JP2022038221A - Truck frame of pile driver and pile driver - Google Patents

Abstract

To provide a truck frame which improves rigidity with respect to an operation load though the structure is simple and is suitable for usage of a pile driver, and the pile driver provided with the truck frame.SOLUTION: A truck frame of a pile driver incudes a cylindrical body 32 of which the center frame comes to an attachment seat of a revolving bearing 13 and back-and-forth and right-and-left leg part side plates 34 which are interposed between upper and lower plates 33, 38 and are extended so that an intermediate part constitutes a part of the cylindrical body. Therein, positions of upper and lower center combining parts 47, 48 which combine the cylindrical body, and the upper and lower central plate parts 33a, 38a are constituted such that the upper center combining part 47 is located on the upper side than a position of the upper end of a side frame 26 and the lower center combining part 48 is located on the lower side than a position of an axis (an axle) 46 of an idler wheel 24, respectively. Further, the lower plate 33 is constituted such that lower central plate part 33a, front leg part lower plate 33c and rear leg part lower plate are composed of a single plate material, and the whole region of the plate surface is flat.SELECTED DRAWING: Figure 14

Description

The present invention relates to a truck frame and a pile driver of a pile driver, and more particularly to a truck frame and a pile driver of a pile driver provided with a crawler as a traveling device.

In general, a hydraulic excavator as a typical example of a tracked vehicle includes a self-propelled lower traveling body equipped with a crawler (track), an upper turning body provided so as to be able to turn on the lower traveling body, and the upper portion. It is roughly composed of a work device provided on the front side of the swivel body so as to be movable up and down. The hydraulic excavator is used for excavating earth and sand using a working device while obtaining running stability on rough terrain with an upwardly convex truck frame that secures a minimum ground clearance (for example, Patent Document 1). reference.).

The track frame used for such hydraulic excavators has a crawler wound around them to ensure the maximum distance between the idle wheel at the front end and the drive wheel at the rear end, and its long ground contact length makes it excellent for running. Demonstrates sex and stability. In particular, small truck frames can be supplied at low cost by mass production, and are therefore widely used as general-purpose products in other construction machines such as pile drivers (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 10-236346 Japanese Unexamined Patent Publication No. 2011-252312

However, since the small pile driver described in Patent Document 2 described above is usually used in a place where the ground is leveled, a frame structure having a high ground clearance is essentially unnecessary, rather than running stability. I also want to focus on workability in a stationary state. Further, among various operations, when the pile is pulled out, a strong load acts on the track frame, and the load is maximized with the left and right idle wheels as fulcrums. When such a work load peculiar to a pile driver is applied, the left and right front legs of the truck frame are deformed in the elastic region, and the actual situation is that the pulling performance of the pile is deteriorated. In particular, in recent years, there has been an increasing need for higher output of work equipment even in small pile drivers, and there is a tendency to require even greater pulling force. Therefore, in such a general-purpose frame structure, small piles are used. There was a problem that the maximization of the pile driving function that the pile driver was aiming for could not be achieved.

Therefore, an object of the present invention is to provide a truck frame having a simple structure but having a high rigidity against a work load and suitable for a pile driver application, and a pile driver equipped with the track frame.

In order to achieve the above object, the track frame of the pile driving machine of the present invention has a center frame that rotatably supports the upper swivel body, and is located on both the left and right sides of the center frame and extends in the front-rear direction, and has a crawler on the outer periphery. Left and right side frames that connect the wound idle wheels and drive wheels, left and right front legs that connect between the front side of the center frame and the front sides of both side frames, and the rear side and both sides of the center frame. In the track frame of a pile driving machine consisting of left and right rear legs connecting to the rear side of the frame, the center frame has a cylindrical body to which a swivel bearing is attached and a lower center in which the cylindrical body is erected. A lower plate composed of a plate portion, left and right front leg lower plates extending from the lower central plate portion to form the lower surface of the front leg portion, and left and right rear leg lower plates constituting the lower surface of the rear leg portion, and the lower plate. From the left front leg lower plate standing on the front side of the leg front side plate extending in the left-right direction from the left front leg lower plate to the right front leg lower plate, and from the left rear leg lower plate standing on the rear side of the lower plate. The leg rear side plate extending in the left-right direction to the right rear leg lower plate is erected on the lower plate between the leg front side plate and the leg rear side plate, and the left rear leg is erected from the left front leg lower plate. A leg portion that is erected on the lower plate between the leg left side plate extending to the lower plate and the leg front side plate and the leg rear side plate and extends from the right front leg lower plate to the right rear leg lower plate. An insertion hole that is joined to the upper end side of the right side plate, the front side plate of the leg, the rear side plate of the leg, the left side plate of the leg, and the right side plate of the leg while facing the lower plate, and inserts the cylindrical body. From the upper central plate portion provided with, the left and right front leg upper plates extending from the upper central plate portion and forming the upper surface of the front leg portion, and the left and right rear leg upper plates forming the upper surface of the rear leg portion. The upper plate is provided, and the intermediate portion in the length direction of each side plate of the leg front side plate, the leg rear side plate, the leg left side plate, and the leg right side plate is the lower plate and the upper plate. A part of the cylindrical body is formed between them, and a connecting flange is fixed to the front side of the side frame, and a floating wheel bracket for supporting the shaft of the floating wheel is provided on the front surface of the connecting flange. The center frame is provided with upper and lower center joints for joining the cylindrical body to the upper center plate portion and the lower center plate portion, and the position of the upper center joint portion in the vertical direction is the side frame. It is positioned above the position of the upper end, and is characterized in that the position in the vertical direction of the lower center joint portion is located below the position of the shaft of the floating wheel supported by the floating wheel bracket.

Further, the lower plate is characterized in that the lower central plate portion, the front leg portion lower plate, and the rear leg portion lower plate are made of a single plate material, and the entire plate surface is flat. Further, the connection flange has a projecting portion that projects toward the center frame, and the front leg portion has a front end of each of the leg front side plate, the front leg upper plate, and the front leg lower plate of the projecting portion. It is characterized in that it is joined to the side frame in a state of being in contact with the rear surface.

In addition, the pile driving machine provided with the truck frame is provided with a holding device for holding the braked plate concentric with the turning center in the upper swivel body and the braked plate in the truck frame, respectively, of the holding device. The upper swing body can be fixed to an arbitrary position with respect to the track frame by operation, and a mounting bracket to which the holding device is attached is provided on a part of the cylindrical body so as to project in the radial direction. The bracket is characterized in that the positions of the upper and lower ends of the cross section perpendicular to the radial direction coincide with the upper surface of the upper center plate portion and the lower surface of the lower center plate portion, respectively.

According to the present invention, the center frame constituting the track frame of the pile driving machine is interposed between the cylindrical body serving as the mounting seat of the swivel bearing and the upper and lower plates, and the intermediate portion constitutes a part of the cylindrical body. The position of the upper and lower center joints that join the cylindrical body and the upper and lower center plates with the extended front, rear, left and right leg side plates, the upper center joint is above the position of the upper end of the side frame, and the lower center. Since the joints are positioned below the position of the shaft of the idler wheel, a center pipe structure is achieved that penetrates the cylinder concentric with the turning center of the upper swing body so as to reach the lower plate, and the pile is pulled out. The load, which is sometimes transmitted via the swivel bearing, can be appropriately distributed to the upper and lower plates with a frame cross section that is extended in the vertical direction by the length of the pipe. As a result, the rigidity and strength against bending in the vertical direction are greatly improved, and a track frame structure effective for the work load peculiar to the pile driver can be obtained.

It is a side view of the pile driver to which the truck frame which shows one embodiment of this invention is applied. It is also a side view of the lower traveling body with the swivel bearing attached. It is also a plan view. It is also a front view. It is also a side view of the track frame. It is also a plan view. FIG. 6 is a cross-sectional view taken along the line VII-VII of FIG. 6 is a cross-sectional view taken along the line VIII-VIII of FIG. It is also a side view of the center frame. It is also a plan view. 9 is a cross-sectional view taken along the line XI-XI of FIG. It is also a front view. FIG. 10 is a cross-sectional view taken along the line XIII-XIII of FIG. It is a figure explaining the force acting on the front side of a track frame. It is a cross-sectional view of XV-XV of FIG.

1 to 15 show an example of a form in which the present invention is applied to a pile driver. As shown in FIG. 1, the pile driver 11 is provided with an upper swivel body 14 rotatably provided on an upper portion of a self-propellable lower traveling body 12 via a swivel bearing 13, and is in front of the upper swivel body 14. In the center of the portion, a work device for pile driving such as a leader 15 and an auger (rotary drive device) 16 that moves up and down along the front surface of the leader 15 is provided. Further, on the main frame 14a of the upper swing body 14, an driver's cab 17 is provided on the right side portion, and an engine chamber 18 containing an engine and a hydraulic pump is provided on the left side portion. Further, jacks 19 are provided at four locations on the front, rear, left and right sides of the upper swivel body 14, and counterweights 20 for balancing the vehicle body are mounted on the rear end portions of the upper swivel body 14.

As shown in FIGS. 2 to 4, the lower traveling body 12 includes crawler-type traveling devices on both the left and right sides of the track frame 21. The lower traveling body 12 is a portion in contact with the ground, and is preferably formed long in the front-rear direction and wide in the left-right direction (vehicle width direction) so as to stably support the vehicle body. However, if the width of the vehicle is too wide, it may protrude from the trailer's loading platform during transportation, so it is not just a matter of widening it. From this point of view, the pile driver 11 to which the present invention is applied is a track frame having a size that can be easily loaded on a transport carrier without disassembling, for example, a tread (distance between the left and right crawler centers) of about 2 m. It is a relatively small pile driver using 21.

The track frame 21 is a can-making component that is a base of the lower traveling body 12, and is located on both the left and right sides of the center frame 22 and extends in the front-rear direction. The left and right side frames 26, 26 connecting the wheels 25, the left and right front legs 27, 27 connecting between the front side of the center frame 22 and the front sides of both side frames 26, 26, and the rear side of the center frame 22. It is roughly composed of left and right rear leg portions 28, 28 connecting between the side frames 26, 26 and the rear side thereof.

The swivel bearing 13 arranged between the lower traveling body 12 and the upper swivel body 14 has an inner case 13a on the inner ring side bolted to a mounting seat at the center of the track frame 21 and a center of the main frame 14a of the upper swivel body 14. The outer case 13b on the outer ring side, which is bolted to the lower surface, is assembled so as to be relatively rotatable. Further, an internal gear is formed on the inner circumference of the inner case 13a, and the gear of the swivel drive motor (not shown) mounted on the upper swivel body 14 is meshed with the internal gear, and the upper part is rotated by the rotation of the swivel drive motor. The swivel body 14 swivels in the horizontal direction with respect to the lower traveling body 12.

When the pile driver 11 is used for the purpose of burying a steel pipe pile, the steel pipe pile is rotationally press-fitted into the ground by obtaining a driving force from the auger 16 in a pile driving work posture in which the leader 15 is erected. In such pile driving work, a combined load of axial (vertical) compression and twist is applied to the leader 15 by receiving the propulsive force of the rotating pile, and as a result, a load exceeding the total load of the upper swivel body 14 is applied. Acts on the track frame 21 via the swivel bearing 13. In particular, when pulling out a pile, an extremely large pulling force is required due to the addition of earth pressure to the weight of the pile itself. Under these circumstances, the pile driver 11 is provided with a turning position fixing device 29 capable of fixing the upper turning body 14 at an arbitrary position in order to create a stationary stable state of the vehicle body.

The turning position fixing device 29 is composed of a braked plate 30 provided on the upper turning body 14 and concentric with the turning center, and a holding device 31 provided on the track frame 21 and holding the braked plate 30. There is. The brake plate 30 is formed in a ring shape by combining a pair of half-split members having the same shape, and is bolted to the lower surface of the outer case 13b of the swivel bearing 13.

The holding device 31 is provided so as to face two front and rear positions with the swivel bearing 13 interposed therebetween, and is supported by a base member 31a bolted to the wall portion of the track frame 21 and a rotating pin 31b to the base member 31a. It is composed of a pair of upper and lower chuck levers 31c and 31c in the shape of scissors and a chuck cylinder 31d that opens and closes both chuck levers 31c and 31c. When the chuck cylinder 31d is operated by hydraulic pressure, both tips of the chuck lever 31c are closed. The outer edge of the brake plate 30 is sandwiched.

Hereinafter, the specific structure of the track frame 21 will be described with reference to FIGS. 5 to 15. 5 to 8 show the completed state of the track frame 21, and FIGS. 9 to 13 show the component state (sub-assembly state) of the center frame 22. 14 and 15 show a state in which the crawler type traveling device and the turning position fixing device 29 are attached to the track frame 21.

The center frame 22 constituting the central portion of the track frame 21 is formed in a substantially X shape when viewed from above, and has a large-diameter cylindrical body 32 to which the swivel bearing 13 is attached and a lower center in which the cylindrical body 32 is erected. From the plate portion 33a, the left and right front leg lower plates 33b, 33c extending from the lower central plate portion 33a to form the lower surface of the front leg portion 27, and the left and right rear leg lower plates 33d, 33e forming the lower surface of the rear leg portion 28. On the lower plate 33, the leg front side plate 34 standing on the front side of the lower plate 33 and extending in the left-right direction from the left front leg lower plate 33b to the right front leg lower plate 33c, and the rear side of the lower plate 33. Standing on the lower plate 33 between the leg rear side plate 35 that is erected and extends in the left-right direction from the left rear leg lower plate 33d to the right rear leg lower plate 33e, and the leg front side plate 34 and the leg rear side plate 35. The left front leg 36 that extends from the lower left front leg plate 33b to the lower left rear leg 33d, and the right front leg that is erected on the lower plate 33 between the front leg plate 34 and the rear leg plate 35. The leg right side plate 37 extending from the lower plate 33c to the right rear leg lower plate 33e, the leg front side plate 34, the leg rear side plate 35, the leg left side plate 36, and the leg right side plate facing the lower plate 33. On the left and right front leg portions that are joined to the upper end side of the 37 and are provided with an insertion hole 38f through which the cylindrical body 32 is inserted and that extend from the upper central plate portion 38a and form the upper surface of the front leg portion 27. It is provided with an upper plate 38 composed of left and right rear leg upper plates 38d and 38e constituting the upper surfaces of the plates 38b and 38c and the rear leg 28.

In the lower plate 33, the lower center plate portion 33a, the front leg portion lower plates 33b, 33c, and the rear leg portion lower plates 33d, 33e are made of one steel plate material, and the entire plate surface is formed to be flat, and the front leg portion lower plate 33b is formed. , 33c and the rear leg lower plates 33d and 33e extend from the lower central plate 33a toward the inner side surface of the side frame 26, respectively. Further, the lower central plate portion 33a is provided with a central hole 33f having a diameter slightly smaller than the diameter of the cylindrical body 32 erected on the lower central plate portion 33a. In the upper plate 38, the upper center plate portion 38a, the front leg portion upper plates 38b, 38c, and the rear leg portion upper plates 38d, 38e are made of one steel plate material, and the front leg portion upper plate 38b is formed by bending the steel plate material. , 38c and the rear leg upper plates 38d and 38e extend downward from the upper center plate 38a toward the upper end of the side frame 26, respectively.

The cylindrical body 32 has a uniform cross-sectional shape over the entire length, is formed thicker than other parts to increase strength, and has a base ring (mounting seat) for mounting the swivel bearing 13 at the upper end. ) 32a is provided. Further, the intermediate portion in the length direction of each side plate of the leg front side plate 34, the leg rear side plate 35, the leg left side plate 36, and the leg right side plate 37 is a cylindrical body between the lower plate 33 and the upper plate 38. It constitutes a part of 32. Specifically, the cylindrical body is formed by eight connecting plates 34a, 34b, 35a, 35b, 36a, 36b, 37a, 37b arranged so as to interpose the peripheral wall portions P at four front, rear, left and right positions of the cylindrical body 32. A support structure integrated with 32 is formed.

Further, mounting brackets 39 to which the holding device 31 of the turning position fixing device 29 is attached are provided on the peripheral wall portions P at two front and rear positions, which are a part of the cylindrical body 32, so as to project in the radial direction (front-back direction). The mounting bracket 39 is mainly interposed between the mounting flange 39a to which the base member 31a of the holding device 31 is bolted and between the mounting flange 39a and the cylindrical body 32, and the upper and lower ends are the upper center plate portion 38a and the lower center. It has a pair of left and right standing plates 39b and 39b fixed to one side end of the plate portion 33a, respectively. As a result, the positions of the upper and lower ends of the cross section perpendicular to the radial direction of the cylindrical body 32 coincide with the upper surface of the upper center plate portion 38a and the lower surface of the lower center plate portion 33a, respectively, and are left and right with the upper and lower center plate portions 33a and 38a. A rectangular cross section (a U-shaped cross section on the tip side) composed of the standing plates 39b and 39b is formed. In this way, a bracket structure having increased strength with respect to the load in the circumferential direction of the cylindrical body 32, that is, the load in the turning direction of the upper swivel body 14 is formed.

As shown in FIGS. 5 to 8, the side frame 26 constituting the left and right side portions of the track frame 21 includes a side frame main body 40 located at the center in the front-rear direction (length direction) and the side frame main body 40. It is roughly composed of a floating wheel bracket 42 provided at the front end portion via a connecting flange 41 and a drive wheel bracket 44 provided at the rear end portion of the side frame main body 40 via another connecting flange 43.

In the side frame main body 40, the front leg portion 27 of the center frame 22 is connected to the front side and the rear leg portion 28 is connected to the rear side, and the front leg portion lower plates 33b and 33c and the rear leg portion lower plates 33d and 33e are joined. The front and rear sides have an inverted U-shaped cross section with the lower end side open by the face plate 40a, the outer surface plate 40b facing the inner surface plate 40a in the left-right direction, and the upper surface plate 40c connecting the upper ends of both inner and outer surface plates 40a and 40b. It extends in the direction.

The idler wheel bracket 42 includes left and right side plates 42a and 42a extending forward from the front surface of the connection flange 41, and left and right upper bending plates 42b extending inward from the side plates 42a and 42a to the idler wheel 24 side. It is formed as a substantially U-shaped frame body composed of 42b, lower bending plates 42c and 42c, and a reinforcing plate 42d in which the base end sides of the upper bending plates 42b and 42b are integrally connected to each other. On the surface of the frame body facing the floating wheel 24, vertical and horizontal guide frames 42e and 42f extending in the front-rear direction with a substantially L-shaped cross section are provided. Further, as shown in FIG. 14, a pair of left and right bearings 45, 45 attached to the tip side of a yoke (not shown) can move in the front-rear direction in the gap provided between the guide frames 42e and 42f. Both ends of the shaft (axle) 46 of the idler wheel 24 are supported by bearings 45 and 45.

In this way, the idle wheel 24 is attached to the idle wheel bracket 42, and the drive wheel 25 equipped with the hydraulic motor with a speed reducer is attached to the drive wheel bracket 44, and the idle wheel 24 and the drive wheel are driven by the rotary drive drive wheel 25. The crawler 23 wound around the 25 operates in a circular manner. Further, a tension adjusting device (not shown) to which the yoke is connected is provided between the floating wheel 24 and the side frame main body 40, and the crawler 23 is deformed due to undulations of the road surface or the like while the pile driver 11 is running. Even in this case, the tension adjusting device is activated to change the distance between the idle wheel 24 and the driving wheel 25, whereby the tension of the crawler 23 is adjusted.

In the track frame 21 of the pile driver 11 formed in this way, when the pile is pulled out among various auger operations, a strong load acts on the swivel bearing 13 and the load is applied to the left and right idle wheels 24. , 24 is the fulcrum and becomes the maximum. Such a work load peculiar to a pile driver causes deformation of a curved shape in a portion between the left and right front legs 27, 27 of the truck frame 21, and causes a factor of lowering the pulling performance of the pile. Therefore, the track frame 21 is provided with a frame joining structure for reducing the adverse effect of the work load.

In the frame joining structure, the center frame 22 and the left and right side frames 26, 26 are simultaneously formed while forming a frame cross section having a height that can withstand a bending load in the vertical direction with respect to the front leg portion 27 and the rear leg portion 28. It is a welded structure that can smoothly transmit the load between them, and has an upper and lower center joint for joining the cylindrical body 32 to the upper center plate portion 38a and the lower center plate portion 33a, and the front leg portion 27 and the rear. It is provided with front, rear, left and right side joints for joining the legs 28 to the left and right side frames 26, respectively.

As shown in FIGS. 13 and 13, the upper and lower center joints 47 and 48 are joined to be made of a difference thickness steel plate in which the thickness of the cylindrical body 32 is larger than the thickness of the upper center plate 38a and the lower center plate 33a. It is a part, whereby a desired swivel support function is exhibited. Speaking from the order of construction, first, with the cylinder (material) 32 fixed in the center of the upper surface of the lower center plate 33a, the cylinder 32 and the lower center plate 33a are firmly joined to each other by full-circumferential fillet welding. The lower center joint 48 is formed. Next, the eight connecting plates 34a, 34b, 35a, 35b, 36a, 36b, 37a, which constitute each side plate of the leg front side plate 34, the leg rear side plate 35, the leg left side plate 36, and the leg right side plate 37, The 37b and the constituent members of the mounting bracket 39 are temporarily assembled (temporarily welded) by abutting against the peripheral wall of the cylindrical body 32, respectively. After that, with the upper plate 38 and the lower plate 33 facing each other, in other words, the cylindrical body 32 is inserted into the insertion hole 38f of the upper center plate portion 38a, and the lower surface of the upper plate 38 is formed on each leg side plate 34, The main welding of the box structure is performed in a state of being in contact with the upper ends of the 35, 36, and 37. At this time, the upper center joint portion 47 is formed in which the cylindrical body 32 and the upper center plate portion 38a are firmly joined to each other by full peripheral fillet welding.

Further, the upper and lower center joints 47 and 48 are positioned so that the upper center joint 47 is located near the swivel bearing 13 and the lower center joint 48 is located near the ground so as not to interfere with running. The board structure of each part is taken. Specifically, the upper center joint portion 47 is located immediately below the support portion including the base ring 32a. When this is compared with the side frame main body 40, it is located above the top (upper end) of the top plate 40c. On the other hand, the lower center joint portion 48 is located at a height corresponding to the lower half portion of the inner surface plate 40a of the side frame main body 40. When this is compared with the floating wheel bracket 42, it is located at the same height as the lower guide frame 42f. That is, the lower center joint portion 48 is positioned below the position of the shaft 46 of the idler wheel 24 supported by the idler wheel bracket 42 in the completed state of the pile driver 11 (FIG. 14).

The front, rear, left and right side joints 49 and 50 are joints between the front and rear legs 27 and 28 of the center frame 22 and the left and right side frames 26, as shown in FIGS. 6 and 7, and in particular, the front and rear side joints 49 and 50. At the front and rear ends of the side frame main body 40, the front leg portion 27 is attached to the free wheel bracket 42 and the rear leg portion 28 is attached via the connection flanges 41 and 43 having the protrusions 41a and 43a protruding toward the center frame 22. It is a joint portion including a welded structure configured to be connected to each of the drive wheel brackets 44.

The front and rear protrusions 41a and 43a have a length (width) of reaching a substantially X-shaped virtual vertical plane S extending linearly from the turning center to the center (reaction point) of the idler wheel 24 and the drive wheel 25. The upper end thereof extends toward the center frame 22 along the bending (inclination) of the front leg upper plates 38b, 38c and the rear leg upper plates 38d, 38e. Further, the front and rear leg side plates 34, 35 (34a, 34b, 35a, 35b) extend from the peripheral wall of the cylindrical body 32 to the side frame 26 so as to diagonally cross the virtual vertical plane S, and the tip portion thereof is virtually vertical again. A gentle bend (with a large curvature) is performed in the direction intersecting the plane S, that is, in the direction facing the plate surfaces of the projecting portions 41a and 43a (front-back direction). Further, the left and right leg side plates 36, 37 (36a, 36b, 37a, 37b) extend from the peripheral wall of the cylindrical body 32 to the side frame 26 substantially parallel to the virtual vertical plane S, and the tip portion thereof is connected to the turning center. It is bent in the direction facing the inner surface plate 40a of the side frame main body 40 (left-right direction) at a position that divides the distance between 41 and 43 in the front-rear direction into two equal parts. In this way, in the center frame 22 in which the front and rear leg side plates 34, 35 (34a, 34b, 35a, 35b) are bent, the members joined to the side frame 26 are butted against each other in a T-shape.

When joining the center frame 22 and the left and right side frames 26, for the front leg portion 27, the front side top of the side frame main body 40 is the side end of the front leg portion upper plates 38b and 38c, and the inner side surface is the front leg portion lower plate 33b and 33c. , The front ends of the leg front side plates 34 (34a, 34b), the front leg upper plates 38b, 38c, and the front leg lower plates 33b, 33c, respectively, in contact with the side ends of the leg side plates 36, 37 (36a, 37a). It is assumed that the connecting flange 41 is in contact with the rear surface of the protruding portion 41a. On the other hand, regarding the rear leg portion 28, the rear side top of the side frame main body 40 is on the side end of the rear leg portion upper plates 38d and 38e, and the inner side surface is the rear leg portion lower plate 33d and 33e and the leg portion side plates 36 and 37 (36b). , 37b), respectively, and the rear ends of the leg rear side plates 35 (35a, 35b), the rear leg upper plates 38d, 38e, and the rear leg lower plates 33d, 33e are connected to the protruding portions of the flange 43. It is in a state of being in contact with the front surface of 43a. In this way, the side joints 49 and 50 are formed in which the front and rear legs 27 and 28 and the side frames 26 are firmly joined to each other by fillet welding in a temporarily assembled state in which the entire region of the center frame 22 is closed.

When pulling out the pile using the track frame 21 of the pile driver 11 formed in this way, as shown in FIG. 15, the pinching device 31 is operated in advance to fix the turning position of the upper swing body 14. .. Since such a static stable state of the pile driver 11 is created at an arbitrary turning position, for example, at a turning 0 ° position where the drive shaft of the auger 16 is positioned at the center between the widths of the left and right crawlers 23, 23, the pile is piled up. When the pulling force is received, a compressive load acts on the front side of the swivel bearing 13 in the direction indicated by the arrow F in FIG. On the other hand, the floating wheel bracket 42 receives a reaction force from the floating wheel 24, and a force acts in a direction of pushing up the guide frames 42e and 42e on both sides. Here, for example, at the position of turning right 90 °, a moment is applied in the direction indicated by the arrow M in FIG. 14, pushing up the guide frames 42e and 42f on one side of the idler wheel bracket 42 and pushing up the guide frames 42e on the other side. , 42f is pushed down, that is, the forces in the directions of the arrows M1 and M2 act.

Here, from the viewpoint of rigidity and strength, the problem that the idler wheel bracket 42 is twisted on the front surface of the connection flange 41 does not substantially occur, but the front leg portion 27 is the center frame 22 and the side frame 26. Since the structure is horizontally extended between the spaces, a bending load is applied to the structure, and the bending is likely to occur. However, the upper and lower center joints 47 and 48, which are spaced apart from each other, and the side joints 49, which correspondingly widen the area in the vertical direction, form a box structure with an increased cross section against the vertical bending direction. Therefore, the portion between the left and right front legs 27, 27 can withstand the transmitted load with almost no deformation.

In this way, the center frame 22 constituting the track frame 21 of the pile driving machine 11 is interposed between the cylindrical body 32 serving as the mounting seat of the swivel bearing 13 and the upper and lower plates 33 and 38, and the intermediate portion is the cylindrical body 32. The positions of the upper and lower center joints 47 and 48 that join the cylindrical body 32 and the upper and lower central plate portions 33a and 38a are provided with the front, rear, left and right leg side plates 34 and 35 extending to form a part of the above. Since the center joint 47 is located above the position of the upper end of the side frame 26 and the lower center joint 48 is located below the position of the shaft 46 of the idler wheel 24, it is concentric with the turning center of the upper swivel body 14. A center pipe structure is achieved that penetrates the cylindrical body 32 so as to reach the lower plate 33, and the load transmitted through the swivel bearing 13 when the pile is pulled out is expanded in the vertical direction by the length of the pipe. Can be appropriately dispersed in the upper and lower plates 33 and 38. As a result, the rigidity and strength against bending in the vertical direction are greatly improved, and the structure of the track frame 21 effective for the work load peculiar to the pile driver can be obtained.

Further, in combination with the simple center pipe structure, the lower plate 33, which is a part of the track frame 21, separately forms each part of the lower center plate portion 33a, the front leg portion lower plates 33b, 33c, and the rear leg portion lower plates 33d, 33e. It is made of a single plate, which makes the entire surface of the plate flat, which not only provides a frame structure that is inexpensive and has excellent manufacturability, but also has excellent weldability, so it can be mass-produced. The track frame 21 of a suitable pile driver 11 is achieved.

Further, the connecting flange 41 has a protruding portion 41a protruding toward the center frame 22, and the front leg portion 27 has a front end of each of the leg front side plate 34, the front leg upper plate 38b, 38c, and the front leg lower plate 33b, 33c. Since it is joined to the side frame 26 in a state of being in contact with the rear surface of the protruding portion 41a, the load is smoothly transmitted between the front leg portion 27 and the side frame 26, which greatly contributes to the load reduction of the front leg portion 27. It is something to do. In particular, since the leg front side plate 34 is arranged in association with the virtual vertical plane S extending from the turning center to the center of the idler wheel 24, the tip portion is gently bent in the direction facing the plate surface of the protruding portion 41a. The joint between the leg front side plate 34 and the connection flange 41 can be firmly joined with the butt T joint structure while obtaining the excellent support function of the X-shaped frame.

In addition, a mounting bracket 39 to which the holding device 31 of the swivel position fixing device 29 is attached is provided on a part of the cylindrical body 32 forming the center pipe structure so as to project radially, and the mounting bracket 39 has a cross section perpendicular to the radial direction. Since the positions of the upper and lower ends coincide with the upper surface of the upper center plate 38a and the lower surface of the lower center plate 33a, a bracket structure utilizing a part of the track frame 21 is used during pile pulling work. It is possible to exhibit high static stability, which contributes to maximizing the pile driving function aimed at by the small pile driver 11.

The present invention is not limited to the above embodiment, and the cylindrical body serving as the mounting seat for the swivel bearing may be formed so as to extend from the upper plate to the lower plate of the track frame and connect to the legs. Manufacturing changes such as member removal and processing can be made as appropriate. In addition, lowering the position of the lower center joint contributes to improving the rigidity and strength of the entire truck frame, but if it is further lowered to the extent that it does not interfere with running or transportation, the position of the lower plate will be adjusted accordingly. There is an advantage that the center of gravity of the car body can be further lowered. Further, the lower plate is not limited to a flat shape, and various modes such as bending the lower plate of the leg can be considered.

11 ... pile driving machine, 12 ... lower traveling body, 13 ... swivel bearing, 13a ... inner case, 13b ... outer case, 14 ... upper swivel body, 14a ... main frame, 15 ... leader, 16 ... auger, 17 ... driver's cab , 18 ... engine room, 19 ... jack, 20 ... counter weight, 21 ... track frame, 22 ... center frame, 23 ... crawler, 24 ... idle wheel, 25 ... drive wheel, 26 ... side frame, 27 ... front leg, 28. ... rear leg, 29 ... swivel position fixing device, 30 ... braked plate, 31 ... holding device, 31a ... base member, 31b ... rotating pin, 31c ... chuck lever, 31d ... chuck cylinder, 32 ... cylindrical body, 32a ... Base ring, 33 ... Lower plate, 33a ... Lower center plate, 33b, 33c ... Front leg lower plate, 33d, 33e ... Rear leg lower plate, 33f ... Center hole, 34 ... Leg front side plate, 34a, 34b ... Connected Plate, 35 ... Leg rear side plate, 35a, 35b ... Connecting plate, 36 ... Leg left side plate, 36a, 36b ... Connecting plate, 37 ... Leg right side plate, 37a, 37b ... Connecting plate, 38 ... Upper plate, 38a ... Upper center plate, 38b, 38c ... Front leg upper plate, 38d, 38e ... Rear leg upper plate, 38f ... Insertion hole, 39 ... Mounting bracket, 39a ... Mounting flange, 39b ... Stand plate, 40 ... Side frame body , 40a ... inner surface plate, 40b ... outer surface plate, 40c ... top plate, 41 ... connection flange, 41a ... protrusion, 42 ... idle wheel bracket, 42a ... side plate, 42b ... upper bending plate, 42c ... lower bending plate, 42d ... Reinforcing plate, 42e, 42f ... Guide frame, 43 ... Connection flange, 43a ... Projection, 44 ... Drive wheel bracket, 45 ... Bearing, 46 ... Shaft, 47, 48 ... Center joint, 49, 50 ... Side joint

Claims (4)

A center frame that supports the upper swivel body so that it can swivel, and left and right side frames that are located on both the left and right sides of the center frame and extend in the front-rear direction to connect a floating wheel and a drive wheel around which a crawler is wound. It consists of left and right front legs that connect the front side of the center frame and the front sides of both side frames, and left and right rear leg portions that connect the rear side of the center frame and the rear sides of both side frames. In the truck frame of a pile driver
The center frame is
A cylinder to which a swivel bearing is attached, and
The lower center plate on which the cylinder is erected, the left and right front leg lower plates extending from the lower center plate to form the lower surface of the front leg, and the left and right rear leg lower plates forming the lower surface of the rear leg. The lower plate consisting of
A leg front side plate that is erected on the front side of the lower plate and extends in the left-right direction from the left front leg lower plate to the right front leg lower plate.
A leg rear side plate that is erected on the rear side of the lower plate and extends in the left-right direction from the left rear leg lower plate to the right rear leg lower plate.
A leg left plate that stands on the lower plate between the leg front plate and the leg rear plate and extends from the left front leg lower plate to the left rear leg lower plate.
A leg right side plate that stands on the lower plate between the leg front side plate and the leg rear side plate and extends from the right front leg lower plate to the right rear leg lower plate.
It is joined to the upper end side of the leg front side plate, the leg rear side plate, the leg left side plate, and the leg right side plate while facing the lower plate, and an insertion hole for inserting the cylindrical body is provided. An upper plate composed of an upper central plate portion, left and right front leg upper plates extending from the upper central plate portion to form the upper surface of the front leg portion, and left and right rear leg upper plates extending from the upper central plate portion to form the upper surface of the rear leg portion. Equipped with
The middle portion in the length direction of each side plate of the leg front side plate, the leg rear side plate, the leg left side plate, and the leg right side plate is one of the cylindrical bodies between the lower plate and the upper plate. It consists of a part
A connecting flange is fixed to the front side of the side frame, and a floating wheel bracket for supporting the shaft of the floating wheel is provided on the front surface of the connecting flange.
The center frame includes upper and lower center joints for joining the cylindrical body to the upper center plate portion and the lower center plate portion, and the vertical position of the upper center joint portion is the upper end of the side frame. The pile driving machine is located above the position, and the vertical position of the lower center joint is located below the position of the shaft of the floating wheel supported by the floating wheel bracket. Track frame. The pile according to claim 1, wherein the lower central plate portion, the front leg portion lower plate, and the rear leg portion lower plate are made of a single plate material, and the entire plate surface is flat. Pile driver truck frame. The connection flange has a projecting portion that projects toward the center frame, and the front leg portion has the front ends of the leg front side plate, the front leg upper plate, and the front leg lower plate on the rear surface of the projecting portion. The truck frame of a pile driver according to claim 1 or 2, wherein the truck frame is joined to the side frame in an abutting state. A pile driver provided with the truck frame according to any one of claims 1 to 3, wherein the upper swivel body has a brake plate concentric with the turning center, and the truck frame sandwiches the brake plate. Each of the holding devices is provided, and the upper swing body can be fixed at an arbitrary position with respect to the track frame by operating the holding device.
A mounting bracket to which the pinching device is attached is provided on a part of the cylindrical body so as to project in the radial direction. A pile driver characterized in that the upper surface and the lower surface of the lower center plate portion coincide with each other.

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