JP4908141B2 - Construction machinery - Google Patents

Description

  The present invention relates to a construction machine such as a hydraulic excavator that is suitably used for excavating work such as earth and sand.

  Generally, a construction machine such as a hydraulic excavator is provided with a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a front and rear side of the upper revolving body that can be raised and lowered. It is comprised with the working apparatus which performs excavation work, such as earth and sand (for example, refer patent document 1).

  In this type of prior art hydraulic excavator, the working device is provided on the front side of the upper swing body so as to be pivotable and is lifted up and down by a boom cylinder, and the tip side of the boom And an arm that is pivoted up and down by an arm cylinder, and a bucket or the like that is provided on the distal end side of the arm via a link or the like and is rotated by a bucket cylinder.

  Further, the boom cylinder or the like of the working device includes a cylindrical tube that is a cylinder body, a piston that is slidably inserted into the tube and defines the inside of the tube into two oil chambers, and one end side is inside the tube. The other end side is constituted by a hydraulic cylinder which is inserted into the piston and fixed to the piston and which protrudes from the tube so as to expand and contract.

  On the other hand, a hydraulic cylinder used in such a working device is configured such that when an obstacle such as a stepping stone (sediment, rock) generated during excavation work collides with a protruding portion of the rod protruding from the tube, the protruding rod The parts may be worn and damaged at an early stage, causing a reduction in the life of the hydraulic cylinder.

  For this reason, in the prior art, a protective cover is provided on the protruding end side of the rod, the protruding portion of the rod is covered from the outside by the protective cover, and the rod is extended and contracted on the outer peripheral side of the tube. Accordingly, a guide member that slidably guides the free end side of the protective cover that is displaced in the length direction is provided (see, for example, Patent Document 2).

  The prior art disclosed in Patent Document 2 is applied to a small hydraulic excavator called a so-called small rear turning type, and employs a swing post type working device. In this case, the working device connects the boom to the swing frame of the upper swing body so as to be swingable left and right using a swing post. For example, when performing a side digging operation, the boom is attached to the swing frame. On the other hand, it is configured to swing (swing) left and right.

  On the other hand, as another conventional technique, for example, a fall prevention valve is provided between the boom cylinder and the hydraulic power source, and the boom prevention cylinder is operated by operating the fall prevention valve when the hydraulic piping (including the hydraulic hose) is damaged or damaged. There is also known a configuration in which the working device is prevented from falling to the ground side by being held in an oil lock state (see, for example, Patent Document 3).

JP 2001-317076 A JP 2002-220853 A JP 2003-253698 A

  By the way, in the above-described prior art, for example, when a product (hydraulic excavator) is transported using a trailer or a transport ship, the boom is swung downward to place the work device in a stable transport posture, and the tip of the work device A part (such as a link on the bucket side) is grounded to the ground or the like.

  However, in the case of such a conventional transporting posture, the boom, arm, etc. of the working device are greatly extended forward from the revolving frame of the upper revolving structure, so the occupied area (space) per product is large. It gets bigger. As a result, the number of products (hydraulic excavators) that can be mounted on a trailer, a transport ship, or the like is greatly limited, and there is a problem that the transport performance at the time of product shipment or the like deteriorates.

  Accordingly, the inventors of the present invention have reduced the occupation area per product by folding the arms and buckets of the working device to the boom side and raising the boom upward and standing up. It was investigated.

  However, in this case, since it is necessary to extend the boom cylinder greatly to hold the boom in an upright state, for example, it is required to support the weight of the entire working device, for example, 100 kg or more from below with the boom cylinder. In other words, there are the following unsolved problems.

  That is, the rod of the boom cylinder expands and contracts by supplying and discharging the pressure oil from the oil pressure source to the oil chamber in the tube. The boom cylinder cannot be kept in the extended position unless it is kept locked.

  However, since the directional control valve provided between the boom cylinder and the hydraulic power source has a sliding portion such as a spool, the pressure oil (hydraulic liquid) filled in the oil chamber of the boom cylinder is, for example, spool of the directional control valve. It is unavoidable to gradually leak from the sliding part. For this reason, for example, when transported by a transport ship for several weeks, the boom cylinder is gradually reduced from the extended position due to leakage of oil and the like, and it becomes difficult to keep the boom in the standing state as described above.

  If the boom tilts gradually downward from the standing position during transportation of the hydraulic excavator, multiple hydraulic excavators placed in a small occupied space may come into contact with each other or interfere with each other. Will occur, making it impossible to secure safe and secure transportation work.

  Moreover, even if a drop prevention valve is additionally provided between the boom cylinder and the hydraulic pressure source as in the prior art disclosed in Patent Document 3 described above, leakage of the oil liquid continues to be prevented for several weeks or more. This is difficult, and this also has the problem that safety during transportation cannot be ensured.

  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 reduce the occupied space per unit during transportation by holding the boom of the working device in an upright state. It is to provide a construction machine capable of improving the transport efficiency and transport performance of the machine and ensuring safe and secure transport work.

  Another object of the present invention is to use a rod protective cover provided on the boom cylinder to lock the boom cylinder in an extended state, for example, improving workability during transportation using a trailer, a transport ship, etc. It is to provide a construction machine that can be used.

In order to solve the above-described problems, the present invention provides a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a boom cylinder provided on the upper revolving body, Ri Do and a working device having a boom that is derricking motion down, wherein the working device, in a state where the upward Osshado by erecting the boom by a boom cylinder, the said boom cylinder is displaced in reduction direction It is applied to a construction machine provided with a regulating member that regulates .

The feature of the configuration adopted by the invention of claim 1 is that the boom cylinder includes a tube, a rod projecting from the tube so as to expand and contract, one side attached to the projecting end side of the rod, and the other side having a free end. It is a guide member for guiding the protective cover when the protective cover for protecting the rod from the outside, the free end of the protective cover provided in the tube is displaced relative to the tube, the protective cover Is provided with a bolt insertion hole located at the free end thereof, and the restricting member is disposed on the back side of the protective cover and contacts the contact surface of the guide member when the rod is displaced in the reduction direction. a stopper made of a plate member for regulating Te, a screw hole formed in the stopper, the rod the protective cover in a state of being largely extended from the tube of the boom cylinder Bol Through the insertion hole mounting the stopper to the protective cover by screwing the threaded hole of the stopper is constituted by a fastening bolt removably securing the said fastening bolt bolt insertion holes of the protective cover The stopper is attached to the protective cover and fixed so as to be removable by being screwed into the screw hole of the stopper .

  As described above, according to the first aspect of the present invention, the boom cylinder is prevented from being displaced in the reduction direction in a state where the boom of the working device is lifted upward from the upper swing body by the boom cylinder and is raised. For example, when a construction machine (product) such as a hydraulic excavator is transported by a trailer or a transport ship, the boom cylinder is displaced in the contracting direction with the boom of the working device raised upward. This can be restricted by the restriction member, and the boom cylinder can be prevented from being displaced for a long time due to leakage of the oil.

  Therefore, the boom can be held in an upright state even during the transportation of a product over a long period of time, the occupation area per product can be reduced, and a plurality of products (construction machinery) arranged in a narrow occupation space. ) Can be improved in safety and reliability during transportation work while preventing contact and interference with each other.

The protective cover for protecting the boom cylinder rod from external obstacles is provided with a bolt insertion hole located at its free end, and a regulating member is provided on the back side of the protective cover via the bolt insertion hole. Since it is configured to be provided, the boom cylinder can be locked in an extended state by utilizing a rod protective cover provided on the boom cylinder, and for example, workability during transportation using a trailer, a transport ship, or the like can be improved. .

Further, the prior SL boom cylinder, tube, rod, since the structure with a protective cover and the guide member, by providing detachably regulating member to the protective cover, a boom cylinder in the extended state by utilizing the protective cover For example, it is possible to improve workability during transportation using a trailer, a transport ship, or the like.

Also, when carrying out construction work, etc., with the rod of the boom cylinder greatly extended from the tube, a stopper as a restricting member is screwed into the screw hole formed in the stopper with respect to the protective cover. By fixing so as to be removable using a bolt, the stopper can be brought into contact with the guide member on the tube side to restrict the rod from being displaced in the reduction direction.

In this case, by forming the stopper as a plate extending along the protective cover, one side in the length direction of the stopper can be fixed to the back surface side of the protective cover facing the outer periphery of the rod using a fastening bolt. In addition, the other side in the length direction of the stopper can be disposed opposite to the guide member at a position on the outer peripheral side of the tube. In this state, when the other end surface of the stopper comes into contact with the guide member, the rod can be prevented from being further displaced in the reduction direction.

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

  Here, FIG. 1 to FIG. 11 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a hydraulic excavator of a small rear turning type. The hydraulic excavator 1 is mounted on a lower traveling body 2 capable of self-propelling in the front and rear directions and on the lower traveling body 2 so as to be swiveled. The upper revolving body 3 that constitutes the vehicle body of the excavator 1 together with the body 2, the working device 10 described later, and the like.

  Reference numeral 4 denotes a revolving frame that constitutes a frame of the upper revolving structure 3. The revolving frame 4 is integrally provided with a mounting bracket 4A on the front side thereof, and a working device 10 described later swings on the mounting bracket 4A. It is attached via a post 11 so as to be swingable in the left and right directions. A counterweight 5 is provided on the rear side of the swing frame 4, and the counterweight 5 balances the weight of the upper swing body 3 with the work device 10 on the front side.

  6 is an exterior cover provided on the revolving frame 4, and the exterior cover 6 is disposed on the upper side of the counterweight 5 so as to extend to the front side of the revolving frame 4 as shown in FIG. 1. . The exterior cover 6 is formed, for example, as a so-called bonnet that covers an engine as a prime mover, a heat exchanger such as a radiator, and a device such as a hydraulic pump as a hydraulic source (none of which is shown) from above. Is also used.

  A driver's seat 7 for an operator to sit on is provided on the upper side of the exterior cover 6. A floor board 8 is provided on the front side of the driver's seat 7 above the revolving frame 4, and the operator gets on the floor board 8 to board the driver's seat 7.

  Reference numeral 9 denotes a lever stand that is positioned on the floor plate 8 and is located on the front side of the driver's seat 7. The lever stand 9 has left and right traveling levers 9A that are tilted by an operator when the vehicle is traveling. And left and right work levers 9B that are operated when the upper swing body 3 is swung or the work device 10 is operated.

  Reference numeral 10 denotes a working device provided on the front side of the upper swing body 3 so as to be movable up and down. This working device 10 is mounted on a mounting bracket 4A of the swing frame 4 so as to be swingable left and right. 11, a boom 12 whose proximal end is attached to the swing post 11 so as to be able to move up and down, an arm 13 attached to the distal end side of the boom 12 so as to be able to move up and down, and pivotable to the distal end side of the arm 13 And a bucket 14 or the like as a work tool attached to the machine.

  A boom cylinder 15 is provided between the swing post 11 and the boom 12 of the work device 10 to move the boom 12 up and down relative to the revolving frame 4. In between, there is provided a swing cylinder or the like for swinging the entire working device 10 left and right with respect to the mounting bracket 4A of the revolving frame 4.

  An arm cylinder 16 that moves the arm 13 up and down is provided between the boom 12 and the arm 13 of the work apparatus 10, and the bucket 14 is rotated between the arm 13 and the bucket 14. A bucket cylinder 17 for moving is provided via links 18, 19 and the like.

  Here, the boom cylinder 15 includes a tube 20 whose lower end side (bottom side) is rotatably connected to the swing post 11, and is slidably fitted into the tube 20 so that two oil chambers are provided in the tube 20. A piston (not shown) which is defined in the figure, a rod 21 whose lower end is inserted into the tube 20 and fixed to the piston, and whose upper end protrudes from the tube 20 so as to be extendable and contractable, a protective cover 22 which will be described later, a support guide 24 and the like It is comprised by. And the protrusion end side of the rod 21 is connected with the bracket 12A of the boom 12 so that rotation is possible.

  Reference numeral 22 denotes a protective cover that constitutes a part of the boom cylinder 15. As shown in FIG. 5, the protective cover 22 has one side (upper end side) on the protruding end side of the rod 21 (a mounting eye or a mounting boss not shown). The other side (lower end side) is a free end that extends downward along the outer periphery of the tube 20.

  The protective cover 22 covers the protruding portion of the rod 21 that protrudes upward from the tube 20 from the outside, and thereby the protruding portion of the rod 21 is obstructed by, for example, a stepping stone generated due to excavation work or the like by the working device 10. It protects against an object (not shown). In this case, the protective cover 22 is formed, for example, by bending a steel plate made of a rigid body as shown in FIGS. 8 and 9, and its width dimension is larger than the outer diameter dimension of the tube 20 as shown in FIG. It is getting bigger.

  That is, the protective cover 22 is formed in an L shape from a guard plate portion 22A that extends in the length direction (axial direction) of the rod 21 while facing the outer peripheral surface of the rod 21, and from both sides in the width direction of the guard plate portion 22A. A pair of side plate portions 22B and 22B which are bent in two stages and have a U-shaped cross section, and projecting outward from the guard plate portion 22A in a triangular shape in cross section and extending over almost the entire length of the guard plate portion 22A. It is composed of reinforcing protrusions 22C, 22C and the like that are separated from each other in the width direction (left and right directions) of the portion 22A.

  Further, in the guard plate portion 22A of the protective cover 22, a bolt insertion hole 22D is drilled as shown in FIG. 7 and FIG. 8 at a site separated by a predetermined dimension in the length direction from the position of the end portion which becomes the free end. The bolt insertion hole 22D is disposed at a position between the protrusions 22C and 22C. A fastening bolt 28 described later is inserted through a washer 29 into the bolt insertion hole 22D of the protective cover 22.

  Reference numeral 24 denotes a support guide as a guide member fixed to the tube 20. The support guide 24 slides the free end (lower end) side of the protective cover 22 in the axial direction along the outer periphery of the tube 20. It is a guide that is movable. And the support guide 24 is comprised by the below-mentioned guide plate 25 and a pair of sliding body 26, as shown in FIG.6, FIG7 and FIG.9.

  Reference numeral 25 denotes a guide plate fixed to the outer peripheral surface of the tube 20. The guide plate 25 is a rectangular flat plate that extends in the width direction (left and right directions) of the protective cover 22 using a steel plate made of a rigid body. It is formed as a body. The guide plate 25 is fixed to the outer peripheral surface of the tube 20 by performing welding or the like in a state where the central portion is abutted against the outer peripheral surface of the tube 20.

  Further, as shown in FIG. 9, both side portions of the guide plate 25 are projecting portions 25A and 25A that project left and right from the tube 20, and a sliding body 26 described later is attached to each projecting portion 25A. Has been. Further, as shown in FIG. 6, the upper end surface of the guide plate 25 located between the projecting portions 25A and 25A serves as a contact surface 25B, and a stopper 27 abuts against the contact surface 25B as will be described later. The displacement of the boom cylinder 15 in the reduction direction is restricted.

  Reference numerals 26 and 26 denote a pair of sliding bodies constituting the support guide 24 together with the guide plate 25. Each of the sliding bodies 26 is substantially made of a resin material having excellent wear resistance and sliding characteristics such as high-density polyethylene. It is formed as a quadrangular bag-like body, and is mounted (fitted) so as to cover each projecting portion 25A of the guide plate 25 from the outside. These sliding bodies 26 cover the overhanging portion 25A of the guide plate 25 from the outside, and guide the free end side of the protective cover 22 to be slidable in the length direction of the tube 20.

  That is, each side plate portion 22B of the protective cover 22 is slidably fitted to each overhang portion 25A of the guide plate 25 from the outside of the slide body 26 as shown in FIG. It is displaced in the axial direction of the tube 20 in a state of dynamic contact. At this time, the protective cover 22 is restricted by the support guide 24 from being displaced in the radial direction of the tube 20, and smoothly slides and displaces in the axial direction of the tube 20.

  Reference numeral 27 denotes a stopper as a restricting member that is detachably provided on the protective cover 22. The stopper 27 is formed as a strip-shaped plate body using a steel plate or the like as shown in FIG. A screw hole 27A is formed. Further, the other side in the length direction of the stopper 27 is a contact portion 27B that can contact the contact surface 25B of the guide plate 25.

  Here, the stopper 27 is detachably fixed to the back side of the protective cover 22 in a state where the rod 21 of the boom cylinder 15 is greatly extended from the tube 20 as shown in FIG. 5, displacement in the direction of arrow A in FIG. 7 is controlled by the abutting portion 27 </ b> B coming into contact with the contact surface 25 </ b> B of the guide plate 25.

  That is, the stopper 27 is fixed to the back surface side of the protective cover 22 (guard plate portion 22A) facing the rod 21 in the radial direction using a fastening bolt 28 or the like as shown in FIG. The screw hole 27 </ b> A of the stopper 27 is screwed (tightened) through the bolt insertion hole 22 </ b> D of the protective cover 22.

  At this time, the abutting portion 27B of the stopper 27 is disposed so as to face the contact surface 25B of the guide plate 25 via a gap S (see FIG. 7), and the rod 21 exceeds the gap S in the direction of arrow A. The reduced displacement is restricted in cooperation with the contact surface 25B of the guide plate 25.

  In this case, it is not always necessary to form the gap S between the abutting portion 27B of the stopper 27 and the contact surface 25B of the guide plate 25. However, in order to fix the stopper 27 to the back side of the protective cover 22 using the fastening bolt 28, the assembly operation can be performed more easily by interposing the gap S. If the gap S in this case is also about 10 mm, for example, the boom cylinder 15 can be held at a position where it is substantially extended.

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

  First, the operator who has entered the floor board 8 of the upper swing body 3 drives the crawler belt of the lower travel body 2 by tilting the travel lever 9A on the lever stand 9 side while sitting on the driver's seat 7. can do.

  Further, when the upper swing body 3 is swung or the work device 10 is operated, the stopper 27 (see FIG. 7) is removed from the protective cover 22 in advance, so that the left and right work levers 9B are appropriately attached. When operated, for example, excavation work of earth and sand can be performed by swinging the boom 12 and the like up and down while swinging the entire working device 10 left and right via the swing post 11.

  That is, when the working device 10 is operated, the fastening bolt 28 is removed in advance from the protective cover 22 of the boom cylinder 15, and the stopper 27 and the like shown in FIG. 7 are removed from the protective cover 22. In this state, along with the expansion / contraction operation of the boom cylinder 15, the protective cover 22 is relatively displaced together with the rod 21 with respect to the tube 20, and the free end (lower end) side of the protective cover 22 is moved to the position shown in FIGS. And it can support so that sliding is possible by the support guide 24 shown in FIG.

  Therefore, when the boom cylinder 15 is displaced in the reduction direction as shown in FIG. 3, the free end side of the protective cover 22 is slid along the outer periphery of the tube 20 in the axial direction (length direction), and the tube 20 It is possible to continue to protect the protruding portion of the rod 21 protruding from the protective cover 22.

  Then, when the rod 21 of the boom cylinder 15 is greatly reduced as shown in FIG. 3, the working device 10 of the hydraulic excavator 1 causes the boom 12 to swing downward, for example, to ground the link 18 side to the ground or the like. In this state, the weight of the work device 10 can be prevented from acting on the boom cylinder 15.

  For this reason, when the excavator 1 (product) is transported using, for example, a trailer or a transport ship, the boom 12 is swung downward as shown in FIGS. 3 and 4 in order to place the working device 10 in a stable standby posture. In general, the distal end portion (for example, link 18) side of the working device 10 is grounded to the ground or the like.

  However, in such a standby posture, the boom 12, the arm 13 and the like of the work device 10 are greatly projected forward from the swing frame 4 of the upper swing body 3 as shown in FIGS. As shown in FIG. 12 as a comparative example, the occupation area (space) per product increases.

  As a result, if the work device 10 is placed in the standby posture, for example, the virtual parking space 100 indicated by a two-dot chain line in FIG. 12 is filled with the four hydraulic excavators 1, and the trailer or the transport ship The number of products (hydraulic excavator 1) that can be mounted on the vehicle is limited.

  Therefore, in the present embodiment, the arm 13 and the bucket 14 of the working device 10 are folded to the boom 12 side as shown in FIG. 1, and the boom 12 is lifted up and raised in this state. By restricting the displacement of the rod 21 of the boom cylinder 15 in the reduction direction using a stopper 27, a fastening bolt 28, and the like, the occupation area per product is reduced.

  That is, in the present embodiment, the boom 12 of the working device 10 is raised by the boom cylinder 15, and the protective cover 22 that protects the rod 21 of the boom cylinder 15 from the outside is provided as shown in FIGS. The stopper 27 is detachably attached using the fastening bolt 28.

  In this case, the stopper 27 is fixed to the back surface side of the protective cover 22 facing the outer periphery of the rod 21 using the fastening bolt 28, and the abutting portion 27 </ b> B of the stopper 27 is positioned at the position on the outer peripheral side of the tube 20. As shown in FIGS. 6 and 7, the contact surface 25B is arranged so as to be opposed to each other through a gap S (for example, S = about 5 to 10 mm).

  Thus, when the boom 21 is extended as shown in FIGS. 1 and 5 and the boom 12 is erected as shown in FIG. 1 and FIG. Even if the pressure oil in the tube 20 gradually leaks from a spool sliding portion (not shown) of the direction control valve, the reduction displacement of the boom cylinder 15 can be restricted as described below.

  That is, when the rod 21 of the boom cylinder 15 is reduced and displaced in the direction indicated by the arrow A by the gap S shown in FIG. 7, the abutting portion 27B of the stopper 27 contacts the contact surface 25B of the guide plate 25. Can be restricted by the stopper 27, and the rod 21 of the boom cylinder 15 can be held in a mechanically locked state.

  Then, by holding the boom 12 of the working device 10 in the standing state as shown in FIGS. 1 and 2, for example, the two hydraulic excavators 1 are opposed to each other as shown in FIG. The tip (bucket 14) side can be arranged side by side on the left and right.

  As a result, for example, four or more hydraulic excavators 1 can be arranged with sufficient clearance (margin) in the virtual parking space 100 indicated by the two-dot chain line in FIG. 11 and can be mounted on a trailer or a transport ship. The number of products (hydraulic excavator 1) transported can be reliably increased.

  Therefore, according to the present embodiment, when the hydraulic excavator 1 (product) is transported by a trailer, a transport ship, or the like, the boom cylinder 15 is displaced in the contracting direction with the boom 12 of the working device 10 raised in advance. This can be regulated by the stopper 27, and the reduction displacement of the boom cylinder 15 due to the leakage of the oil can be prevented over a long period of time.

  For this reason, the boom 12 can be held in an upright state during the transportation of the product for several weeks or more, and the occupied area per product can be reduced, and a plurality of products arranged in a narrow occupied space. It is possible to prevent (hydraulic excavator 1 and the like) from contacting and interfering before and after, and to improve safety and reliability during transportation work.

  As described above, in this embodiment, by holding the boom 12 of the working device 10 in an upright state, the occupied space per unit during transportation or the like can be reduced, and the transportation efficiency and transportation performance of the product can be improved. It can be improved and secure safe and secure transportation work.

  Further, when the boom 12 of the working device 10 is held in the standing state, the boom cylinder 15 can be locked in the extended state by using the protective cover 22 for the rod 21 provided in advance in the boom cylinder 15, for example, a trailer. In addition, workability during transportation using a transport ship or the like can be improved.

  On the other hand, when the transporting operation of the hydraulic excavator 1 is completed, the stopper 27 can be easily attached and detached by simply removing the fastening bolt 28 shown in FIG. 7 from the bolt insertion hole 22D of the protective cover 22. In the state where the stopper 27 is removed, the rod 21 of the boom cylinder 15 can be smoothly expanded and contracted, and the protective cover 22 is relatively displaced relative to the tube 20 along with this, by the support guide 24. Can be guided to.

  In addition, the stopper 27, the fastening bolt 28, and the washer 29 removed from the protective cover 22 at this time are small parts compared to the protective cover 22, the support guide 24, etc., and are stored for the next use, for example. Even in this case, the storage space can be reduced, and it is possible to easily cope with reuse.

  Next, FIG. 13 shows a second embodiment of the present invention. The feature of this embodiment is that a so-called offset boom type working device is configured to restrict the reduction displacement of the boom cylinder. 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 31 denotes a small swing type hydraulic excavator employed in the present embodiment. The hydraulic excavator 31 is a self-propelled lower traveling body 32 and an upper portion mounted on the lower traveling body 32 so as to be pivotable. The revolving body 33 and a working device 38, which will be described later, are configured.

  Here, the upper swing body 33 of the excavator 31 includes a cab 35 that defines a cab, an exterior cover 36 that houses an engine (not shown), a counterweight 37, and the like on a swing frame 34. Is provided. The turning frame 34 is provided with a mounting bracket (not shown) for rotatably supporting a boom 39 and the like which will be described later.

  Reference numeral 38 denotes an offset boom type working device provided on the swing frame 34 of the upper swing body 33 so as to be able to be lifted and lowered. The work device 38 is attached to the mounting bracket of the swing frame 34 so that the base end side can be lifted and lowered. A lower boom 39; an upper boom 40 attached to the tip of the lower boom 39 so as to swing left and right; and an arm stay 41 attached to the tip of the upper boom 40 so as to swing left and right The arm stay 41 includes an arm 42 attached to the arm stay 41 so as to be able to move up and down, and a bucket 43 as a work tool attached to the tip of the arm 42 so as to be rotatable.

  In the offset boom type working device 38, a link rod (not shown) is provided between the tip of the lower boom 39 and the arm stay 41 so as to be rotatable in the left and right directions. Yes. In this case, the link rod constitutes a parallel link together with the lower boom 39, the upper boom 40, and the arm stay 41, and the arm 42 (arm stay 41) is always held parallel to the lower boom 39 by the parallel link. Is.

  A boom cylinder 44 is provided between the turning frame 34 and the lower boom 39, and an arm cylinder 45 is provided between the arm stay 41 and the arm 42. A work implement bucket cylinder 48 is provided between the arm 42 and the bucket 43 via links 46 and 47.

  In addition, an offset cylinder (not shown) is provided between the lower boom 39 and the upper boom 40. For example, when the side groove is dug, the arm 42 extends and contracts the parallel link. The left and right are translated with respect to the lower boom 39.

  The boom cylinder 44 in this case is also configured in substantially the same manner as the boom cylinder 15 described in the first embodiment, and the tube 20, the rod 21, the protective cover 22, the fixing bolt 23, and the support guide 24 (see FIG. 7). ) Etc. Further, the protruding end side of the rod 21 is rotatably connected to a bracket 39A of the boom 39.

  When the arm 42 and bucket 43 of the working device 38 are folded to the upper boom 40 side as shown in FIG. As in the first embodiment, the stopper 27 (see FIG. 7) is fixed with the fastening bolts 28 as necessary, and the rod 21 of the boom cylinder 44 is restricted from being displaced in the reduction direction.

  Thus, in the present embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment, and it is possible to reduce the occupied space per unit at the time of transportation and the like to transport the product. Efficiency and transportation performance can be improved, and safe and secure transportation work can be secured.

Next, FIG. 14 shows a first reference example of the present invention. In this reference example , the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted. To do.

However, the feature of this reference example is that the protective cover 51 is detachably fixed to the guide plate 53 of the support guide 52 by the fixing bolt 55 in a state where the rod 21 of the boom cylinder 15 is greatly extended from the tube 20. That is, the fixing bolt 55 constitutes a restricting member.

  Here, the protective cover 51 is configured in substantially the same manner as the protective cover 22 described in the first embodiment, and includes a guard plate portion 51A, a side plate portion 51B, a reinforcing protrusion 51C, and the like. However, in this case, the protective cover 51 is provided with a bolt insertion hole 51D at a position spaced apart from the lower end position, which is the free end of the guard plate portion 51A, by a predetermined dimension in the length direction. The fixing bolt 55 is inserted through the washer 56.

  The support guide 52 fixed to the tube 20 is also composed of a guide plate 53 and a pair of sliding bodies 54 in substantially the same manner as the support guide 24 described in the first embodiment. However, the support guide 52 in this case has a screw hole 53A extending in the thickness direction at the center of the guide plate 53, and a fixing bolt 55 is screwed into the screw hole 53A as shown in FIG. It is.

Thus, also in this reference example configured as described above, the protective cover 51 is fixed to the guide plate 53 from the outside by using the fixing bolt 55 in a state where the rod 21 of the boom cylinder 15 is greatly extended from the tube 20. Thus, the rod 21 of the boom cylinder 15 can be locked in the extended state, and substantially the same operation and effect as in the first embodiment can be obtained.

In the first embodiment, the stopper 27 is attached to the protective cover 22 using the fastening bolts 28 to restrict the displacement of the rod 21 of the boom cylinder 15 in the reduction direction. And explained. On the other hand , in the second reference example shown in FIG. 15, for example, a rod-shaped regulating member 61 is detachably provided between the bracket 12A of the boom 12 and the swing post 11, and the rod 21 of the boom cylinder 15 is displaced in the reduction direction. from, Ru have a configuration in which regulated by the regulating member 61 of the rod-shaped.

  In the first embodiment, the so-called rear small turning type hydraulic excavator 1 provided with the swing post type working device 10 has been described as an example. However, the present invention is not limited to this, and can also be applied to a boom cylinder of a general working apparatus including a boom, an arm, and a bucket (working tool) such as a medium-sized or large-sized hydraulic excavator.

  Further, in each of the above embodiments, the small excavators 1 and 31 have been described as examples of the construction machine. However, the present invention is not limited to this, and can be applied to various construction machines including, for example, medium and large hydraulic excavators, hydraulic cranes, and the like.

1 is a front view showing a small 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 front view of a hydraulic excavator showing a state in which the working device in FIG. 1 is swung downward. FIG. 4 is a plan view of the hydraulic excavator shown in FIG. 3. It is the elements on larger scale which expand and show the working device in FIG. FIG. 6 is a partially cutaway side view of the boom cylinder protective cover and the like when viewed from the direction of arrows VI-VI in FIG. 5. It is sectional drawing which looked at the stopper etc. which were provided in the protective cover from the arrow VII-VII direction in FIG. It is a fragmentary perspective view which shows the protective cover in FIG. It is sectional drawing which looked at the support guide, stopper, etc. of the protective cover from the arrow IX-IX direction in FIG. It is a perspective view which shows the stopper in FIG. 6 alone. FIG. 3 is a plan view of a state where only a total of four hydraulic excavators shown in FIG. 2 are parked. It is a top view which shows the general parking state which parked only the hydraulic excavator of FIG. 4 in total as a comparative example. It is a front view which shows the small hydraulic excavator by 2nd Embodiment. It is sectional drawing in the same position as FIG. 7 which shows the state which fixed the protective cover to the guide plate with the fixing volt | bolt by a 1st reference example . It is a partial front view which shows the principal part of a working device in the state which attached the control member by the 2nd reference example to the boom cylinder side.

Explanation of symbols

1,31 Hydraulic excavator (Construction machinery)
DESCRIPTION OF SYMBOLS 2,32 Lower traveling body 3,33 Upper turning body 10,38 Work apparatus 11 Swing post 12 Boom 13,42 Arm 14,43 Bucket 15,44 Boom cylinder 20 Tube 21 Rod 22, 51 Protective cover 22D, 51D Bolt insertion hole 23 Fixing bolt 24, 52 Support guide (guide member)
25, 53 Guide plate 26, 54 Sliding body 27 Stopper (regulating member)
27A, 53A Screw hole 28 Fastening bolt (bolt)
39 Lower boom (boom)
40 Upper boom 55 Fixing bolt (regulating member)
61 Restriction member

Claims (1)

A working device having a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a boom that is provided on the upper revolving body and is lifted up and down by a boom cylinder. And consist of
In the construction machine provided with a restricting member for restricting the boom cylinder from being displaced in a contracting direction in a state where the boom is lifted upward and raised by the boom cylinder.
The boom cylinder includes a tube, a rod projecting from the tube so as to extend and contract, a protective cover that is attached to the projecting end side of the rod and has the other side as a free end to protect the rod from the outside, and the tube A guide member that guides the protective cover when the free end side of the protective cover is displaced relative to the tube,
The protective cover is provided with a bolt insertion hole located at its free end,
The restricting member is formed on the stopper and a stopper made of a plate body that is disposed on the back side of the protective cover and restricts the rod from being displaced in the reduction direction by abutting against the abutting surface of the guide member . The stopper is attached to and removed from the protective cover by screwing it into the screw hole of the stopper through the bolt insertion hole of the protective cover with the screw hole and the rod of the boom cylinder greatly extended from the tube. With fastening bolts that can be fixed ,
A construction machine characterized in that the stopper is attached to the protective cover and is detachably fixed by screwing the fastening bolt into the screw hole of the stopper through the bolt insertion hole of the protective cover. .

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