion. The bottom side of the swing cylinder is sandwiched from above and below, and supported by a connecting pin so as to be rotatable. As a result, the heat exchanger bracket can be supported so as to sandwich the bottom side of the swing cylinder from above and below with the cylinder mounting portion, and the bottom side of the swing cylinder can be prevented from being accidentally detached from the connecting pin.

According to a fifth aspect of the present invention, an under cover extending to the position of the attachment / detachment hole is provided on the lower surface of the bottom plate, and the under cover is configured to prevent the connection pin from falling downward from the attachment / detachment hole. The part is at least partially covered from below. In this case, it is possible to prevent the connecting pin from accidentally falling downward from the attachment / detachment hole of the bottom plate by at least partially covering the flange portion of the connecting pin with the under cover.

As described above, according to the first aspect of the present invention, in the swing frame of the construction machine including the cylinder mounting portion for the swing cylinder that swings the swing post type working device in the left and right directions, the cylinder mounting The bottom plate of the swivel frame is provided with a detaching hole for inserting and removing the connecting pin downward from the swing cylinder at a position on the lower side of the swinging portion, and the connecting pin is attached to the bottom side of the swing cylinder and the cylinder mounting A pin shaft portion inserted into a pin hole provided in each of the portions, and a flange portion protruding radially from one end portion of the pin shaft portion, and the desorption hole of the bottom plate is connected to the inside since the construction of arranging the flange portion of the pin, the swing cylinder maintenance, when performing inspection or the like, a connecting pin and a cylinder attachment portion and the swing cylinder of the rotating frame, the bottom plate Chakuana can connect or disconnect the downward pivoting frame using, can be removed easily swing cylinder from the cylinder attachment portion.

  As a result, when performing maintenance, inspection, etc. of the swing cylinder, for example, the work of removing the hydraulic oil tank etc. provided on the bottom plate of the swing frame can be eliminated, and the maintenance, inspection, etc. of the swing cylinder can be performed efficiently. In addition, the workability during maintenance can be greatly improved.

In addition , the connecting pin has a pin shaft portion and a flange portion, and the desorption hole of the bottom plate has a configuration in which the flange portion of the connection pin is arranged inside, so that the flange portion of the connection pin is accommodated in the desorption hole of the bottom plate. It is possible to suppress the protruding portion of the connecting pin from protruding downward from the lower surface of the swivel frame, and to reduce the possibility that the connecting portion of the connecting pin may collide with an obstacle or the like to be damaged or broken. it can.

Further, according to the invention described in claim 2 , the flange portion of the connecting pin is configured to be fixed from below using a fixing member on the lower surface side of the cylinder mounting portion in a state of being arranged in the attachment / detachment hole of the bottom plate. With the flange of the pin placed in the mounting hole of the bottom plate, it can be fixed from below by a fixing member on the lower surface side of the cylinder mounting part. Can do.

According to a third aspect of the present invention, the flange portion of the connecting pin has a non-circular outer shape, and the detachment hole of the bottom plate is formed in a hole shape that can be accommodated in a non-rotating state. Therefore, the flange portion of the connecting pin can be accommodated in the demounting hole of the bottom plate in a non-rotating state, and the connecting pin can be reliably prevented from rotating.

On the other hand, according to the invention described in claim 4 , the heat exchanger bracket on which the heat exchanger for cooling the prime mover of the construction machine is mounted is provided on the bottom plate, and the bracket for the heat exchanger is provided with the cylinder mounting portion. The bottom side of the swing cylinder is supported between the heat exchanger bracket and the cylinder mounting part by sandwiching the bottom side of the swing cylinder from above and from below, and using a connecting pin so as to be rotatable. It can be supported so as to be sandwiched from above and below, so that the bottom side of the swing cylinder can be prevented from being accidentally detached from the connecting pin, and a part of the external force acting on the swing cylinder can be received by the heat exchanger bracket.

Furthermore, according to the invention described in claim 5 , an under cover extending to the position of the attachment / detachment hole is provided on the lower surface of the bottom plate, and the under cover is configured to prevent the connection pin from coming out of the attachment / detachment hole. The cover pin is at least partially covered from the lower side, so that the connection pin accidentally falls out of the bottom plate attaching / detaching hole by covering the hook part of the connection pin with the under cover at least partially from the lower side. Can be prevented. Further, the under cover can protect the hook portion of the connecting pin, and the hook portion of the connecting pin can be prevented from being damaged or broken by colliding with an obstacle or the like on the lower surface side of the turning frame.

  Hereinafter, a case where the swing frame of the construction machine according to the embodiment of the present invention is applied to a rear small swing type hydraulic excavator will be described as an example and described in detail with reference to the accompanying drawings.

  Here, FIG. 1 to FIG. 10 show a first embodiment of the present invention. In the figure, 1 is a hydraulic excavator as a construction machine. The hydraulic excavator 1 includes a lower traveling body 2, and an upper revolving body 4 mounted on the lower traveling body 2 so as to be capable of swiveling using a swirling wheel 3. It is comprised by the below-mentioned working device 8 grade | etc.,.

  Further, the upper swing body 4 has a swing frame 11 which will be described later. On the swing frame 11, a cab 5, an exterior cover 6, a counterweight 7, and the like are provided as shown in FIGS. And the cab 5 comprises the operation driving | operation part which an operator gets on and off, and has defined the cab in the inside. The exterior cover 6 together with the counterweight 7 defines a machine room in which an engine 51, a radiator 52, a hydraulic pump (not shown), etc., which will be described later, are accommodated.

  8 is a swing post type working device provided on the front side of the upper swing body 4 so as to be able to move up and down. The working device 8 includes, for example, a swing post 8A, a boom 8B, an arm 8C, a bucket 8D, and the like. . The swing post 8A of the work device 8 is attached to the swing bracket 18 of the revolving frame 11 described later using a connecting pin 9 shown in FIG.

  As a result, the swing post type working device 8 is swung left and right around the connecting pin 9 shown in FIG. 2, and the boom 8B and the arm 8C are lifted up and down, leading to the tip side. The bucket 8D performs excavation work (including side trenches) such as earth and sand.

  On the other hand, on the front side of the lower traveling body 2, as shown in FIG. The earth removal board 10 is used when earth removal work such as earth and sand, leveling work, and the like are performed. The earth removal board 10 is also used as an outrigger for stabilizing the vehicle posture.

  Reference numeral 11 denotes a revolving frame constituting a main frame of the upper revolving structure 4, and the revolving frame 11 includes a center frame 12 (to be described later) and left and right side frames 30 and 31 as shown in FIGS. It is configured.

  Reference numeral 12 denotes a center frame that constitutes the central portion of the revolving frame 11, and the center frame 12 is formed of a flat plate material as shown in FIGS. The front vertical plates 16 and 17, the swing bracket 18, the closing plate 25, the horizontal plate 26, the rear vertical plates 27 and 28, the weight attaching portion 29, and the like.

  The bottom plate 13 of the swivel frame 11 is formed with a large number of bolt holes 13A, 13A,... Spaced apart from each other in the circumferential direction so as to be concentric with the swivel center O as shown in FIGS. Bolts (not shown) and the like for attaching the swivel wheels 3 to the lower traveling body 2 shown in FIG. 1 are screwed into these bolt holes 13A.

  As a result, the bottom plate 13 of the turning frame 11 is attached to the lower traveling body 2 so as to be turnable via the turning wheel 3 at the center in the length direction (front and rear directions). Turned to the right. Further, the front end portion 13B of the bottom plate 13 is joined to the lower plate portion 20 of the swing bracket 18 described later using welding means as shown in FIG.

  14 and 15 are left and right vertical plates standing on the upper surface side of the bottom plate 13 and extending in the front and rear directions. The vertical plates 14 and 15 are interposed between a swing bracket 18 and a horizontal plate 26 described later. It is composed of left and right front vertical plates 16 and 17 erected on the bottom plate 13 and left and right rear vertical plates 27 and 28 described later.

  Here, the left and right front vertical plates 16 and 17 are arranged so as to extend in a substantially “C” shape spaced apart from the left and right sides with respect to the turning center O as shown in FIGS. 3 to 5. The front end side is joined to a swing bracket 18 described later from both the left and right sides.

  That is, the left and right front vertical plates 16 and 17 are erected upward from the upper surface of the bottom plate 13 as shown in FIGS. 3 to 5 in order to increase the bending rigidity of the revolving frame 11, and the swing bracket 18 described later. And the horizontal plate 26 form a straight line and extend obliquely to each other. The left and right front vertical plates 16 and 17 have a height dimension that protrudes upward from an upper plate portion 21 of a swing bracket 18 described later, and these protruding portions are on the left and right sides of the upper plate portion 21. The fillet is welded as described later.

  Reference numeral 18 denotes a swing bracket provided on the front end side of the bottom plate 13 and the front vertical plates 16 and 17, and the swing bracket 18 is integrally formed as a cast part using a material such as cast steel, for example. As shown in FIG. 6, the boss portion 19 is formed by an integral body including a cylindrical boss portion 19 that extends upward and downward, and a lower plate portion 20 and an upper plate portion 21 described later.

  Further, as shown in FIGS. 3, 5, and 6, the front vertical plates 16 and 17 are joined to the boss portion 19 of the swing bracket 18 in a state where the front ends of the front vertical plates 16 and 17 abut against the outer peripheral side. Further, the boss portion 19 of the swing bracket 18 has a pin hole 19A extending through in the vertical direction, and the connecting pin 9 illustrated in FIG. 2 is rotatably inserted into the pin hole 19A. . As a result, the swing post 8A of the work device 8 is connected to the swing bracket 18 so as to be swingable left and right.

  Reference numeral 20 denotes a lower plate portion that forms a part of the swing bracket 18, and the lower plate portion 20 extends obliquely downward from the outer periphery of the lower end of the boss portion 19 as shown in FIGS. 3, 5, and 6. The left and right sides have a substantially “C” -shaped divergent shape. The front lower end sides of the front vertical plates 16 and 17 are joined to the left and right sides of the lower plate portion 20 in an abutting state.

  Reference numeral 21 denotes an upper plate portion that forms a part of the swing bracket 18. The upper plate portion 21 is opposed to the lower plate portion 20 at the upper and lower sides, and the front side thereof is the upper outer periphery of the boss portion 19 as shown in FIG. The flat surface portion 21A is integrally formed on the side. In addition, the rear side of the upper plate portion 21 is an inclined surface portion 21B that extends obliquely downward and obliquely backward with respect to the flat surface portion 21A.

  Then, the upper plate portion 21 composed of the flat surface portion 21A and the inclined surface portion 21B is formed so as to form a divergent shape having a substantially “C” shape on both the left and right sides thereof in the same manner as the lower plate portion 20. . Further, a later-described receiving seat 22 that protrudes upward is integrally formed on the inclined surface portion 21 </ b> B of the upper plate portion 21.

  Further, the flat surface portion 21 </ b> A of the upper plate portion 21 is disposed at a height position lower than the upper ends of the front vertical plates 16 and 17 by a predetermined dimension. Then, the front vertical plates 16 and 17 are joined to the flat surface portion 21A and the inclined surface portion 21B of the upper plate portion 21 on the left and right sides thereof using means such as fillet welding.

  Reference numeral 22 denotes a seat provided on the upper plate portion 21 of the swing bracket 18, and the seat 22 protrudes upward from the inclined surface portion 21B of the upper plate portion 21 as shown in FIG. And the receiving seat 22 supports the floor (floor board) side of the cab 5 where an operator gets on and off from the lower side via the cab support plate 38 etc. which are mentioned later.

  Reference numerals 23 and 24 denote left and right fitting protrusions integrally formed on the left and right sides of the lower plate portion 20, respectively. The fitting protrusions 23 and 24 protrude from the lower plate portion 20 in the left and right directions. Side frames 30 and 31, which will be described later, are fitted and fixed in the left and right directions. Thus, the front end sides of the side frames 30 and 31 are connected to the swing bracket 18 via the left and right fitting convex portions 23 and 24, respectively.

  Reference numeral 25 denotes a closing plate provided between the upper plate portion 21 and the bottom plate 13 of the swing bracket 18. The closing plate 25 is formed by using a plate material such as a steel plate, and as shown in FIGS. Corresponding to the plate portion 21, a substantially “C” -shaped divergent shape is formed. The closing plate 25 is located between the left and right front vertical plates 16 and 17 and is disposed between the inclined surface portion 21 </ b> B of the upper plate portion 21 and the bottom plate 13.

  Here, the front end side of the closing plate 25 is joined to the inclined surface portion 21 </ b> B of the upper plate portion 21 by means such as fillet welding, and the rear end side is joined to the upper surface of the bottom plate 13. Further, the left and right sides of the closing plate 25 are joined to the front vertical plates 16 and 17 by means such as fillet welding.

  And the obstruction board 25 inclines in the front and back direction between the left and right front vertical plates 16 and 17 along the inclined surface portion 21B of the upper plate portion 21, and extends from the bottom plate 13, the front vertical plates 16 and 17, and A closed space (not shown) having a hollow box structure is formed between the swing brackets 18. As a result, the closing plate 25 increases the bonding strength and bending strength between the bottom plate 13, the front vertical plates 16 and 17, and the swing bracket 18, and forms the front side of the center frame 12 in a sturdy structure. .

  Reference numeral 26 denotes a horizontal plate which is positioned on the rear end side of the front vertical plates 16 and 17 and is erected on the bottom plate 13. The horizontal plate 26 is made of a steel plate or the like thinner than the bottom plate 13 and the front vertical plates 16 and 17. As shown in FIGS. 3 to 5, the upper surface of the bottom plate 13 and the rear ends of the front vertical plates 16 and 17 are joined to each other by welding means.

  The horizontal plate 26 connects the left and right front vertical plates 16 and 17 to each other on the bottom plate 13. Further, the horizontal plate 26 has a protruding portion 26A that protrudes toward the side frame 30 described later, and the distal end side of the protruding portion 26A is fixed to an intermediate portion in the length direction of the side frame 30 by means such as welding. It is what is done.

  Reference numerals 27 and 28 denote left and right rear vertical plates erected on the bottom plate 13 on the rear side of the horizontal plate 26. The rear vertical plates 27 and 28 extend left and right in front and rear of the bottom plate 13, respectively. The vertical plates 14 and 15 are configured together with the front vertical plates 16 and 17 described above.

  As shown in FIGS. 3 to 5, the rear vertical plates 27 and 28 are disposed so as to be separated to the left and right between the horizontal plate 26 and a weight mounting portion 29 to be described later. While being joined to the rear side, the rear end side is joined to the weight attaching portion 29. Further, the rear vertical plates 27 and 28 are arranged such that the front end side is joined to the horizontal plate 26 and the horizontal plate 26 is sandwiched between the rear ends of the front vertical plates 16 and 17 from the front and rear directions.

  Reference numeral 29 denotes a weight mounting portion fixed to the rear end side of the bottom plate 13 by means of welding or the like. The weight mounting portion 29 is composed of a plate material or the like extending left and right as shown in FIGS. 13 is provided between the rear upper surface of 13 and the rear ends of the rear vertical plates 27 and 28. A counterweight 7 shown in FIG. 1 is detachably attached to the weight attaching portion 29 using a bolt or the like.

  Reference numerals 30 and 31 denote left and right side frames (hereinafter referred to as a left side frame 30 and a right side frame 31) constituting a part of the turning frame 11, and the left side frame 30 and the right side frame 31 are crossed, for example. It is formed by bending a cylindrical hollow frame material having a D-shaped, quadrangular, triangular, circular or elliptical surface into an arc shape with reference to the turning center O shown in FIGS. ing.

  Here, the left side frame 30 includes a front frame portion 30A extending linearly in the left and right directions, and a joint frame 30B on one side (the left and right outer end portions) of the front frame portion 30A. The bent frame portion 30C is connected and the rear side is curved in an arc shape so as to fit within a virtual circle 32 having a radius R with respect to the turning center O shown in FIG.

  As shown in FIGS. 3 and 6, the front frame portion 30A of the left side frame 30 is fixed by fitting the inner end portions in the left and right directions to the fitting convex portion 23 of the swing bracket 18, and the bending frame. The rear end side of the portion 30 </ b> C is connected to the rear end side of the bottom plate 13 using a connection fitting 33 or the like. Further, the midway portion in the length direction of the bending frame portion 30C is connected to the middle portion in the length direction of the bottom plate 13 via a protruding beam 35 and the like which will be described later.

  In this case, in the left side frame 30, the outer end portion of the front frame portion 30A and the front end portion of the bent frame portion 30C connected via the joint portion 30B protrude outward from the virtual circle 32 having the radius R. . The left side frame 30 supports the cab 5 from below via a cab support plate 38 to be described later, and widens the living space in the cab 5 on the side of the joint portion 30B protruding outward from the virtual circle 32 having the radius R. Is.

  The right side frame 31 includes a short front frame portion 31A extending linearly in the left and right directions, and a joint portion 31B on one side (the outer end portion in the left and right directions) of the front frame portion 31A. And a bending frame portion 31C that is curved in an arc shape so as to be contained in a virtual circle 32 having a radius R shown in FIG.

  The front frame portion 31A of the right side frame 31 is fixed by fitting its inner end portion to the fitting convex portion 24 of the swing bracket 18, and the rear end side of the bending frame portion 31C is connected to the connecting bracket 34 or the like. Used to be connected to the rear end side of the bottom plate 13. Further, the middle portion in the length direction of the bending frame portion 31C is connected to the middle portion in the length direction of the bottom plate 13 through a protruding beam 36 and the like which will be described later.

  Reference numeral 35 denotes an extended beam for connecting the left side frame 30 to the center frame 12. The extended beam 35 is joined to the bottom plate 13 of the center frame 12 at the base end side, and the bent frame portion of the left side frame 30 at the distal end side. It is joined to 30C. The overhanging beam 35 increases the bonding strength of the left side frame 30 to the center frame 12 together with the protruding portion 26 </ b> A of the horizontal plate 26.

  Reference numeral 36 denotes an extended beam for connecting the right side frame 31 to the center frame 12. The extended beam 36 is joined to the bottom plate 13 of the center frame 12 at the base end side, and the bending frame portion of the right side frame 31 at the distal end side. It is joined to 31C. The overhanging beam 36 increases the bonding strength of the right side frame 31 with respect to the center frame 12.

  Reference numeral 37 denotes a mounting plate provided between the front vertical plate 17 of the center frame 12 and the right side frame 31. The mounting plate 37 is formed, for example, by bending a long and narrow steel plate into a crank shape. Is joined to the outer surface of the front vertical plate 17 at a position spaced upward from the bottom plate 13 of the center frame 12.

  Further, the distal end side of the mounting plate 37 is a bent plate portion 37A bent in a crank shape, and the distal end of the bent plate portion 37A is joined to the bent frame portion 31C of the right side frame 31 at a position lower than the base end side. Has been. A swing cylinder 44 described later is disposed with a gap between the crank-shaped mounting plate 37 and the front frame portion 31 </ b> A of the right side frame 31.

  Reference numeral 38 denotes a cab support plate provided on the front frame portion 30A of the left side frame 30 via a leg plate 39. The cab support plate 38 is located between the front vertical plate 17 and the leg plate 39 as shown in FIG. , Extending in the right direction, and supported on the upper plate portion 21 of the swing bracket 18 from the lower side by a receiving seat 22. The cab support plate 38 supports the floor (floor plate) side of the cab 5 shown in FIGS. 1 and 2 from the lower side together with other cab support plates (not shown).

  Reference numeral 40 denotes another mounting plate provided between the rear vertical plate 28 of the center frame 12 and the right side frame 31. The mounting plate 40 has an L-shaped planar shape as shown in FIGS. It comprises a bracket plate such as a steel plate, and constitutes a heat exchanger bracket on which a radiator 52 described later is mounted on the upper side.

  The base end side of the mounting plate 40 extends forward and rearward along the rear vertical plate 28 and is fixed to the rear vertical plate 28 by welding means or the like. The distal end side of the mounting plate 40 is a bent plate portion 40A bent in a crank shape, and the distal end of the bent plate portion 40A is joined to the bent frame portion 31C of the right side frame 31 at a position lower than the proximal end side. Yes.

  Further, a stopper 41 made of a plate material bent into a U-shape as shown in FIG. 9 is provided on the lower surface of the mounting plate 40. The stopper 41 attaches a bottom bracket 44A of a swing cylinder 44 described later to the cylinder. It supports so that it may pinch | interpose between the part 42 from the upper direction and the downward direction. 9 and 10, the stopper 41 is provided with an insertion hole 41A, and the upper end side of a connecting pin 45 described later is inserted into the insertion hole 41A.

  As a result, the mounting plate 40 serving as a heat exchanger bracket supports the bottom side bracket 44A of the swing cylinder 44 so as to be rotatable together with the connecting pin 45 using the stopper 41 positioned above the cylinder mounting portion 42. The side bracket 44 </ b> A is prevented from coming out from the upper end of the connecting pin 45.

  Reference numeral 42 denotes a cylinder mounting portion provided on the bottom plate 13 at a position outside the rear vertical plate 28. The cylinder mounting portion 42 is a block body whose planar shape is substantially U-shaped as shown in FIGS. The base end side is fixed to the outer surface of the rear vertical plate 28 using welding means or the like. Further, the cylinder mounting portion 42 extends along the upper surface of the bottom plate 13 in a direction substantially perpendicular to the outer surface of the rear vertical plate 28, and the tip side thereof is a position beyond a later-described attachment / detachment hole 43 as shown in FIG. Has reached.

  The lower surface side of the cylinder mounting portion 42 is joined to the upper surface of the bottom plate 13 using means such as fillet welding in a state where the attachment / detachment hole 43 of the bottom plate 13 is covered from above. The cylinder mounting portion 42 is provided with a pin hole 42A penetrating upward and downward at a position corresponding to the attachment / detachment hole 43, and a swing cylinder 44 described later is rotated in the pin hole 42A. A connecting pin 45 that can be pin-coupled is inserted.

  Further, as shown in FIGS. 8 and 10, a screw hole 42B is formed on the lower surface side of the cylinder mounting portion 42 at a position radially spaced from the pin hole 42A, and the connecting pin 45 is removed from the screw hole 42B. A fastening bolt 46, which will be described later, which is held in a stopped and non-rotating state, is screwed.

  43 is a detaching hole formed in the bottom plate 13 of the center frame 12 located below the cylinder mounting portion 42. The detaching hole 43 is eccentric from the center of the connecting pin 45 as shown in FIGS. It is formed as a non-circular hole (for example, a long hole), and the pin hole 42A of the cylinder mounting portion 42 is exposed (opened) to the lower surface side of the bottom plate 13 together with the screw hole 42B.

  And the removal | desorption hole 43 has a shape which can accommodate the collar part 45B of the connection pin 45 mentioned later in the rotation stop state. Further, the connecting pin 45 is inserted into and removed from the pin hole 42 </ b> A of the cylinder mounting portion 42 and the bottom side bracket 44 </ b> A of the swing cylinder 44 through the attachment / detachment hole 43.

  44 is a swing cylinder that swings the entire working device 8 left and right around the connecting pin 9 shown in FIG. 2, and the swing cylinder 44 has a bottom bracket 44A on the base end side as shown in FIGS. The bottom bracket 44A has a pin hole 44B through which the connecting pin 45 is inserted.

  Further, the swing cylinder 44 has a rod 44C that expands and contracts forward and backward by the supply and discharge of pressure oil. A swing post 8A of the working device 8 rotates on the tip side of the rod 44C as shown in FIGS. It is movably pinned. The swing cylinder 44 swings the entire working device 8 left and right around the connecting pin 9 shown in FIG. 2 by expanding and contracting the rod 44C.

  Reference numeral 45 denotes a connecting pin that rotatably connects the bottom bracket 44A of the swing cylinder 44 to the cylinder mounting portion 42 of the swing frame 11. The connecting pin 45 includes a pin shaft portion 45A and the pin as shown in FIG. The shaft portion 45A includes a flange portion 45B that protrudes in the radial direction from one end (lower end) side of the shaft portion 45A and is formed in a substantially oval plate shape, and a bolt insertion hole 45C is formed in the flange portion 45B. Yes.

  The pin shaft portion 45A of the connecting pin 45 is inserted into the pin hole 42A of the cylinder mounting portion 42 and the bottom bracket 44A (pin hole 44B) of the swing cylinder 44 as shown in FIGS. The tip (upper end) of 45A extends upward and downward to a position reaching the insertion hole 41A of the stopper 41 provided on the lower surface of the mounting plate 40.

  As a result, the connecting pin 45 pin-couples the bottom bracket 44A of the swing cylinder 44 so as to be rotatable with respect to the cylinder mounting portion 42, and the swing cylinder 44 moves the swing post 8A of the work device 8 to the left on the rod 44C side. This compensates for a smooth swinging operation to the right.

  The flange 45B of the connecting pin 45 is disposed in the attachment / detachment hole 43 of the bottom plate 13 as shown in FIGS. 7 and 10, and is inserted into the bolt insertion hole 45C in a state of abutting against the lower surface of the cylinder mounting portion 42. The cylinder bolt 42 is fixed in a non-rotating and retaining state by a fastening bolt 46 described later.

  46 is a fastening bolt as a fixing member for fixing the flange portion 45B of the connecting pin 45 to the lower surface side of the cylinder mounting portion 42. The fastening bolt 46 includes a cylindrical spacer 47 and a washer 48 as shown in FIGS. Is inserted into the bolt insertion hole 45C of the flange portion 45B via the screw and is screwed into the screw hole 42B of the cylinder mounting portion 42. As a result, the fastening bolt 46 is used to fix the flange 45 </ b> B of the connecting pin 45 to the lower surface side of the cylinder mounting portion 42 in the attaching / detaching hole 43 of the bottom plate 13, and fix it in a retaining state.

  Reference numeral 49 denotes an under cover provided on the lower surface side of the bottom plate 13, and the under cover 49 is formed in an outer shape as indicated by a two-dot chain line in FIG. The under cover 49 is located on the rear side of the overhanging beam 36 so as to cover the space formed between the bottom plate 13 of the center frame 12 and the bending frame portion 31C of the right side frame 31 from below. The bottom plate 13, the bending frame portion 31C, and the lower surface of the projecting beam 36 are detachably fixed using bolts 50 (only one is shown in FIG. 10) and the like.

  The under cover 49 partially covers the flange portion 45B of the connecting pin 45 disposed in the attaching / detaching hole 43 of the bottom plate 13 as shown in FIGS. 7 and 10, and the connecting pin 45 extends downward from the attaching / detaching hole 43. It also has a function to prevent accidental dropout. Note that another under cover (not shown) is provided on the front side of the overhanging beam 36 between the bottom plate 13 of the center frame 12 and the bending frame portion 31C of the right side frame 31.

  Reference numeral 51 denotes an engine as a prime mover mounted on the rear side of the bottom plate 13. The engine 51 is located at the rear side of the horizontal plate 26 as indicated by a two-dot chain line in FIG. It is attached on the top via a vibration-proof mount (not shown) or the like. The engine 51 rotates a hydraulic pump (not shown) or the like serving as a hydraulic pressure source.

  Reference numeral 52 denotes a radiator as a heat exchanger provided on the rear side of the bottom plate 13 together with the engine 51. The radiator 52 is located above the mounting plate 40 serving as a heat exchanger bracket in FIGS. 4, 9 and 10. It is mounted as shown by the two-dot chain line. And the radiator 52 cools the engine 51 using a cooling water.

  The rear small swing type hydraulic excavator 1 according to the present embodiment has the above-described configuration. Next, a method for assembling the swing frame 11 will be described.

  First, in the assembling process of the center frame 12, the left and right front vertical plates 16 on the upper surface side of the bottom plate 13 formed in a substantially rectangular shape from a thick steel plate or the like as shown in FIGS. 17 are welded together with the swing bracket 18, and the front end sides of the front vertical plates 16 and 17 are joined to the swing bracket 18 from the left and right sides by fillet welding or the like.

  In this case, the swing bracket 18 to which the swing post 8A of the working device 8 is pin-coupled is integrally formed in advance as a cast steel part composed of a cylindrical boss portion 19, a lower plate portion 20, and an upper plate portion 21. Then, the front end portion 13B of the bottom plate 13 is butt-welded to the front end side of the lower plate portion 20 extending rearward from the boss portion 19 as shown in FIG. Further, the front lower end sides of the front vertical plates 16 and 17 are joined to both the left and right sides of the lower plate portion 20 in an abutting state.

  Further, the upper side of the front vertical plates 16 and 17 are joined to the upper plate portion 21 of the swing bracket 18 by means such as fillet welding so that the flat surface portion 21A and the inclined surface portion 21B are sandwiched from both the left and right sides. . And it joins to the outer peripheral side of the boss | hub part 19 in the state which butted the front end side of the front vertical plates 16 and 17 as shown in FIG. 3, FIG.

  In addition, between the left and right front vertical plates 16 and 17, between the inclined surface portion 21B of the upper plate portion 21 and the bottom plate 13, a closing plate 25 is welded in a state inclined obliquely downward, Thereby, a closed space forming a box structure is formed between the bottom plate 13, the front vertical plates 16, 17 and the swing bracket 18.

  In this way, by using the closing plate 25 to form a closing space having a box structure on the front side of the revolving frame 11 (center frame 12), the above-described bottom plate 13, the front vertical plates 16 and 17, and the swing bracket are formed. The strength of the joint 18 and the bending strength are increased, and the front side of the center frame 12 is formed into a sturdy structure.

  On the other hand, on the rear side of the bottom plate 13, as shown in FIGS. 3 to 5, a horizontal plate 26 and left and right rear vertical plates 27 and 28 are erected by welding, respectively. On the rear side, a weight attaching portion 29 is provided on the rear end side of the bottom plate 13. The counterweight 7 shown in FIG. 1 can be detachably attached to the weight attachment portion 29 using a plurality of attachment bolts or the like.

  Also, a cylinder mounting portion 42 formed as a block body having a substantially U-shaped planar shape is provided on the rear side of the bottom plate 13, and the base end side of the cylinder mounting portion 42 is on the outer surface of the rear vertical plate 28. It is fixed by welding.

  In this case, the cylinder attachment portion 42 is fixed to the upper surface of the bottom plate 13 by fillet welding or the like in a state where the attachment / detachment hole 43 previously formed in the bottom plate 13 is covered from above, and pin holes 42A of the cylinder attachment portion 42 are provided. The screw hole 42B is exposed (opened) from the lower surface side of the bottom plate 13 through the attachment / detachment hole 43.

  Next, on the left and right sides of the center frame 12 assembled in this way, a left side frame 30 and a right side frame 31, as shown in FIGS. , 40 and the like by welding means or the like.

  In this case, the left side frame 30 is fixed by fitting the inner end portion of the front frame portion 30A to the fitting convex portion 23 of the swing bracket 18, and the rear end side of the bending frame portion 30C via the connecting metal fitting 33. The bottom plate 13 is connected to the rear end side. Further, the midway portion in the length direction of the bending frame portion 30C is integrally joined to the middle portion in the length direction of the bottom plate 13 via a protruding beam 35 or the like as shown in FIG.

  Further, the right side frame 31 is fixed by fitting the inner end portion of the front frame portion 31A to the fitting convex portion 24 of the swing bracket 18 and the rear end side of the bent frame portion 31C via the connecting bracket 34. 13 is connected to the rear end side. Further, the middle portion of the bending frame portion 31C in the length direction is integrally joined to the middle portion in the length direction of the bottom plate 13 through the protruding beam 36, the mounting plate 37, and the like as shown in FIGS.

  Between the rear vertical plate 28 of the center frame 12 and the bent frame portion 31C of the right side frame 31, as shown in FIGS. A mounting plate 40 is provided by welding or the like, and a radiator 52 illustrated in FIG. 4 can be mounted on the mounting plate 40 from above.

  Further, a stopper 41 made of a plate material bent into a U-shape as shown in FIG. 9 is provided on the lower surface of the mounting plate 40, and the bottom bracket 44 </ b> A of the swing cylinder 44 is connected to the cylinder mounting portion 42 by this stopper 41. Hold it from above and below.

  That is, when the bottom bracket 44A of the swing cylinder 44 is attached to the cylinder mounting portion 42 of the turning frame 11, the pin hole 42A of the cylinder mounting portion 42 and the pin hole 44B of the swing cylinder 44 are aligned. As shown in FIGS. 8 and 10, the connecting pin 45 is inserted into the pin holes 42 </ b> A and 44 </ b> B from the lower side of the bottom plate 13 through the attachment / detachment hole 43.

  And the collar part 45B of the connection pin 45 is arrange | positioned in the attachment / detachment hole 43 of the baseplate 13, The fastening bolt 46 is inserted in the bolt insertion hole 45C of this collar part 45B through the spacer 47 and the washer 48. Then, the fastening bolt 46 is screwed into the screw hole 42B of the cylinder mounting portion 42.

  Thus, the flange 45B of the connecting pin 45 can be stopped and fixed to the bottom surface side of the cylinder mounting portion 42 in the attaching / detaching hole 43 of the bottom plate 13 by using the fastening bolt 46. Further, the pin shaft portion 45 </ b> A of the connecting pin 45 is in a state where the upper end side is inserted into the insertion hole 41 </ b> A of the stopper 41 on the lower surface side of the mounting plate 40.

  As a result, the mounting plate 40 serving as the heat exchanger bracket can pivotally support the bottom bracket 44A of the swing cylinder 44 together with the connecting pin 45 using the stopper 41 positioned above the cylinder mounting portion 42. The side bracket 44 </ b> A can be prevented from coming out of the upper end of the connecting pin 45.

  Next, the operation of the rear small turning type hydraulic excavator 1 including the turning frame 11 assembled as described above will be described with reference to FIGS. 1 and 2.

  First, when the hydraulic pump is driven by the engine 51 housed in the exterior cover 6, the hydraulic oil from the hydraulic pump is supplied to and discharged from the traveling motor of the lower traveling body 2, so that the hydraulic excavator 1 (vehicle) moves forward. The vehicle can be driven to move backward.

  When excavation work such as earth and sand is carried out, the boom 8B and the arm 8C are moved up and down with respect to the swing post 8A by supplying and discharging the pressure oil from the hydraulic pump to each cylinder and the like of the work device 8. The bucket 8D is rotated while excavating earth and sand.

  Further, when performing, for example, a side ditching operation or the like using the working device 8, the rod 44C of the swing cylinder 44 is expanded and contracted by supplying and discharging the pressure oil, whereby the swing bracket 18 of the revolving frame 11 is shown in FIG. The swing post 8 </ b> A is swung horizontally (left and right) around the connecting pin 9, whereby the entire work device 8 is swung left and right with respect to the revolving frame 11.

  By the way, when performing maintenance such as maintenance and inspection of the swing cylinder 44, it is necessary to remove the connecting pin 45 provided on the bottom bracket 44A of the swing cylinder 44 from the pin hole 42A of the cylinder mounting portion 42. However, when the connecting pin 45 is inserted / removed above the cylinder mounting portion 42, it is not only necessary to remove the mounting plate 40 from the revolving frame 11, but also a hydraulic oil tank or a fuel tank ( Neither of them is shown), and the workability is deteriorated.

  Therefore, in the present embodiment, a demounting hole 43 including upper and lower through holes is provided in the bottom plate 13 of the revolving frame 11 at a position on the lower side of the cylinder mounting portion 42. The connecting pin 45 is inserted / removed downward from the pin holes 42 </ b> A and 44 </ b> B of the part 42 and the swing cylinder 44.

  Accordingly, when performing maintenance, inspection, etc. of the swing cylinder 44, the connecting pin 45 provided on the bottom bracket 44A of the swing cylinder 44 is connected to the pin of the cylinder mounting portion 42 by using the attachment / detachment hole 43 formed in the bottom plate 13. The hole 42A can be extracted downward.

  For this reason, at the time of maintenance and inspection of the swing cylinder 44, the troublesome work of removing the hydraulic oil tank and the like from the upper side of the revolving frame 11 as described in the prior art can be eliminated, and the connecting pin 45 can be connected to the revolving frame. The maintenance and inspection work of the swing cylinder 44 can be efficiently performed only by inserting / removing it below 11. And the maintainability of swing cylinder 44 can be improved and the workability | operativity can be improved significantly.

  Further, when the bottom bracket 44 </ b> A of the swing cylinder 44 is assembled to the cylinder mounting portion 42 of the revolving frame 11 via the connecting pin 45, the flange 45 </ b> B of the connecting pin 45 is stored in the attachment / detachment hole 43 of the bottom plate 13. It is possible to prevent the flange portion 45B of the connecting pin 45 from protruding downward from the lower surface of the turning frame 11.

  And the collar part 45B of the connection pin 45 can be fixed from the lower side using the fastening bolt 46 etc. to the lower surface side of the cylinder attachment part 42 in the state arrange | positioned in the attachment / detachment hole 43 of the baseplate 13, such fastening The connecting pin 45 can be prevented from being pulled out of the cylinder mounting portion 42 by a bolt 46 or the like, and can be held in a rotating state.

  Further, on the rear side of the bottom plate 13, a mounting plate 40 is provided between the rear vertical plate 28 and the right side frame 31 (bending frame portion 31 </ b> C) and serves as a bracket for the radiator 52. The stopper 41 provided on the lower surface side sandwiches the bottom bracket 44A of the swing cylinder 44 from above and below with the cylinder mounting portion 42, and supports the bottom bracket 44A so as to be rotatable together with the connecting pin 45. It is configured to do.

  Thus, the bottom bracket 44A of the swing cylinder 44 can be prevented from being accidentally detached from the pin shaft portion 45A of the connecting pin 45 by the stopper 41 of the mounting plate 40, and a part of the external force acting on the swing cylinder 44 can be restricted to the mounting plate. It can be received by the 40 stoppers 41, and the movement of the swing cylinder 44 can be stabilized.

Between the bending frame portion 31C of the bottom plate 13 and the right side frame 31 of the center frame 12 is positioned on the rear side of the projecting beam 36, these bottom plate 13, bent frame portion 31C and the overhang beam 36. An under cover 49 is detachably provided with a bolt 50 or the like so as to cover the space formed between the bottoms 36, and the under cover 49 is a flange portion of the connecting pin 45 disposed in the attachment / detachment hole 43 of the bottom plate 13. 45B is partially covered as shown in FIGS.

  For this reason, even if a stepping stone or the like is generated during traveling of the hydraulic excavator 1 and is flipped up to the lower surface side of the revolving frame 11, the under cover 49 is used to prevent the hook 45B or the like of the connecting pin 45 from the obstacle such as the stepping stone. It can protect, and it can prevent that the collar part 45B etc. collide with an obstacle etc., and is damaged and broken.

  Further, even if the fastening bolt 46 is loosened or damaged by an obstacle such as a stepping stone, the flange 45B of the connecting pin 45 can be held in the attachment / detachment hole 43 by the under cover 49, The connecting pin 45 can be prevented from accidentally falling downward from the attaching / detaching hole 43 of the bottom plate 13, and the connecting pin 45 can be kept in a detent state in the attaching / detaching hole 43.

  Next, FIG. 11 and FIG. 12 show a second embodiment of the present invention. The feature of this embodiment is that the flange portion of the connecting pin arranged in the attachment / detachment hole of the bottom plate is moved from the lower side by the under cover. It is in the structure which covered completely. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 61 denotes a cylinder mounting portion employed in the present embodiment. The cylinder mounting portion 61 is configured in substantially the same manner as the cylinder mounting portion 42 described in the first embodiment, and includes a pin hole 61A. And a screw hole 61B. However, the cylinder mounting portion 61 in this case is formed with a shallow counterbore 61C corresponding to a flange portion 62B of the connecting pin 62 described later on the lower surface side thereof.

  In this case, the counterbore 61C is formed to a depth that allows the head side of the fastening bolt 46 to be completely accommodated in the attachment / detachment hole 43 of the bottom plate 13 as shown in FIG. The head side is disposed so as not to protrude downward from the lower surface of the bottom plate 13 in the attachment / detachment hole 43 of the bottom plate 13.

  Reference numeral 62 denotes a connecting pin that rotatably connects the bottom bracket 44A of the swing cylinder 44 to the cylinder mounting portion 61. The connecting pin 62 is configured in substantially the same manner as the connecting pin 45 described in the first embodiment. The pin shaft portion 62A, the flange portion 62B, and the bolt insertion hole 62C are provided.

  Then, as shown in FIG. 12, the connecting pin 62 is inserted into the bolt insertion hole 62C in a state where the flange portion 62B is disposed in the attachment / detachment hole 43 of the bottom plate 13 and abuts against the counterbore hole 61C of the cylinder mounting portion 61. The fastening bolts 46 and the like are fixed to the cylinder mounting portion 61 in a non-rotating and retaining state.

  That is, the fastening bolt 46 is inserted into the bolt insertion hole 62C of the flange portion 62B via the cylindrical spacer 47 and the washer 48, and the fastening bolt 46 is screwed into the screw hole 61B of the cylinder mounting portion 61. . As a result, the fastening bolt 46 is fixed in a secured state in which the flange 62B of the connecting pin 62 is locked to the counterbore 61C side of the cylinder mounting portion 61 in the attaching / detaching hole 43 of the bottom plate 13.

  However, the connection pin 62 in this case is the first embodiment in that the length (axial dimension) of the pin shaft portion 62A is shortened by a dimension corresponding to the depth dimension of the counterbore 61C. This is a different form.

  Reference numeral 63 denotes an under cover provided on the lower surface side of the bottom plate 13. The under cover 63 is configured in substantially the same manner as the under cover 49 described in the first embodiment, and is located on the rear side of the overhanging beam 36. Bolts 50 (on the lower surfaces of the bottom plate 13, the bending frame portion 31C, and the overhanging beam 36 are respectively provided so as to cover the space formed between the bottom plate 13 of the frame 12 and the bending frame portion 31C of the right side frame 31 from below. In FIG. 12, only one is shown) and the like is detachably fixed.

  However, the under cover 63 in this case is formed in an outer shape as shown by a two-dot chain line in FIG. 11, and completely covers the removal hole 43 of the bottom plate 13 from the lower side and is disposed in the removal hole 43. The flange 62B of the connecting pin 62 is also configured to completely cover from below.

  Thus, even in the present embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment. However, in the present embodiment, the flange portion 62 </ b> B of the connecting pin 62 disposed in the attachment / detachment hole 43 of the bottom plate 13 is configured to be completely covered with the under cover 63 from below.

  As a result, even if a stepping stone or the like is generated during traveling of the hydraulic excavator 1 and is bounced up to the lower surface side of the revolving frame 11, such an obstacle such as a stepping stone collides with the flange 62B and the fastening bolt 46 of the connecting pin 62. This can be prevented by the under cover 63, and the flange 62B of the connecting pin 62 and the fastening bolt 46 can be protected from obstacles.

  In each of the above-described embodiments, the hydraulic excavator 1 including the box-shaped cab 5 that defines the cab inside is described as an example. However, the present invention is not limited to this, and for example, the operation driving unit on which the operator gets on and off may be configured to cover the driver's seat from above using a canopy.

  Further, in each of the embodiments, the description has been given by taking the small rear swivel excavator 1 as an example. However, the present invention is not limited to this. For example, the present invention may be applied to a swing frame of various construction machines provided with a swing post type working device.

1 is a front view showing a hydraulic excavator according to a first embodiment of the present invention. It is a top view of the hydraulic shovel shown in FIG. FIG. 2 is a plan view showing a turning frame in a state where a cab, an exterior cover, a counterweight, and the like in FIG. 1 are removed. FIG. 4 is an enlarged partial plan view showing a rear side of the center frame and the side frame in FIG. 3. It is the perspective view which looked at the turning frame in FIG. 3 from the rear upper part. It is the perspective view which looked at the turning frame of FIG. 3 from the bottom in the state which removed the undercover etc. It is a fragmentary perspective view which expands and shows the attachment / detachment hole in FIG. 6, the bottom side bracket of a swing cylinder, etc. It is a disassembled perspective view which shows the state which removed the connecting pin in FIG. 7 from a cylinder attaching part etc. FIG. FIG. 5 is an enlarged cross-sectional view of a cylinder mounting portion, a swing cylinder, a connecting pin, an under cover, and the like when viewed from the direction of arrows IX-IX in FIG. 4. It is an expanded sectional view which looked at a mounting plate, a cylinder mounting part, a swing cylinder, a connection pin, an undercover, etc. from the arrow XX direction in FIG. It is the perspective view in the same position as FIG. 7 which looked at the cylinder attaching part by 2nd Embodiment, a connection pin, an undercover, etc. from the lower side. It is sectional drawing in the position similar to FIG. 10 which shows the cylinder attaching part by 2nd Embodiment, a connection pin, an undercover, etc. FIG.

Explanation of symbols

1 Excavator (construction machine)
2 Lower traveling body 3 Swivel wheel 4 Upper revolving body 5 Cab 6 Exterior cover 7 Counterweight 8 Working device 8A Swing post 11 Swing frame 12 Center frame 13 Bottom plate 14, 15 Vertical plate 16, 17 Front vertical plate 18 Swing bracket 25 Closure plate 26 Horizontal plate 27, 28 Rear vertical plate 30, 31 Side frame 32 Virtual circle 35, 36 Overhang beam 40 Mounting plate (bracket for heat exchanger)
41 Stopper 42, 61 Cylinder mounting part 42A, 44B, 61A Pin hole 43 Detachment hole 44 Swing cylinder 44A Bottom side bracket 45, 62 Connecting pin 45A, 62A Pin shaft part 45B, 62B Hing part 46 Fastening bolt (fixing member)
49,63 Undercover 61C Counterbore O Rotation center R Radius

Claims (5)

A bottom plate provided on a lower traveling body via a turning wheel, left and right vertical plates standing upward from the bottom plate and extending in front and rear of the bottom plate, and the left and right vertical plates and the bottom plate A swing bracket that is provided on the front end side of the swing post and supports a swing post type work device so that it can swing left and right, and a swing cylinder that swings the work device left and right are rotated via a connecting pin. In order to enable mounting, in a swing frame of a construction machine comprising a cylinder mounting portion provided on the bottom plate located outside the left and right vertical plates,
The bottom plate is provided with a detaching hole for inserting and removing the connecting pin from the swing cylinder below the bottom plate, located below the cylinder mounting portion .
The connecting pin includes a pin shaft portion that is inserted into a pin hole provided in each of the bottom side of the swing cylinder and the cylinder mounting portion, and a flange portion that protrudes in a radial direction from one end portion of the pin shaft portion. A revolving frame for a construction machine, characterized in that the detaching hole of the bottom plate has a configuration in which a flange portion of the connecting pin is arranged inside . The flange portion of the connecting pin, the construction machine revolving frame according to claim 1 comprising a structure for fixing from below using a fixed member on the lower side of the cylinder mounting portion in a state of being arranged in the desorption hole of the bottom plate. The construction according to claim 1 or 2 , wherein the flange portion of the connecting pin has a non-circular outer shape, and the attachment / detachment hole of the bottom plate is formed in a hole shape that can accommodate the flange portion in a non-rotating state. Mechanical swivel frame. A heat exchanger bracket on which a heat exchanger for cooling a prime mover of a construction machine is mounted is provided on the bottom plate, and the heat exchanger bracket is located on the bottom side of the swing cylinder between the cylinder mounting portion. The revolving frame of the construction machine according to claim 1, 2 or 3 , wherein the frame is sandwiched from above and below so as to be rotatably supported using the connecting pin. An under cover extending to the position of the attachment / detachment hole is provided on the lower surface of the bottom plate, and the under cover is at least partially below the flange portion of the connection pin to prevent the connection pin from coming out from the attachment / detachment hole. The turning frame for a construction machine according to claim 1, 2 , 3, or 4 configured to cover from the side.

Images