Pipe joining attachment for work machine, and work machine equipped with same

Abstract

To provide a lightweight pipe joining attachment for a work machine, which is connected to an arm of the work machine and ensures the strength required for joining pipes.SOLUTION: A work machine 1000 has a connection part 11 connected to an arm 1003 of the work machine, a holding part 12 for holding a pipe W1, a joined pipe contact part 16 which is located in the axial direction L of an insertion port W1a of the pipe W1 held by the holding part 12 relative to the holding part 12 and which contacts an outer peripheral surface of the joined pipe W2 to be joined to the pipe W1, and an escape mechanism 17 which can move the joined pipe contact part 16 in a direction in which the load F decreases when the joined pipe contact part 16 contacts the joined pipe W2 with a load F greater than a predetermined value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pipe joining attachment that is connected to the arm of a work machine and is used to join a pipe to a pipe to be joined, and to a work machine equipped with the same. [Background technology]

[0002] For example, in the installation of ductile cast iron pipes (an example of a water pipe) having a spigot and a socket, a pipe joining operation is performed to join a pipe to a pipe to be joined that is placed in an underground trench. In this pipe joining operation, a worker must first lower the pipe to be joined to the pipe to be joined into the trench. Then, the worker must align the pipe and the pipe to be joined in the trench, insert the spigot of the pipe into the socket of the pipe to join them.

[0003] In such a conventional pipe joining operation, the worker must lower the pipe into the groove while checking the position of the pipe relative to the pipe to be joined within the groove, and the worker must manually align the pipe and the pipe to be joined within the groove.

[0004] As described above, conventional pipe joining work places a heavy burden on the worker, and the workability in narrow trenches is not very good.

[0005] In response to this, for example, Patent Document 1 discloses a pipe laying machine in which a pipe holding body that is horizontally rotatable at the tip of an arm is equipped with a light receiver that receives laser light from a laser transmitter for pipe positioning, a pair of clamps with claws at both ends, and a roller for automatic centering of the pipe being laid. The laser transmitter is installed in the groove so that the laser light passes through the center of the pipe being laid. The light receiver is positioned at a position protruding from the pipe holding body so that it receives the laser light from the laser transmitter at the center of the pipe being laid.

[0006] The pipe laying machine can lower the laying pipe into the trench by moving the arms and the pipe holding body horizontally while holding the laying pipe with the pair of clamps. When lowering the laying pipe into the trench, the pipe laying machine moves the arms etc. to adjust the position of the laying pipe so that the laser from the laser transmitter hits the receiver.

[0007] This allows the pipe laying machine to lay the installation pipe in the trench safely and automatically without requiring anyone to enter the trench. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 6-323468 Summary of the Invention [Problem to be solved by the invention]

[0009] For example, when placing a pipe in an underground trench, the pipe may be positioned at an allowable bending angle relative to the pipe to be joined. When joining a pipe to a target pipe in an underground trench by bending it at a predetermined angle, one possible method is to provide a target pipe contact portion on a pipe joining attachment that joins the pipe to the target pipe, and to position the pipe at a desired angle relative to the target pipe by bringing the target pipe contact portion into contact with the outer circumferential surface of the socket side of the target pipe. By bringing the target pipe contact portion into contact with the target pipe, the pipe joining attachment can align the gripped pipe with reference to the outer circumferential surface of the socket side of the target pipe.

[0010] The pipe joining attachment configured in this manner is moved by a work machine to a position where the to-be-joined pipe contact portion contacts the to-be-joined pipe. When the to-be-joined pipe contact portion contacts the to-be-joined pipe, the pipe joining attachment is subjected to a force by the work machine pressing the to-be-joined pipe contact portion against the to-be-joined pipe. Therefore, it is desirable for the pipe joining attachment to be strong enough to withstand the force applied by the work machine when the to-be-joined pipe contact portion contacts the to-be-joined pipe.

[0011] Meanwhile, the pipe joining attachment must have a weight that can be carried by the work machine while holding the pipe. If the pipe joining attachment has the above-mentioned strength, the weight of the pipe joining attachment may increase and exceed the weight that can be carried by the work machine.

[0012] An object of the present invention is to provide a lightweight pipe joining attachment for a work machine that is connected to the arm of the work machine while ensuring the strength required for joining pipes. [Means for solving the problem]

[0013] A pipe joining attachment for a work machine according to one embodiment of the present invention comprises an arm connection portion connected to the arm of the work machine, a holding portion for holding the pipe, a joined pipe contact portion located in the axial direction of the insertion port of the pipe held by the holding portion relative to the holding portion and in contact with the outer surface of the receiving port side of the joined pipe to be joined to the pipe, and an escape mechanism that can move the joined pipe contact portion in a direction that reduces the load when the joined pipe contact portion contacts the joined pipe with a load greater than a predetermined value (first configuration).

[0014] The pipe connection attachment has a gripping portion that grips the pipe, and the fitting portion is brought into contact with the outer surface of the socket of the pipe, making it easy to position the pipe insertion port relative to the socket of the pipe. Furthermore, if a load greater than a predetermined value is applied to the fitting portion, the relief mechanism moves the fitting portion, thereby reducing the load applied to the pipe connection attachment.

[0015] With the above-described configuration, the pipe joining attachment does not need to have strength that takes into account the maximum force applied from the work machine, making it possible to realize a lightweight pipe joining attachment for a work machine that ensures the strength required for joining pipes.

[0016] In the first configuration, the relief mechanism includes a frame portion that movably supports the joined pipe contact portion, and a position holding portion that switchably holds the joined pipe contact portion between a pipe joining position when joining the pipe to the joined pipe, and a release position moved from the pipe joining position in a direction in which the load is reduced (second configuration).

[0017] As described above, the pipe contact portion to be joined is held switchably between the pipe joining position and the detached position relative to the frame portion, so that even if a load greater than a predetermined value is applied to the pipe contact portion to be joined, the load greater than the predetermined value will not be applied to the frame portion. Furthermore, the pipe contact portion to be joined that has been moved to the detached position can be switched to the pipe joining position. This makes it possible to realize a pipe joining attachment for a work machine that has a lightweight configuration while ensuring the strength required for joining pipes, and that can be used repeatedly even if a load greater than a predetermined value is applied to the pipe contact portion to be joined.

[0018] In the second configuration, the relief mechanism has a lift-up prevention mechanism that prevents the joined pipe contact portion from lifting up from the frame portion when it comes into contact with the joined pipe (third configuration).

[0019] This prevents the position of the pipe-to-be-connected contact portion from shifting relative to the holding portion when the pipe held by the holding portion is aligned with the pipe-to-be-connected by the pipe-to-be-connected contact portion. Therefore, the pipe joining attachment having the above-described configuration can improve the accuracy of alignment between pipes.

[0020] In the second or third configuration, the position holding portion has a movement limiting member that limits movement of the joined pipe contact portion until a load greater than a predetermined value is applied to the joined pipe contact portion (fourth configuration).

[0021] This allows the pipe-to-be-connected contact portion to be positioned at the pipe joining position even if a load of a predetermined value or less is applied to the pipe-to-be-connected contact portion. In other words, the pipe joining attachment only needs to have the strength to be able to join pipes when a load of a predetermined value or less is applied to the pipe-to-be-connected contact portion. Therefore, it is possible to realize a lightweight pipe joining attachment for a work machine that ensures the strength required for joining pipes.

[0022] In the second or third configuration, the position maintaining portion has a pressing portion that presses the joined pipe contact portion against the frame portion so that a predetermined value of frictional force is generated between the frame portion and the joined pipe contact portion (fifth configuration).

[0023] This allows the pipe-to-be-joined contact portion to be held in the pipe joining position until a load exceeding a predetermined frictional force is applied between the frame portion and the pipe-to-be-joined contact portion. In other words, the pipe joining attachment only needs to have the strength to be able to join pipes when a load of a predetermined value or less is applied to the pipe-to-be-joined contact portion. This makes it possible to realize a lightweight pipe joining attachment for a work machine that ensures the strength required for joining pipes.

[0024] A work machine according to one embodiment of the present invention has a pipe connecting attachment for a work machine having any one of the first to third configurations, and an arm to the tip of which the pipe connecting attachment is attached (sixth configuration).

[0025] This makes it possible to realize a work machine equipped with a pipe connecting attachment having any one of the first to third configurations. Therefore, using the work machine, it is possible to easily position the pipe insertion port relative to the socket port of the pipe to be connected. [Effects of the Invention]

[0026] A pipe joining attachment for a work machine according to one embodiment of the present invention comprises an arm connection portion connected to the arm of the work machine, a holding portion for holding the pipe, a joined pipe contact portion located in the axial direction of the insertion port of the pipe held by the holding portion relative to the holding portion and in contact with the outer surface of the receiving port of the joined pipe to be joined to the pipe, and an escape mechanism that can move the joined pipe contact portion in a direction that reduces the load when the joined pipe contact portion contacts the joined pipe with a load greater than a predetermined value.

[0027] As a result, when a load greater than a predetermined value is applied to the pipe contact portion to be joined, the load applied to the pipe joining attachment can be reduced by the movement of the pipe contact portion by the relief mechanism. Therefore, with the above configuration, it is not necessary to provide strength that takes into account the maximum force applied from the work machine. Therefore, it is possible to realize a lightweight pipe joining attachment for a work machine while ensuring the strength necessary for joining pipes. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a work machine to which a pipe connecting attachment according to a first embodiment is connected. [Figure 2] FIG. 2 is a view of the pipe joining attachment as seen from one side in the width direction. [Figure 3] FIG. 3 is a view of the pipe joining attachment as seen from one side in the axial direction. [Figure 4] FIG. 4 is a view of the pipe joining attachment as seen from the other side in the axial direction. [Figure 5]FIG. 5 is a diagram showing a typical state in which a pipe is being transported when a pipe and a pipe to be joined are joined using a pipe joining attachment. [Figure 6] FIG. 6 is a diagram schematically showing a state in which the pipe-to-be-connected contact portion is positioned at a joining position when a pipe and a pipe to be connected are joined using a pipe joining attachment. [Figure 7] FIG. 7 is a diagram schematically showing a state in which the to-be-connected pipe contact portion has moved to a release position when a pipe and a to-be-connected pipe are joined using a pipe joining attachment. [Figure 8] FIG. 8 is a diagram schematically showing how the pipe-to-be-connected contact portion is moved to a joining position when joining a pipe and a pipe-to-be-connected using a pipe joining attachment. [Figure 9] FIG. 9 is a view of the pipe joining attachment according to the second embodiment as seen from one side in the axial direction. [Figure 10] FIG. 10 is a partial cross-sectional view of the pipe joining attachment according to the third embodiment, as viewed from one side in the width direction. [Figure 11] FIG. 11 is a view of a pipe joining attachment according to another embodiment, viewed from one side in the width direction. DETAILED DESCRIPTION OF THE INVENTION

[0029] Each embodiment will be described below with reference to the drawings. In each drawing, the same parts are designated by the same reference numerals, and the description of the same parts will not be repeated. Note that the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0030] In the following description, the front, rear, left, and right directions respectively refer to the front, rear, left, and right directions as seen by the operator operating the work machine 1000. The axial direction refers to the direction in which the axis L of the pipe W1 gripped by the pipe joining attachments 1, 100, and 200 extends. The width direction refers to a horizontal direction that is perpendicular to the axial direction. The horizontal direction includes not only the strictly horizontal direction but also a direction that intersects with the up-down direction.

[0031] Furthermore, in the following description, the expressions "fix," "connect," and "attach" (hereinafter referred to as "fixing") include not only cases where members are directly fixed to each other, but also cases where members are fixed via other members. In other words, in the following description, the expression "fixing" includes both direct and indirect fixing of members to each other.

[0032] [Embodiment 1] (Work machinery) FIG. 1 is a diagram showing a schematic configuration of a work machine 1000 connected to a pipe joining attachment 1 according to a first embodiment of the present invention. The pipe joining attachment 1 is connected to the tip of an arm 1003 of the work machine 1000. The work machine 1000 can perform a variety of construction works and tasks by changing the attachment connected to the tip of the arm 1003. In this embodiment, the work machine 1000 is, for example, a mini backhoe, which is a construction machine used for excavation.

[0033] Note that work machine 1000 may be a construction machine other than a mini backhoe, and may be a machine with any configuration as long as it is capable of operating pipe connection attachment 1.

[0034] As shown in Figure 1, the work machine 1000 is capable of traveling in the front-to-rear direction and of rotating horizontally about a rotation axis P that extends in the up-and-down direction. The work machine 1000 can be driven, for example, by hydraulic pressure. However, the work machine may also be driven, for example, by an electric motor.

[0035] The work machine 1000 has a work machine body 1001 , a boom 1002 , and an arm 1003 .

[0036] The work machine main body 1001 has an upper rotating body 1011 and a lower traveling body 1012. The upper rotating body 1011 can rotate horizontally around a rotation axis P. The lower traveling body 1012 has an annular caterpillar track and can travel in the front-to-rear direction.

[0037] The boom 1002 is a beam-shaped member extending forward from the upper rotating body 1011. One end of the boom 1002 is connected to the upper rotating body 1011. The boom 1002 is rotatable in the vertical direction relative to the upper rotating body 1011, with the one end as the center.

[0038] The arm 1003 is a beam-shaped member having one end connected to the front end of the boom 1002. The arm 1003 is rotatable in the vertical direction around the one end relative to the boom 1002. An attachment can be connected to the other end of the arm 1003. In this embodiment, a pipe joining attachment 1 is connected to the other end of the arm 1003.

[0039] The boom 1002 and the arm 1003 can be driven by hydraulic cylinders (not shown), or may be driven by an electric motor or the like.

[0040] The pipe connecting attachment 1 may be connected to the other end of the arm 1003 via an attachment mounting member. The attachment mounting member is configured so that an attachment can be easily mounted on the other end of the arm 1003.

[0041] The construction of the work machine body 1001, boom 1002 and arm 1003 of the work machine 1000 is the same as that of the conventional construction, and therefore detailed description thereof will be omitted.

[0042] (pipe connection attachment) 2 to 5 are diagrams showing the general configuration of the pipe joining attachment 1. FIG. 2 is a view of the pipe joining attachment 1 as seen from one side in the width direction. FIG. 3 is a view of the pipe joining attachment 1 as seen from one side in the axial direction. FIG. 4 is a view of the pipe joining attachment 1 as seen from the other side in the axial direction. FIG. 5 is a diagram showing the pipe W1 being transported when joining the pipe W1 and the pipe to be joined W2 using the pipe joining attachment 1. The general configuration of the pipe joining attachment 1 will be described below with reference to FIGS. 2 to 5.

[0043] In the following description, the pipe W1 and the connected pipe W2 (see FIGS. 2 to 8) are preferably earthquake-resistant pipes having earthquake-resistant joints that can be bent at a predetermined angle. Note that the pipe W1 and the connected pipe W2 may be pipes other than earthquake-resistant pipes.

[0044] The pipe joining attachment 1 is configured to be able to grip the pipe W1, and is able to rotate the gripped pipe W1 horizontally around a rotation axis Q extending in the vertical direction and move it in the axial direction of the pipe W1. As shown in Figures 2 to 5, the pipe joining attachment 1 has an arm connection part 11, a gripping part 12, an axial movement mechanism 13, a horizontal rotation mechanism 14, a support part 15, a joined pipe contact part 16, and a relief mechanism 17.

[0045] The arm connection part 11 is located at the upper end of the pipe joining attachment 1, and is connected to the other end of the arm 1003 of the work machine 1000. The arm connection part 11 may be connected to the other end of the arm 1003 by a bolt or a pin, or may be fitted with a fitting part. The arm connection part 11 may be connected to the other end of the arm 1003 by any configuration.

[0046] The gripping portion 12 is supported by an axial movement mechanism 13 (described later) so as to be movable in the axial direction. The gripping portion 12 grips the pipe W1. The gripping portion 12 has a pair of gripping claws 21 and a gripping drive portion 22.

[0047] The pair of gripping claws 21 are positioned side by side in the width direction perpendicular to the axial direction so as to be able to grip the pipe W1. One end of the pair of gripping claws 21 is connected to a gripping drive unit 22. The pair of gripping claws 21 can rotate around the one end in directions moving toward and away from each other relative to the gripping drive unit 22. The pair of gripping claws 21 clamp the pipe W1 in the width direction.

[0048] In this embodiment, the gripping portion 12 has two pairs of gripping claws 21. The two pairs of gripping claws 21 are arranged side by side with respect to the gripping drive portion 22 in the axial direction of the pipe W1.

[0049] The gripping drive unit 22 applies a driving force to one end of the pair of gripping jaws 21 such that the pair of gripping jaws 21 rotate around the one end in a direction in which they move toward and away from each other. The gripping drive unit 22 may generate the driving force using hydraulic pressure output from the work machine 1000, for example, or may generate the driving force using an electric motor or the like.

[0050] The axial movement mechanism 13 is supported by a horizontal rotation mechanism 14 (described later) so as to be rotatable in the horizontal direction about a rotation axis Q. The axial movement mechanism 13 moves the gripping portion 12 in the axial direction of the pipe W1 gripped by the gripping portion 12. The axial movement mechanism 13 has a guide portion 31, a slider 32, and an axial drive portion 33.

[0051] The guide unit 31 is connected to the horizontal rotation mechanism 14, which will be described later, so as to be rotatable in the horizontal direction about a rotation axis Q. The guide unit 31 has, for example, a pair of guide rails 31a extending along the axis L of the pipe W1. That is, the pair of guide rails 31a extend in the axial direction. Therefore, in this embodiment, the longitudinal direction of the pair of guide rails 31a coincides with the axial direction. The guide rails 31a are H-shaped steel beams having flanges that protrude widthwise at the top and bottom when viewed in the axial direction. Note that the guide rails 31a may be members other than H-shaped steel beams.

[0052] The slider 32 is provided relative to the guide portion 31 so as to be movable in the longitudinal direction of the guide portion 31, i.e., in the axial direction. The slider 32 is formed with a generally U-shaped cross section so as to cover the lower and side surfaces of the pair of guide rails 31a of the guide portion 31. That is, the slider 32 has a bottom surface 32a and a pair of side surfaces 32b extending upward from the bottom surface 32a. Rollers 32c are rotatably supported on the pair of side surfaces 32b of the slider 32. The rollers 32c move by rolling on the flanges of the pair of guide rails 31a.

[0053] The axial drive unit 33 can move the slider 32 relative to the guide unit 31 in the longitudinal direction of the guide unit 31, i.e., in the axial direction. For example, the axial drive unit 33 is a hydraulic cylinder. This hydraulic cylinder is supplied with hydraulic pressure output from, for example, the work machine 1000. Although not specifically shown, the cylinder tube of the hydraulic cylinder is fixed to the guide unit 31 via a support unit 15 that supports the joined pipe contact portion 16, which will be described later. The piston rod of the hydraulic cylinder is fixed to the slider 32. The hydraulic cylinder is arranged to extend in the longitudinal direction of the guide unit 31, i.e., in the axial direction. Therefore, the slider 32 can be moved relative to the guide unit 31 by moving the piston rod of the hydraulic cylinder in the axial direction relative to the cylinder tube.

[0054] This allows the pipe W1 gripped by the gripping portion 12 of the pipe joining attachment 1 to be moved in the axial direction. Therefore, the pipe joining attachment 1 makes it easy to position the insertion port W1a of the pipe W1 relative to the socket W2a of the pipe to be joined W2 (see Figures 6 to 8), and also makes it easy to insert the insertion port W1a of the pipe W1 into the socket W2a of the pipe to be joined W2.

[0055] The horizontal rotation mechanism 14 is connected to the arm 1003 of the work machine 1000 via the arm connection part 11. That is, the arm connection part 11 is fixed to the upper part of the horizontal rotation mechanism 14. An axial drive part 33 is connected to the lower part of the horizontal rotation mechanism 14 so as to be rotatable in the horizontal direction around the rotation axis Q.

[0056] As a result, the horizontal rotation mechanism 14 can rotate the pipe connecting attachment 1 horizontally about the rotation axis Q relative to the arm 1003 of the work machine 1000. Therefore, the pipe W1 gripped by the gripping portion 12 of the pipe connecting attachment 1 can be moved into an underground trench or the like without moving or rotating the work machine 1000.

[0057] The support part 15 is fixed to, for example, the guide part 31 of the axial movement mechanism 13. The support part 15 has a support body 15a and a connection support part 15b. The support body 15a is flat and is fixed to the guide part 31 of the axial movement mechanism 13. The connection support part 15b is a pair of flat plate-like members that extend downward and forward from the support body 15a. The connection support part 15b is fixed to the support body 15a. The connection support part 15b supports a frame part 171 of the escape mechanism 17.

[0058] The to-be-joined pipe contact portion 16 is fixed to the axial movement mechanism 13 by the support portion 15 so as to be positioned in the axial direction of the insertion port W1a of the pipe W1 relative to the gripping portion 12. The to-be-joined pipe contact portion 16 contacts the socket W2a side of the to-be-joined pipe W2 when positioning the insertion port W1a of the pipe W1 gripped by the gripping portion 12 relative to the socket W2a of the to-be-joined pipe W2. Note that the socket W2a side of the to-be-joined pipe W2 includes not only the socket W2a of the to-be-joined pipe W2 but also the socket W2a side of the pipe body of the to-be-joined pipe W2.

[0059] The joined pipe contact portion 16 has a main body portion 16a and a contact portion 16c. The main body portion 16a is flat and extends downward when viewed in the axial direction. The main body portion 16a has a pair of guide grooves 16b, which are elongated holes extending vertically. The guide grooves 16b are located parallel to each other on both the left and right sides of the main body portion 16a. The contact portion 16c is flat and has a pair of contact portions 16c whose upper ends are connected and whose lower ends are spaced apart in the width direction. In other words, the contact portions 16c are formed in an inverted V shape, with the spacing between the contact portions 16c increasing downward. The upper ends of the contact portions 16c are fixed to the lower end of the main body portion 16a. The joined pipe contact portion 16 is supported by a relief mechanism 17 so as to be movable vertically.

[0060] Because the connected pipe contact portion 16 has this configuration, even if the outer diameter of the connected pipe W2 on the receiving port W2a side is different, the contact portion 16c of the connected pipe contact portion 16 can be brought into contact with the outer peripheral surface of the connected pipe W2 on the receiving port W2a side.

[0061] When viewed in the axial direction of the socket W2a of the to-be-connected pipe W2, the pair of contact portions 16c of the to-be-connected pipe contact portion 16 contact a portion of the outer peripheral surface of the to-be-connected pipe W2 on the socket W2a side that is positioned diagonally relative to the width direction (for example, at 45 degrees relative to the width direction). This positions the pipe connecting attachment 1 in the width direction and in a direction perpendicular to the width direction relative to the socket W2a of the to-be-connected pipe W2.

[0062] The pair of contact portions 16c of the to-be-joined pipe contact portion 16 may contact a portion of the outer peripheral surface of the to-be-joined pipe W2 on the socket W2a side that is located on one side or the other in the width direction, or may contact a portion of the outer peripheral surface of the to-be-joined pipe W2 on the socket W2a side that is located in a direction perpendicular to the width direction. In other words, when viewing the socket W2a in the axial direction of the to-be-joined pipe W2, the to-be-joined pipe contact portion 16 may contact a portion of the outer peripheral surface of the to-be-joined pipe W2 on the socket W2a side that is located in at least one of the width direction and the direction perpendicular to the width direction. One of the pair of contact portions 16c of the to-be-joined pipe contact portion 16 may contact the outer peripheral surface of the to-be-joined pipe W2 on the socket W2a side.

[0063] The relief mechanism 17 can move the to-be-connected pipe contact portion 16 in a direction that reduces the load F so that a load F greater than the maximum allowable load Ft is not applied to the to-be-connected pipe contact portion 16 when the to-be-connected pipe contact portion 16 comes into contact with the to-be-connected pipe W2. The maximum allowable load Ft is the load applied to the to-be-connected pipe contact portion 16 when the force transmitted from the to-be-connected pipe contact portion 16 in contact with the to-be-connected pipe W2 to the pipe connecting attachment 1 becomes the maximum allowable load of the pipe connecting attachment 1 when aligning the insertion port W1a of the pipe W1 with the receiving port W2a of the to-be-connected pipe W2. The relief mechanism 17 has a frame portion 171 and a position holding portion 172.

[0064] The frame portion 171 is flat and fixed to the tip ends of the pair of connection support portions 15b. The frame portion 171 is positioned so that its plane is perpendicular to the axial direction. That is, the frame portion 171 is fixed to the tip end of the connection support portion 15b with its plane facing forward. The frame portion 171 has a pair of guide portions 171a. The pair of guide portions 171a are rod-shaped and fixed to the plane of the frame portion 171 at a distance from each other on the left and right. The guide portions 171a extend forward from the frame portion 171. The guide portions 171a are each inserted into the guide grooves 16b of the joined pipe contact portion 16. The plane of the frame portion 171 is in contact with the plane of the main body portion 16a of the joined pipe contact portion 16. Therefore, the frame portion 171 supports the joined pipe contact portion 16 so that it can be guided in the up and down direction by the guide portions 171a.

[0065] The position holding unit 172 holds the to-be-connected pipe contact portion 16 switchably between a pipe joining position P1 when joining the pipe W1 to the to-be-connected pipe W2, and a release position P2, which is moved from the pipe joining position P1 in the direction in which the load F decreases. The pipe joining position P1 is the position of the to-be-connected pipe contact portion 16 when the guide portion 171a of the frame portion 171 is in contact with the upper end of the guide groove 16b of the to-be-connected pipe contact portion 16. The release position P2 is any position of the to-be-connected pipe contact portion 16 when the guide portion 171a of the frame portion 171 is separated from the upper end of the guide groove 16b of the to-be-connected pipe contact portion 16. The position holding unit 172 has a toggle clamp 172a and a pressing plate 172b.

[0066] The toggle clamp 172a utilizes a toggle mechanism to press a pressing plate 172b against the joined pipe contact portion 16. The toggle clamp 172a is fixed to the frame portion 171. The toggle clamp 172a has a pressing plate 172b fixed to its output portion. By operating the input portion, the toggle clamp 172a can be switched between a pressing state in which the pressing plate 172b of the output portion is pressed against the joined pipe contact portion 16, and a separating state in which the pressing plate 172b is separated from the joined pipe contact portion 16.

[0067] In the pressed state, the toggle clamp 172a uses the pressing plate 172b to press the flat surface of the to-be-connected pipe contact portion 16 against the flat surface of the frame portion 171. The position of the pressing plate 172b of the toggle clamp 172a is adjusted so that, in the pressed state, a predetermined value of frictional force μF is generated between the flat surface of the to-be-connected pipe contact portion 16 and the flat surface of the frame portion 171. Specifically, the position of the pressing plate 172b of the toggle clamp 172a is adjusted so that a frictional force μF is generated between the to-be-connected pipe contact portion 16 and the frame portion 171 that is equal to or greater than the minimum frictional force capable of holding the position of the to-be-connected pipe contact portion 16 relative to the frame portion 171 and is less than the maximum allowable load Ft. In other words, the range of the frictional force μF is set to a range that is greater than the weight of the to-be-connected pipe contact portion 16 and is less than the maximum allowable load of the pipe connecting attachment 1 when the to-be-connected pipe contact portion 16 contacts the to-be-connected pipe W2. In a pressed state, the toggle clamp 172a holds the joined pipe contact portion 16 so that when a load F exceeding the friction force μF is applied upward to the joined pipe contact portion 16, the joined pipe contact portion 16 moves upward relative to the frame portion 171.

[0068] 6 to 8, the state of the to-be-connected pipe contact portion 16 that comes into contact with the to-be-connected pipe W2 when the pipe W1 and the to-be-connected pipe W2 are joined together will be described. FIG. 6 is a diagram schematically illustrating a state in which the to-be-connected pipe contact portion 16 is located at the pipe joining position P1 when the pipe W1 and the to-be-connected pipe W2 are joined together using the pipe joining attachment 1. FIG. 7 is a diagram schematically illustrating a state in which the to-be-connected pipe contact portion 16 has moved to the release position P2 when the pipe W1 and the to-be-connected pipe W2 are joined together using the pipe joining attachment 1. FIG. 8 is a diagram schematically illustrating the state in which the to-be-connected pipe contact portion 16 is moved to the pipe joining position P1 when the pipe W1 and the to-be-connected pipe W2 are joined together using the pipe joining attachment 1.

[0069] 6, when a load F of less than or equal to the frictional force μF is applied from below to above the to-be-joined pipe contact portion 16 that is in contact with the to-be-joined pipe W2 when joining the pipe W1 and the to-be-joined pipe W2, the to-be-joined pipe contact portion 16 is held at the pipe joining position P1 by the position holding portion 172 in which the toggle clamp 172a is in the pressing state. At this time, a load within the allowable range of the pipe joining attachment 1 (less than the maximum allowable load Ft) is transmitted from the to-be-joined pipe contact portion 16 to the pipe joining attachment 1.

[0070] As shown in Figure 7, when joining pipe W1 and target pipe W2, if a load F greater than the friction force μF is applied from below to above the target pipe contact portion 16, the position of the joining pipe contact portion 16 slides upward relative to the frame portion 171 and switches to the release position P2. At this time, the maximum load within the allowable range of the pipe joining attachment 1 is transmitted from the target pipe contact portion 16 to the pipe joining attachment 1. Note that the release position P2 is located above the pipe joining position P1 so that the load F applied to the target pipe contact portion 16 is reduced.

[0071] As shown in Figure 8, when joining a pipe W1 and a to-be-joined pipe W2, if the toggle clamp 172a is switched from the pressed state to the separated state while the to-be-joined pipe contact portion 16 is separated from the to-be-joined pipe W2, gravity will cause the to-be-joined pipe contact portion 16 to switch from the detached position P2 to a pipe joining position P1 located downward.

[0072] In this way, the position holding portion 172 is configured as a pressing portion that presses the joined pipe contact portion 16 against the frame portion 171 so that a predetermined value of friction force μF is generated between the frame portion 171 and the joined pipe contact portion 16 by the toggle clamp 172a.

[0073] As described above, by positioning the pipe joining attachment 1 in the width direction and in a direction perpendicular to the width direction relative to the pipe W2 to be joined, the insertion port W1a of the pipe W1 held by the holding portion 12 of the pipe joining attachment 1 can be positioned in the width direction and in a direction perpendicular to the width direction relative to the receiving port W2a of the pipe W2 to be joined.

[0074] When the receiving port W2a of the to-be-connected pipe W2 is viewed in the axial direction, the width direction of the to-be-connected pipe W2 corresponds to the first direction, and the direction perpendicular to the width direction corresponds to the second direction. When the axis M of the to-be-connected pipe W2 is parallel to the axis L of the pipe W1 and the axes L and M extend horizontally, the direction perpendicular to the width direction is the up-down direction.

[0075] Furthermore, when the pipe-to-be-joined contact portion 16 of the pipe joining attachment 1 comes into contact with the pipe-to-be-joined W2 from above with a load F greater than the friction force μF, the escape mechanism 17 can move the pipe-to-be-joined contact portion 16 upward so that the load F decreases.

[0076] As described above, the pipe joining attachment 1 of the work machine 1000 in this embodiment has an arm connection portion 11 connected to the arm 1003 of the work machine 1000, a holding portion 12 that holds the pipe W1, a joined pipe contact portion 16 that is positioned relative to the holding portion 12 in the axial direction of the insertion port W1a of the pipe W1 held by the holding portion 12 and that contacts the outer surface of the receiving port W2a side of the joined pipe W2 to be joined to the pipe W1, and an escape mechanism 17 that can move the joined pipe contact portion 16 in the direction that reduces the load F when the joined pipe contact portion 16 contacts the joined pipe W2 with a load F greater than a predetermined value.

[0077] When aligning the insertion port W1a of the pipe W1 held by the pipe joining attachment 1 attached to the arm 1003 of the work machine 1000 with the receiving port W2a of the pipe to be joined, if a load F greater than the friction force μF is applied to the contact portion 16 of the pipe to be joined, the load applied to the pipe joining attachment 1 can be reduced by moving the contact portion 16 of the pipe to be joined by the release mechanism 17.

[0078] Therefore, with the above-described configuration, the pipe joining attachment 1 does not need to have strength that takes into account the maximum force applied from the work machine 1000. This makes it possible to simplify the frame structure of the pipe joining attachment 1. This makes it possible to realize a lightweight pipe joining attachment 1 for a work machine that ensures the strength required to join the pipe W1.

[0079] In this embodiment, the relief mechanism 17 has a frame portion 171 that movably supports the joined pipe contact portion 16, and a position holding portion 172 that switchably holds the joined pipe contact portion 16 between a pipe joining position P1 when joining the pipe W1 to the joined pipe W2, and a release position P2 moved from the pipe joining position P1 in the direction in which the load F decreases.

[0080] As described above, the joined pipe contact portion 16 is held switchably between the pipe joining position P1 and the release position P2 relative to the frame portion 171, so even if a load F greater than a predetermined value is applied to the joined pipe contact portion 16, the load greater than the predetermined value will not be applied to the frame portion 171. Furthermore, the joined pipe contact portion 16 that has moved to the release position P2 can be switched to the pipe joining position P1. This makes it possible to realize a pipe joining attachment 1 for a work machine 1000 that has a lightweight configuration while ensuring the strength required to join the pipe W1, and that can be used repeatedly even if a load F greater than a predetermined value is applied to the joined pipe contact portion 16.

[0081] In this embodiment, the position holding portion 172 has a toggle clamp 172a and a pressing plate 172b, which are pressing portions that press the joined pipe contact portion 16 against the frame portion 171 so that a predetermined value of friction force μF is generated between the frame portion 171 and the joined pipe contact portion 16.

[0082] As a result, the friction force μF generated between the frame portion 171 and the to-be-joined pipe contact portion 16 can hold the to-be-joined pipe contact portion 16 at the pipe joining position P1 until a load F greater than a predetermined value is applied. In other words, the pipe joining attachment 1 only needs to have the strength to enable pipe joining when a load F of a predetermined value or less is applied to the to-be-joined pipe contact portion 16. Therefore, it is possible to realize a pipe joining attachment 1 for the work machine 1000 that is lightweight while ensuring the strength required to join the pipe W1.

[0083] A work machine 1000 according to this embodiment has a pipe joining attachment 1 having the configuration of this embodiment, and an arm 1003 to the tip of which the pipe joining attachment 1 is attached.

[0084] This makes it possible to realize a work machine 1000 equipped with a pipe joining attachment 1 having the configuration of this embodiment. Therefore, using the work machine 1000, the insertion port W1a of the pipe W1 can be easily positioned relative to the socket W2a of the joined pipe W2.

[0085] [Embodiment 2] Fig. 9 shows a schematic configuration of a pipe connecting attachment 100 according to embodiment 2. Fig. 9 is a view of the pipe connecting attachment 100 as seen from one side in the axial direction.

[0086] The relief mechanism 17 includes a frame portion 171 , a position holding portion 172 , and a lift-up prevention mechanism 173 .

[0087] The lift-up prevention mechanism 173 prevents the joined pipe contact portion 16 from lifting up from the frame portion 171 when the joined pipe contact portion 16 comes into contact with the joined pipe W2. The lift-up prevention mechanism 173 is removably fixed to a pair of guide portions 171a of the frame portion 171, which is a flat plate-like member wider than the width of the guide groove 16b.

[0088] The lift-up prevention mechanism 173 contacts the flat surface of the joined pipe contact portion 16 while allowing the joined pipe contact portion 16 to move up and down. In other words, the lift-up prevention mechanism 173 restricts movement of the joined pipe contact portion 16 in the axial direction of the guide portion 171a. Therefore, the lift-up prevention mechanism 173 suppresses movement of the joined pipe contact portion 16 so that the joined pipe contact portion 16 does not lift up from the frame portion 171 when the joined pipe contact portion 16 moves.

[0089] As described above, the pipe joining attachment 100 of this embodiment has a lift-up prevention mechanism 173 that prevents the joined pipe contact portion 16 from lifting up from the frame portion 171 when it comes into contact with the joined pipe W2.

[0090] The anti-floating mechanism 173 having this configuration can prevent the position of the to-be-connected pipe contact portion 16 from shifting relative to the gripping portion 12 when the pipe W1 held by the gripping portion 12 is aligned with the to-be-connected pipe W2 by the to-be-connected pipe contact portion 16. Therefore, the pipe connecting attachment 100 having the above configuration can improve the accuracy of alignment between the pipe W1 and the to-be-connected pipe W2.

[0091] [Embodiment 3] Fig. 10 shows a schematic configuration of a pipe connecting attachment 200 according to embodiment 3. Fig. 10 is a partial cross-sectional view of the pipe connecting attachment 200 as seen from one side in the width direction.

[0092] The relief mechanism 17 includes a frame portion 171 and a position holding portion 272 .

[0093] The position holding portion 272 holds the joined pipe contact portion 16 switchably between a pipe joining position P1 when joining the pipe W1 to the joined pipe W2, and a release position P2 moved from the pipe joining position P1 in a direction in which the load is reduced. The position holding portion 272 has a movement limiting member 272a.

[0094] The movement limiting member 272a is a pin that limits the movement of the to-be-connected pipe contact portion 16 until a load F greater than a predetermined breaking force Fb is applied to the to-be-connected pipe contact portion 16. The movement limiting member 272a is inserted into a through hole 171b in the frame portion 171 and a through hole 16d in the connecting pipe contact portion 16. When the to-be-connected pipe contact portion 16 is located at the pipe connecting position P1, the through hole 16d overlaps with the through hole 171b when viewed in the axial direction. Therefore, the movement limiting member 272a holds the to-be-connected pipe contact portion 16, which is located at the pipe connecting position P1, relative to the frame portion 171.

[0095] The movement limiting member 272a is formed so as to break when a load F greater than the breaking force Fb is applied to the joined pipe contact portion 16. Specifically, the movement limiting member 272a has an annular slit on its outer circumferential surface. The movement limiting member 272a is inserted into the through hole 171b so that the annular slit is positioned between the joined pipe contact portion 16 and the frame portion 171. The movement limiting member 272a is configured so as to break from the annular slit when a load F greater than the breaking force Fb is applied upward to the joined pipe contact portion 16.

[0096] Therefore, the movement limiting member 272a can hold the joined pipe contact portion 16 at the pipe joining position P1 relative to the frame portion 171. Furthermore, when a load F greater than the breaking force Fb is applied from below to above the joined pipe contact portion 16, the position holding portion 272 can be switched from the pipe joining position P1 to a release position P2 moved upward, where the load F applied to the joined pipe contact portion 16 decreases.

[0097] As described above, the position holding portion 272 of the pipe joining attachment 200 of this embodiment has a movement limiting member 272a that limits the movement of the joined pipe contact portion 16 until a load F greater than a predetermined value is applied to the joined pipe contact portion 16.

[0098] With the movement limiting member 272a configured as described above, when a load of less than or equal to the breaking force Fb is applied to the to-be-connected pipe contact portion 16, the to-be-connected pipe contact portion 16 can be positioned at the pipe connecting position P1. In other words, the pipe connecting attachment 200 only needs to have the strength to enable pipe joining when a load F of less than or equal to the breaking force Fb is applied to the to-be-connected pipe contact portion 16. Therefore, it is possible to realize a lightweight pipe connecting attachment 200 for the work machine 1000 that ensures the strength required to join the pipe W1 and the to-be-connected pipe W2.

[0099] (Other embodiments) Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and it is possible to appropriately modify the above-described embodiments within the scope of the spirit of the present invention.

[0100] In each of the above-described embodiments, the pipe joining attachments 1, 100, and 200 have the axial movement mechanism 13 and the horizontal rotation mechanism 14. However, the pipe joining attachment does not necessarily have to have at least one of the axial movement mechanism and the horizontal rotation mechanism.

[0101] In each of the above-described embodiments, the arm connecting portion 11 is located at the upper end of the pipe connecting attachment 1, 100, 200. However, the arm connecting portion may be located at a position other than the upper end of the pipe connecting attachment.

[0102] In each of the above-described embodiments, the gripping portion 12 has a pair of gripping claws 21. However, the gripping portion may have other configurations, such as a suction mechanism, as long as it is configured to be able to grip a tube.

[0103] In each of the above-described embodiments, the pair of gripping claws 21 of the pipe joining attachments 1, 100, and 200 are positioned side by side in the width direction perpendicular to the axial direction. However, the pair of gripping claws may be positioned at positions offset in the vertical direction or in the axial direction.

[0104] In each of the above-described embodiments, the gripping portion 12 has two pairs of gripping claws 21. However, the gripping portion may have three or more pairs of gripping claws.

[0105] In each of the above-described embodiments, the guide portion 31 of the pipe joining attachment 1, 100, 200 has, for example, a pair of guide rails 31a extending along the axis L of the pipe W1. However, the guide portion may have one or three or more guide rails. The guide portion may have a configuration other than guide rails as long as the slider is configured to be movable in the axial direction.

[0106] In each of the above-described embodiments, the slider 32 of the pipe joining attachment 1, 100, 200 is a member having a generally U-shaped cross section, which has a bottom surface 32a and a pair of side surfaces 32b extending upward from the bottom surface 32a. However, the slider may have any shape, such as a flat plate or a block, as long as the slider is configured to allow the gripping portion 12 to move axially relative to the guide portion.

[0107] In each of the above-described embodiments, the axial drive unit 33 is a hydraulic cylinder. However, the axial drive unit may be a drive device other than a hydraulic cylinder, such as an electric actuator, as long as it has a configuration that allows the slider to move axially relative to the guide unit.

[0108] In each of the above embodiments, the to-be-connected pipe contact portion 16 is formed in an inverted V-shape. However, the to-be-connected pipe contact portion may also be formed in an inverted U-shape that opens downward. In this case, the distance between the pair of straight portions constituting the inverted U-shaped to-be-connected pipe contact portion is dimensioned to allow the insertion of the socket side of the pipe body of the to-be-connected pipe. The to-be-connected pipe contact portion may have a shape other than a V-shape, such as an L-shape, an inverted L-shape, or a T-shape, as long as it contacts the socket side of the to-be-connected pipe and allows the pipe connecting attachment to be positioned in the width direction and in the direction perpendicular to the width direction relative to the socket of the to-be-connected pipe. The to-be-connected pipe contact portion may also have a shape (such as a straight, flat, or curved shape) that contacts the socket side of the to-be-connected pipe and allows the pipe connecting attachment to be positioned in the width direction and in the direction perpendicular to the width direction relative to the socket of the to-be-connected pipe.

[0109] In each of the above-described embodiments, the position holding unit 172 uses the frictional force generated by the pressing of the toggle clamp 172a to hold the connected pipe contact portion 16 switchably between the pipe connecting position P1 and the release position P2. However, the position holding unit may also use an actuator such as an electric motor, hydraulic motor, or pneumatic motor to switchably hold the connected pipe contact portion 16 between the pipe connecting position P1 and the release position P2.

[0110] In each of the above-described embodiments, the position-retaining portion 172 is configured such that the toggle clamp 172a generates a friction force μF between the frame portion 171 and the to-be-joined pipe contact portion 16 that is equal to or greater than the minimum friction force capable of retaining the position of the to-be-joined pipe contact portion 16 relative to the frame portion 171 and less than the maximum allowable load Ft. However, the position-retaining portion 172 may also be configured such that the combined friction force μF of the friction force between the frame portion 171 and the to-be-joined pipe contact portion 16 and the friction force between the press plate 172b and the to-be-joined pipe contact portion 16 is equal to or greater than the minimum friction force capable of retaining the position of the to-be-joined pipe contact portion 16 relative to the frame portion 171 and less than the maximum allowable load Ft.

[0111] In each of the above-described embodiments, the position maintaining portion 172 of the release mechanism 17 uses a pin, which is a movement limiting member 272a, to limit the movement of the joined pipe contact portion 16 relative to the frame portion 171. However, the position maintaining portion may also be a movement limiting member that limits the movement of the joined pipe contact portion when a load of a predetermined value or less is applied, such as a plunger, compression spring, or clutch.

[0112] In each of the above-described embodiments, the pipe joining attachments 1, 100, and 200 may have an elastic support portion that elastically supports the gripping portion 12 and the joined pipe contact portion 16 in the vertical direction. For example, as shown in FIG. 11 , the pipe joining attachment 200 may have an elastic support portion 70 between the horizontal rotation mechanism 14 and the axial movement mechanism 13 that elastically supports the axial movement mechanism 13 in the vertical direction relative to the horizontal rotation mechanism 14. The elastic support portion 70 includes, for example, a spring or rubber member that connects the horizontal rotation mechanism 14 and the axial movement mechanism 13. This allows the gripping portion 12, which is supported by the axial movement mechanism 13 so as to be axially movable, and the joined pipe contact portion 16, which is supported by the guide portion 31 of the axial movement mechanism 13, to be elastically supported in the vertical direction relative to the horizontal rotation mechanism 14 by the elastic support portion 70. Therefore, when the pipe W1 is held by the holding portion 12 and the connected pipe contact portion 16 comes into contact with the outer peripheral surface of the socket W2a side of the connected pipe W2, the impact applied to the pipe connecting attachment 200 can be reduced. [Industrial Applicability]

[0113] The present invention can be used in a pipe joining attachment that is connected to the arm of a work machine and is used to join a pipe to a pipe to be joined. [Explanation of symbols]

[0114] 1, 100, 200 Pipe Joint Attachment 11 Arm connection part 12 Grip part 13 Axial movement mechanism 14 Horizontal rotation mechanism 15 Support part 15a Support body 15b Connection support part 15c Guide support part 16 Pipe contact part to be joined 16a Main body 16b Guide groove 16c Contact part 17 Escape mechanism 171 Frame section 16d, 171b through hole 172, 272 Position holding part 172a toggle clamp 172b Pressing plate 173 Anti-floating mechanism 272a Movement restriction member 21 Gripping claw 22 Gripping drive unit 31, 171a Guide section 31a Guide rail 32 slider 32a Bottom 32b side 32c Lola 33 Axial drive unit 70 Elastic support part 1000 Work Machines 1001 Work machine body 1002 Boom 1003 Arm 1011 Upper rotating body 1012 Lower running body W1 tube W1a socket W2 Joined pipe W2a socket P, Q rotation axis L, M axis P1 joint position P2 Detachment position F load Ft Maximum allowable load μF Frictional force

Claims

1. a connection portion connected to an arm of the work machine; a gripping portion that grips the tube; a connecting pipe contact portion that is located in the axial direction of the insertion port of the pipe gripped by the gripping portion and that contacts the outer peripheral surface of the connecting pipe to be connected to the pipe; a relief mechanism that, when a load greater than a predetermined value is applied by the contact portion of the pipe to be joined coming into contact with the pipe to be joined, causes the contact portion of the pipe to move in a direction opposite to the acting direction of the load, thereby reducing the load applied to the pipe to be joined; having An attachment for connecting pipes on work machines.

2. 2. The pipe connecting attachment for a work machine according to claim 1, The relief mechanism includes: a frame portion that movably supports the joined pipe contact portion; a position holding portion that holds the to-be-joined pipe contact portion switchably between a pipe joining position when joining the pipe to the to-be-joined pipe and a release position moved from the pipe joining position in a direction opposite to the acting direction of the load; having An attachment for connecting pipes on work machines.

3. 3. The pipe connecting attachment for a work machine according to claim 2, The relief mechanism includes: a lift-up prevention mechanism that prevents the joint pipe contact portion from lifting up from the frame portion when the joint pipe contact portion comes into contact with the joint pipe; An attachment for connecting pipes on work machines.

4. The pipe connecting attachment for a work machine according to claim 2 or 3, The position maintaining unit is a movement limiting member that limits movement of the contact portion of the pipe to be joined until a load greater than the predetermined value is applied to the contact portion of the pipe to be joined; An attachment for connecting pipes on work machines.

5. The pipe connecting attachment for a work machine according to claim 2 or 3, The position maintaining unit is a pressing portion that presses the to-be-joined pipe contact portion against the frame portion so that the predetermined value of frictional force is generated between the frame portion and the to-be-joined pipe contact portion; An attachment for connecting pipes on work machines.

6. The pipe connecting attachment for a work machine according to any one of claims 1 to 3; an arm to the tip of which the pipe joining attachment is attached; having Work machinery.

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