JP4595050B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle traveling by a crawler belt.

A sprocket is provided at one end of the traveling frame so that it can be driven for rotation, and an idler is provided at the other end of the traveling frame so as to be movable in the front-rear direction and is rotatable. In the vehicle in which the tension is applied to the crawler belt by urging the crawler belt through the cylinder device, the reverse drive pressure of the traveling hydraulic motor that drives the sprocket is increased by the pressure booster and output to the cylinder device. Thus, there is known one that increases the crawler belt tension during reverse travel (see, for example, Patent Document 1).
JP 58-53576 A (page 3, FIG. 4)

  As shown in Patent Document 1, when installing a pressure-increasing device for adjusting the crawler belt tension separately from the cylinder device, it is necessary to change the traveling frame in order to secure an installation space for the pressure-increasing device.

  In addition, depending on the size of the intensifier, etc., it is necessary to provide a sufficiently large access hole for attachment work in the traveling frame, but it is difficult to open such an access hole due to the strength and space of the traveling frame. It is.

  Furthermore, it is necessary to perform piping work between the cylinder device and the pressure intensifier, and there is a problem that workability is lowered.

  The present invention has been made in view of the above points, and provides a vehicle having a crawler belt tension applying cylinder device in which a pressure intensifier for adjusting the crawler belt tension is incorporated so compactly that it is not necessary to change the frame structure. It is for the purpose.

The present invention includes a main body frame, a track frame provided on each of the left and right sides of the main body frame, a sprocket provided at one end of each track frame so as to be rotationally driven, and a front-rear direction at the other end of each track frame. A movable and rotatable idler, an endless crawler belt wound around each sprocket and each idler, and each idler installed in the track frame in the projecting direction by compressive fluid pressure A cylinder device that biases and applies tension to each crawler track, the cylinder device having a cylinder body and a piston integrated with a rod that is slidably fitted into the cylinder body and protrudes from the cylinder body; Compressibility filled with compressible fluid formed on the head side opposite to the rod side from the piston in the cylinder body The body chamber, the incompressible fluid chamber defined on the rod side from the piston in the cylinder body, and the incompressible fluid pressure that is integrally provided at the rod side end of the cylinder body and increased from the input pressure are incompressible. And a pressure intensifier that outputs to the compressive fluid chamber. The idler is urged in the extending direction by the compressive fluid pressure to apply tension to each crawler belt, and the crawler belt by the incompressible fluid pressure increased by the intensifier. a vehicle for adjusting the tension, pressure intensifier in a vehicle of this is, the intensifier body disposed annular with a gap around the rod of the integrated cylinder device the cylinder body of the cylinder device, the intensifier body vehicle incompressible fluid pressure that has been increased from axially slidably fitted input pressure receiving input pressure comprises an annular booster piston to be output to the incompressible fluid chamber of the cylinder device within It is .

According to the present invention, since the compressible fluid chamber filled with compressible fluid is formed on the head side from the piston in the cylinder body, the idler is urged in the protruding direction by the compressive fluid pressure, and each crawler belt is tensioned. And an incompressible fluid chamber is defined on the rod side of the piston in the cylinder body, and the increased incompressible fluid pressure is output to the rod side end of the cylinder body to the incompressible fluid chamber. Since the intensifier for adjusting the crawler belt tension is integrated, the intensifier can be made compact, preventing structural changes such as the main body frame and the track frame, and a large access hole for mounting work on the main body frame and the track frame. Since it is not necessary to provide a sufficient frame strength, it is not necessary to perform piping work between the cylinder device and the pressure booster, improving workability. Kill. In particular, through the gap around the rod of the cylinder device, the intensifier body intensifier which is integrated in the cylinder body of the cylinder device is disposed in an annular, axially annular booster piston to the booster body Although the pressure intensifier fitted so as to be slidable is compactly configured with the rod as the center, the pressure intensifier does not receive a radial load from the rod or the like, and can provide a structure excellent in strength.

  The present invention will be described below with reference to one embodiment shown in FIGS.

  As shown in FIG. 3, a hydraulic excavator as a work machine has a crawler type vehicle 1 as a base machine, and the vehicle 1 is provided on a lower traveling body 2 and on the lower traveling body 2 so as to be able to turn. The upper swing body 3 is mounted with a cab 4, a front working device 5 for excavation, a power device 6 that drives a hydraulic pump by an engine, and the like.

  As shown in FIG. 1, the lower traveling body 2 is provided with a hollow turning column 12 for installing the upper turning body 3 at the center of the main body frame 11, and a track frame on both left and right sides of the main body frame 11. As shown in FIG. 3, a track drive sprocket 14 is provided at one end of each of the track frames 13 so as to be driven to rotate by a traveling hydraulic motor (not shown).

  On the other hand, an idler 16 is rotatably supported at the other end of each track frame 13 by a shaft support member 16a that can move in the front-rear direction along a guide member 13a integral with each track frame 13. An endless crawler belt 17 is wound around each idler 16.

  A track roller 18 that guides and supports the lower part of the crawler belt 17 between the sprocket 14 and the idler 16 and a carrier roller 19 that guides and supports the upper part of the crawler belt 17 are rotatably supported on each track frame 13. ing.

  Also, in each of the left and right track frames 13, a cylinder device that applies a tension to each crawler belt 17 by urging the shaft support member 16a of each idler 16 in an extending direction by an inert gas pressure as a compressible fluid pressure. 21 are installed. Each of these cylinder devices 21 has a buffering recoil cylinder function for elastically pressing the idler 16 in the extending direction and absorbing an impact applied to the crawler belt 17.

  As shown in FIG. 1, each cylinder device 21 is provided with a cylinder body 31 in which a shaft support member 16 a of an idler 16 is integrated along a guide rail 30 provided in a track frame 13 so as to be movable in the front-rear direction. In this cylinder body 31, a piston 32 is fitted in a hermetically slidable manner through a seal 34 fitted in a recessed groove 33 on the circumferential surface of the piston. A rod 35 protruding from 31 is integrally provided, and this rod 35 protrudes in the sprocket direction from one end of the cylinder body 31, and the rod tip 35a is a plate provided to partition the inside of the track frame 13. It is latched by the shaped latching member 36.

  An oil chamber 37 as an incompressible fluid chamber that receives supply of oil as an incompressible fluid from the piston 32 to the rod 35 side from the piston 32 is defined in the cylinder body 31. An air chamber 38 as a compressible fluid chamber functioning as an accumulator is defined in the opposite head side. The air chamber 38 applies tension to the crawler belt 17 by urging the idler 16 in the extending direction by an inert gas pressure.

As shown in FIG. 2, the air chamber 38 has an inert gas as a compressive fluid such as nitrogen gas N ₂ through an inert gas supply hole 39 formed in the rod 35 of the piston 32. Is filled. Since this inert gas is chemically stable, a highly stable accumulator function can be obtained. The inert gas supply hole 39 opens to the side surface of the rod at the tip of the rod 35, but is closed by a valve connected to the opening, a plug (both not shown), or the like. .

  Further, the cylinder device 21 includes a pressure intensifier 40 that is integrally provided at the rod side end of the cylinder body 31, and each of the oil pressures as incompressible fluid pressures increased from the input pressure by the pressure intensifier 40. Output to the oil chamber 37 of the cylinder device 21 to adjust the tension of the crawler belt 17.

  The intensifier 40 has a large-diameter chamber 42 and a small-diameter chamber 43 formed in the intensifier body 41, and the large-diameter portion 45 and the small-diameter portion 46 of the booster piston 44 are formed in the large-diameter chamber 42 and the small-diameter chamber 43, respectively. Each of the large-diameter chambers 42 is connected to a port 48 provided in an annular cap 47 that is integrally fitted to the intensifier body 41, and the small-diameter chamber 43 passes through a passage 49. Then, it communicates with the oil chamber 37. The small-diameter chamber 43 incorporates a return spring 50 that returns the pressure-increasing piston 44 to the position shown in FIGS.

  Thus, the pressure booster body 41 of the pressure booster 40 is fitted and integrated with the cylinder body 31 of the cylinder device 21, and is arranged around the rod 35 of the cylinder device 21 in an annular shape via the gap 51. An annular pressure-increasing piston 44 fitted in the pressure-intensifier body 41 so as to be slidable in the axial direction receives the input pressure from the port 48 in the large-diameter portion 45, and the oil pressure increased from the input pressure is reduced in the small-diameter portion. From 46, it passes through passage 49 and is output to oil chamber 37.

  This cylinder device 21 has a cushioning recoil cylinder that absorbs the impact applied to the crawler belt 17 while elastically pressing the shaft support member 16a of the idler 16 in the overhanging direction by the air chamber 38, similarly to the conventional recoil cylinder. As well as the conventional adjuster cylinder, it functions as an adjuster cylinder for tension adjustment that adjusts the tension of the crawler belt 17, by controlling the hydraulic pressure supplied to the oil chamber 37 by the pressure intensifier 40. is there.

  Next, the function and effect of this embodiment will be described.

  A unit obtained by integrating the pressure intensifier 40 integrally with the cylinder device 21 is stored in the space for the conventional spring system in the track frame 13 by the same assembling procedure.

  The function of the recoil cylinder for absorbing shock acting on the crawler belt 17 will be described. The inert gas pressure in the air chamber 38 tracks the cylinder body 31 against the piston 32 locked at a fixed position. When an external force is applied in the direction of pushing out from the frame 13 while pushing the shaft support member 16a into the track frame 13, the input pressure from the port 48 is received by the large-diameter portion 45. Since the increased hydraulic pressure is output from the small diameter portion 46 to the oil chamber 37 through the passage 49, the cylinder body 31 moves backward while compressing the inert gas filled in the air chamber 38, and as a recoil spring that absorbs external force Function.

  That is, the inert gas pressure in the air chamber 38 elastically pushes the shaft support member 16a of the idler 16 in the extending direction by utilizing the force that elastically pushes the cylinder body 31 against the piston 32, and the crawler belt Appropriate tension is applied to the track 17, but when the crawler belt 17 rides on rocks, etc. or bites in rocks, etc., and the impact is applied to the crawler belt 17, an excessive load is applied from the crawler belt 17 to the idler 16. The cylinder body 31 can move backward while compressing the inert gas in the air chamber 38 with respect to the piston 32 locked in position, and can absorb the impact applied to the crawler belt 17.

  Further, the function as an adjuster cylinder for adjusting the tension of the crawler belt 17 will be described. The signal pressure circuit connected to the port 48 of the intensifier 40 is supplied to the large-diameter chamber 42 in the intensifier body 41. By controlling the input pressure, a hydraulic pressure increased in inverse proportion to the diameter ratio between the large diameter portion 45 and the small diameter portion 46 of the pressure increasing piston 44 is generated in the small diameter chamber 43 and passes through the passage 49 to the oil chamber 37. Therefore, by adjusting the oil pressure of the oil chamber 37 by the pressure intensifier 40, the inert gas is determined by the relative relationship between the oil pressure in the oil chamber 37 and the inert gas pressure filled in the air chamber 38. The tension of the crawler belt 17 is adjusted by adjusting the force with which the pressure pushes the cylinder body 31.

  That is, when the hydraulic pressure supplied from the pressure intensifier 40 to the oil chamber 37 is increased, the force by which the inert gas pressure in the air chamber 38 tries to push the cylinder body 31 is reduced. When the oil pressure is lowered, the force with which the inert gas pressure in the air chamber 38 tries to push the cylinder body 31 increases.

  As described above, the function as a recoil cylinder for buffering and the function as an adjuster cylinder for tension adjustment are integrated into one cylinder device 21, so that the structure becomes simple and can be provided at low cost.

  Furthermore, since the cylinder device 21 with a built-in accumulator function is incorporated in the track frame 13 of the lower traveling body 2 that is easily accessible from the outside, maintenance such as gas charging can be facilitated.

  Further, an oil chamber 37 is defined on the rod side of the piston 32 in the cylinder body 31, and a pressure-increasing device 40 for adjusting the crawler belt tension is output to the oil chamber 37 at the rod side end of the cylinder body 31. Since the pressure intensifier 40 is compact, the structure of the main body frame 11 and the track frame 13 can be prevented from being changed.

  Furthermore, it is not necessary to provide a large pressure booster mounting access hole in the main body frame 11 or the track frame 13, etc., so that sufficient frame strength can be secured, and further, piping work between the cylinder device 21 and the pressure booster 40. Since it is not necessary to work, workability can be improved.

  Further, an intensifier body 41 integrated with the cylinder body 31 of the cylinder device 21 is arranged in an annular shape around the rod 35 of the cylinder device 21 via a gap 51, and the annular intensifier is placed in the intensifier body 41. The pressure booster 40 fitted with the piston 44 so as to be slidable in the axial direction does not receive an eccentric load in the radial direction from the rod 35 or the like, although it is compactly configured around the rod 35. Can provide an excellent structure.

1 is a cross-sectional view showing an embodiment of a vehicle according to the present invention. It is sectional drawing of the cylinder apparatus and pressure booster which were provided in the vehicle same as the above. It is a perspective view of the hydraulic excavator comprised with the vehicle same as the above.

1 vehicle
11 Body frame
13 Track frame
14 Sprocket
16 Idler
17 tracks
21 Cylinder device
31 Cylinder body
32 pistons
35 rod
37 Oil chamber as incompressible fluid chamber
38 Air chamber as a compressible fluid chamber
40 Booster
41 Booster body
44 Booster piston
51 gap

Claims (1)

Body frame,
Track frames provided on both the left and right sides of the main body frame,
A sprocket provided at one end of each track frame so as to be able to rotate,
An idler provided at the other end of each track frame so as to be movable in the front-rear direction and rotatably;
Endless crawler belts wound around each sprocket and each idler,
A cylinder device installed in a track frame and urging each idler in a protruding direction by compressive fluid pressure to apply tension to each crawler track,
The cylinder device
A cylinder body,
A piston integrated with a rod that is slidably fitted into the cylinder body and protrudes from the cylinder body;
A compressible fluid chamber that is partitioned on the head side opposite to the rod side from the piston in the cylinder body and is filled with a compressible fluid;
An incompressible fluid chamber defined on the rod side of the piston in the cylinder body;
A pressure intensifier integrally provided at the rod side end of the cylinder body and outputting the incompressible fluid pressure increased from the input pressure to the incompressible fluid chamber;
The vehicle adjusts the crawler belt tension with the incompressible fluid pressure increased by the incompressible fluid pressure while urging the idler in the extending direction by compressive fluid pressure to apply tension to each crawler track,
The intensifier is
A pressure intensifier body integrated with the cylinder body of the cylinder device and arranged annularly around the rod of the cylinder device via a gap;
An annular pressure-increasing piston that is slidably fitted in the pressure intensifier body and receives the input pressure and outputs the incompressible fluid pressure increased from the input pressure to the incompressible fluid chamber of the cylinder device. car shall be the feature that it has provided both.

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