JP2009220690A - Mount structure of drive axle for industrial vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mount structure of a drive axle for an industrial vehicle suitable for improving maintenance workability. <P>SOLUTION: The drive axle 1 for the industrial vehicle is composed of an axle housing 2 including a final reduction gear 4 and a differential gear 5; and an axle tube 3 including at least one of a wet oiling brake mechanism 6 and a planetary gear mechanism 7, rotatably supporting an axle hub 24 supporting driving wheels W on an outer periphery on a tip end side, and fixed and disposed at both ends of the axle housing 2 through mounting bolts 3B as fastening means. A pair of brackets 50 fixed and disposed at both ends of the axle housing 2 with mounting bolts 55 as first fastening means or integrally formed at both ends of the axle housing 2 is fastened and fixed at a front part of a vehicle frame 12 with mounting bolts 56 as second fastening means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mounting structure for an industrial vehicle drive axle, and more particularly to a mounting structure for an industrial vehicle drive axle suitable for incorporating a device such as a wet brake that requires disassembly and maintenance in the drive axle.

  2. Description of the Related Art Conventionally, a drive axle for an industrial vehicle in which a wet brake that requires disassembly and maintenance is built in the drive axle is known (see Patent Document 1).

This includes an axle housing that incorporates a final drive that decelerates the power input from the propeller shaft and a differential, and an axle tube that is coupled to both ends of the axle housing and supported by the vehicle body. At the outer ends of the left and right axle tubes, an axle hub to which drive wheels are coupled is rotatably supported. A housing space is formed in the connecting portion between the axle tube and the axle housing, and the planetary gear mechanism and the wet brake mechanism are built in.
JP 2000-297830 A

  However, in the above conventional example, the axle tube arranged on the left and right of the drive axle is fixed to the vehicle body. Therefore, when it is necessary to provide a built-in wet brake or planetary gear mechanism, the axle drive device It was necessary to remove the entire vehicle from the vehicle, and there was a problem that maintenance workability was complicated.

  Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide an industrial vehicle drive axle mounting structure suitable for improving maintenance workability.

  The present invention includes an axle housing that incorporates a final reduction gear and a differential, and at least one of a wet brake mechanism and a planetary gear mechanism, and an axle hub that supports a driving wheel on the outer periphery of the tip end. An axle tube fixed to both ends of the axle housing via fastening means, and an industrial vehicle drive axle, and fixed to the both ends of the axle housing by first fastening means, or A pair of brackets integrally formed at both end portions of the axle housing are fastened and fixed to the front portion of the vehicle body frame by the second fastening means.

  Therefore, according to the present invention, both end portions of the axle housing of the drive axle for an industrial vehicle in which at least one of the wet brake mechanism and the planetary gear mechanism is built in the axle tube fixedly disposed at both ends of the axle housing via the fastening means, respectively. Furthermore, the axle housing and the bracket are fastened and fixed by fastening a pair of brackets fixedly arranged by the first fastening means or integrally formed at both ends of the axle housing to the vehicle body frame. For this reason, in the state where the drive axle is attached to the vehicle body by the bracket, it is possible to remove the axle tube alone together with its built-in components by loosening the fastening means for the axle housing without removing the entire drive axle. The maintainability of the built-in wet brake mechanism and planetary gear mechanism can be improved.

  Hereinafter, an embodiment of a drive axle mounting structure for an industrial vehicle according to the present invention will be described with reference to FIGS. FIG. 1 is a system diagram of a drive mechanism in an industrial vehicle equipped with an industrial vehicle drive axle, and FIG. 2 is a cross-sectional view of the industrial vehicle drive axle including a mount structure. Here, first, a drive mechanism in an industrial vehicle will be described.

  In FIG. 1, the drive mechanism in the industrial vehicle of this embodiment is arranged on the axle housing 2 on the vehicle center side containing a final drive device (final reduction gear device) 4 and a differential device (differential device) 5, and on both sides thereof. In addition, the wet type brake mechanism 6 and the planetary gear mechanism 7 are built in, and the drive axle 1 including left and right axle tubes 3 that rotatably support the drive wheels W at both ends thereof is provided. The final drive device 4 of the drive axle 1 is configured to receive a driving force from the engine 11 via a torque converter 8, a transmission 9 having a forward / reverse switching function and a deceleration function, and a propeller shaft 10. . In an industrial vehicle represented by a forklift, the drive axle 1 and the drive wheel W are disposed on the front side of the vehicle, and the transmission 9 and the engine 10 are disposed on the rear side of the vehicle.

  As shown in FIG. 2, the industrial vehicle drive axle 1 of the present embodiment fixes an axle housing 2 containing a final drive device 4 and a differential device 5 to a vehicle body frame 12 (only a part is shown) by a bracket 50. The structure is such that the axle tube 3 is coupled to the flange 2A provided on both sides of the housing 2 via the flange 3A.

  The axle tube 3 includes a housing portion 20 whose diameter is increased so as to form a housing space in which the planetary gear mechanism 7 and the wet brake mechanism 6 are housed on the side coupled to the axle housing 2 via the flange 3A. Further, the diameter of the housing portion 20 is reduced to the side opposite to the axle housing 2, and the drive shaft 22 is built in and the axle hub 24 is rotatably supported by a hub bearing 23 including a pair of tapered roller bearings on the outer peripheral portion. A tube portion 21.

  The drive shaft 22 and the axle hub 24 are connected by bolts. A seal 25 is disposed between the axle tube 3 and the axle hub 24 so that the inside of the hub bearing 23 and the axle tube 3 is blocked from the outside. A wheel rim (not shown) of the wheel is fixed to the axle hub 24. The axle tube 3, the hub bearing 23, and the axle hub 24 constitute a fully floating axle structure, and only the torsional torque for driving the drive wheels W acts on the drive shaft 22. Further, since the vehicle load and the loaded load are transmitted from the vehicle body to the driving wheel W via the axle housing 2, the axle tube 3, the hub bearing 23, and the axle hub 24, the drive shaft 22 is subjected to bending loads due to these loads. It has a structure that does not.

  A carrier 26 of the planetary gear mechanism 7 is splined to an end portion of the axle shaft 3 of the drive shaft 22, and a plurality of pins 27 </ b> A that rotatably support the planetary gear 27 are fixed to the carrier 26. . A ring gear 28 that meshes with each planetary gear 27 from the outer periphery is disposed on the outer periphery of the plurality of planetary gears 27, and this ring gear 28 is fixed to the inner peripheral wall surface of the accommodating portion 20 of the axle tube 3 by spline fitting. . A sun gear 29 that meshes with each planet gear 27 from the inner periphery is disposed on the inner periphery of the plurality of planetary gears 27. The sun gear 29 is integrated with the input shaft 30 by spline fitting. The input shaft 30 is rotatably supported via a bearing 31A on a partition wall 31 fitted to an inner wall surface of a portion (open end portion) where an attachment flange 3A of the housing portion 20 of the axle tube 3 to the axle housing 2 is located. Supported. An output shaft 32 of the differential device 5 built in the axle housing 2 is connected to the end of the input shaft 30 by spline coupling. The carrier 26 is rotatably supported by a bearing 33 on a shoulder portion between the tube portion 21 and the accommodating portion 20 of the axle tube 3. Because of such a planetary gear mechanism 7, the torque input from the input shaft 30 to the sun gear 29 is increased in torque from the carrier 26 and output to the drive shaft 22. The drive shaft 22 transmits torque to the flange-coupled axle hub 24.

  The wet brake mechanism 6 includes a plurality of brake disks 34 whose inner peripheral portions are spline-fitted to splines provided on the input shaft 30. Further, the outer peripheral portion is spline-fitted to the inner peripheral wall of the accommodating portion 20 in the axle tube 3, and two thick end plates 35 (one fixed end fixed to the inner wall surface of the accommodating portion 20 space in the axle tube 3). The plate 35A and the other end are provided with a movable end plate 35B) that is movable in the approaching / separating direction with respect to the fixed end plate 35A and is non-rotatable. Between the two end plates 35A and 35B, a plurality of friction disks 36 are arranged so as to be axially movable but not rotatable. A plurality of friction disks 36 between the end plates 35A and 35B are alternately stacked in the axial direction with a plurality of brake disks 34. The axle tube 3 is rotatably provided with a shaft 37 therethrough, and a release lever 38 that is bifurcated across the input shaft 30 is integrally fixed to a portion of the shaft 37 positioned in the axle tube 3. . The movable end plate 35 </ b> B is arranged on the movement locus of the bifurcated tip of the release lever 38. A lever 39 is integrally fixed to the shaft 37 located outside the axle tube 3, and a piston rod of an operating cylinder 40 fixed to the outer periphery of the axle tube 3 is connected to the tip of the lever 39. . The operating cylinder 40 is configured to be supplied with hydraulic pressure from a master cylinder 42 (for service brake) that generates hydraulic pressure when the brake pedal 41 in the driver's seat is depressed.

  Therefore, when the brake pedal 41 is depressed, the brake fluid pressure generated by the master cylinder 42 is supplied to the operating cylinder 40 and the piston rod is extended to rotate the lever 39, the shaft 37 and the release lever 38, The end plate 35B is pressed by the bifurcated end of the release lever 38, the brake plate 34 fixed to the input shaft 30 is clamped by the friction plate 36 between the end plates 35A, 35B, and the wet brake mechanism 6 is braked. The input shaft 30 is braked. In addition, a parking brake cable 44 that pulls by operating the parking brake lever 43 in the driver's seat is connected to the end of the lever 39 of the shaft 37 that passes through the axle tube 3, and by operating the parking brake lever 43, The wet brake mechanism 6 can be operated. If it does in this way, the common wet brake mechanism 6 can be operated with a service parking brake, and a structure can be simplified.

  The industrial vehicle drive axle 1 described above is fixed to the vehicle body frame 12 by the mounting structure of the first embodiment shown in FIGS. That is, in the first embodiment, brackets 50 are attached to both ends of the axle housing 2 arranged on the vehicle center side, and each bracket 50 is attached to the body frame 12 (a pair of side members extending forward from both side surfaces). By attaching to the front end, it is fixed to the vehicle body frame 12 (side member). 3 is a plan view including the mounting structure of the drive axle 1 for an industrial vehicle, FIG. 4 is a front view including the mounting structure, FIG. 5 is a side view including the mounting structure, FIG. 6 is a perspective view including the mounting structure, and FIG. It is a perspective view from the vehicle rear containing a mount structure.

  The bracket 50 includes a ring body 51 that surrounds the end of the axle housing 2, a mast support portion 52 that is provided integrally with the ring body 51, and a plate that extends from the ring body 51 and extends along the upper surface of the axle housing 2. A body 53 and a flange body 54 connected to a portion facing the position of the mast support portion 52 of the ring body 51 are configured.

  As shown in FIG. 4, the plate body 53 of the bracket 50 is formed in a planar shape along the upper surface of the axle housing 2, and the end surface of the boss 2B protruding from the upper surface of the axle housing 2 contacts the lower surface from below. Then, the plurality of mounting bolts 55 are screwed into the boss 2B of the axle housing 2 through the mounting holes provided in the plate body 53, thereby being fixed to the axle housing 2. As shown in FIGS. 5 to 7, the bracket 50 fixed to the axle housing 2 is arranged so that a ring body 51 surrounds an end region of the axle housing 2, and extends from the ring body 51 to the rear of the vehicle to form a flange body. 54 and a mast support portion 52 at the front lower part of the vehicle.

  As shown in FIGS. 3, 5, and 7, the bracket 50 fixed to the axle housing 2 includes a mounting surface on the vehicle lateral direction outer side of the flange body 54 and a plurality of mountings arranged along the ring body 51. Provide holes. Then, the mounting surface is brought into contact with the vehicle inner side surface at the front end of the body frame (side member) 12, and the mounting holes of the body frame (side member) 12 and the mounting holes of the flange body 54 are penetrated to form a plurality of bolts. By fastening the nut 56, the axle housing 2 is fixed to the vehicle body frame 12 via the bracket 50.

  As shown in FIGS. 3 to 5, the mast support portion 52 of the ring body 51 in the bracket 50 includes a lower frame 57 </ b> B of a mast 57 that includes a lift cylinder 57 </ b> A that is a working machine as a forklift and moves up and down. 57C is attached so as to be swingable in the front-rear direction. Although not shown, the mast 57 including the lift cylinder 57A is freely tiltable (forward / backward tilt) over a predetermined angle range based on the operation of the tilt cylinder interposed between the vehicle body and the mast 57. It is configured.

  As shown in FIG. 5, the drive axle 1 and the bracket 50 attached to the vehicle body frame face the inner periphery of the ring body 51 with an annular gap with respect to the outer periphery of the attachment flange 3 </ b> A of the axle tube 3. Yes. The bolts arranged in an arc shape on the upper and lower portions of the mounting flange 3A of the axle tube 3 in the figure are mounting bolts 3B for fixing the axle tube 3 to the axle housing 2. For this reason, in a state where the drive axle 1 is attached to the vehicle body by the bracket 50, the axle tube 3 can be detached alone together with its built-in components by loosening the mounting bolt 3B without removing the entire drive axle 1. In this removal, the ring body 51 of the bracket 50 exists on the outer periphery with an annular gap with respect to the mounting flange 3A of the axle tube 3, so that it does not interfere with the tool and does not hinder the removal work. For this reason, the maintainability of the wet brake mechanism 6 and the planetary gear mechanism 7 incorporated in the axle tube 3 is good.

  The torque reaction force generated in the drive axle 1 during driving of the vehicle acts to rotate the drive axle 1 about its axis, but the fixed portion between the axle housing 2 and the plate body 53 of the bracket 50 is Since the distance from the shaft center of the drive axle 1 can be increased, the safety factor against the loosening of the mounting bolt 55 fixing both of them can be increased. In addition, the fixed portion between the axle housing 2 and the plate body 53 of the bracket 50 acts effectively in maintaining the torque reaction force because the vehicle weight component applied to the drive axle 1 acts in the direction in which they are brought into contact with each other. Thus, also in this respect, the loosening safety factor of the mounting bolt 55 can be increased.

  Moreover, the cargo handling mast 57 is directly supported by the vehicle body frame 12 via the bracket 50 by the mast support portion 52. In addition to the vertical load, the load is pushed by the mast 57 or a fork (not shown), so that a load in the front-rear direction also acts on the mast 57. Therefore, for example, in a generally used mode in which the mast 57 is supported by the axle tube 3 of the drive axle 1, it is necessary to design the strength so as to withstand the load in the front-rear direction (including the collision).

  However, in the structure of the present embodiment, since the mast 57 is coupled to the vehicle body frame 12 via the bracket 50, the aforementioned longitudinal load does not act on the axle tube 3 or the axle housing 2, and these are It is received by the body frame 12. For this reason, it is not necessary to design the axle tube 3 and the axle housing 2 to have strengths that take into account the above-described collision load, and can be designed with reasonable strength.

  Also. The mast support portion 52 is a ring body 51 of the bracket 50 and is supported from both above and behind, so that the ring body 51 is not deformed even when the above-described vertical load or front-back load is applied. The mast 57 can be securely held.

  FIG. 8 shows a mounting structure of an industrial vehicle drive axle in the second example of the present embodiment. In the mount structure of the second embodiment, the configuration of the bracket 50 is changed with respect to the first embodiment. That is, the bracket 50 is formed in a shape straddling the axle housing 2 from above. Then, a pair of protrusions 60 provided in the front-rear direction of the axle housing 2 and a boss 61 projecting upward are passed through the respective mounting holes so that the pair of protrusions 60 and the boss 61 of the axle housing 2 are penetrated. The axle housing 2 and the bracket 50 are integrated with each other by screwing the mounting bolt 62. As in the first embodiment, a flange body 54 is integrally provided behind the bracket 50, and a mast support portion 52 is integrally provided in front of the bracket 50. The mounting flange 3A of the axle tube 3 with respect to the axle housing 2 has a configuration in which mounting holes are arranged radially. Other configurations are the same as those of the first embodiment.

  In the present embodiment, the same effect as that of the first embodiment is provided, and the fastening of the axle housing 2 in the vertical direction is performed at the front and rear positions and the upper position, so that the vehicle weight is reduced between the bracket 50 and the axle housing 2. Therefore, the vehicle body frame 12 has an effective shape for effectively transmitting the torque reaction force acting on the drive axle 1 to the bracket 50. Further, the bracket 50, the axle housing 2 and the fixed portion can be configured to be far apart from the central axis of the drive axle 1, and the safety factor against the loosening of the mounting bolt 62 can be obtained in maintaining the torque reaction force acting on the drive axle 1. Can be improved.

  FIG. 9 shows a mounting structure of an industrial vehicle drive axle in the third example of the present embodiment. In the mount structure of the third embodiment, brackets 50 are integrally formed at both ends of the axle housing 2. That is, when the axle housing 2 is formed by casting, the cavities for the bracket 50 are also formed on the mold at the same time, so that both can be integrated. Further, when the axle housing 2 and the bracket 50 are separately formed, they may be integrated by welding or the like. In the case of integration by welding or the like, by forming joint portions of the bracket 50 to both ends of the axle housing 2 in the ring body, it becomes possible to weld all around, and the joint strength can be further increased. The illustrated bracket 50 is formed to be curved in the vehicle width direction in accordance with the difference between the axial dimension of the axle housing 2 and the mounting width dimension of the vehicle body frame 12. Moreover, although the bracket 50 in which the mast support portion is not formed is illustrated, the mast support portion may be formed as in the first and second embodiments.

  In the mount structure of this embodiment, the axle housing 2 and the bracket 50 are integrated, so that both are fixed by fastening means such as mounting bolts as in the first and second embodiments. Thus, the mounting strength and mounting accuracy of the axle housing 2 can be further increased.

  In the above embodiment, the wet brake mechanism 6 and the planetary gear mechanism 7 have been described as being built in the axle tube 3 of the drive axle 1, but although not illustrated, the wet brake mechanism 6, Alternatively, the planetary gear mechanism 7 may be incorporated alone, or other equipment requiring disassembly and maintenance may be incorporated.

  In the present embodiment, the following effects can be achieved.

  (A) An axle housing 2 incorporating the final reduction gear 4 and the differential 5 and an axle hub 24 which incorporates at least one of the wet brake mechanism 6 and the planetary gear mechanism 7 and supports the driving wheel W on the outer periphery on the front end side. An industrial vehicle drive axle 1 is constructed from an axle tube 3 that is rotatably supported and is fixedly disposed on both ends of the axle housing 2 via mounting bolts 3B as fastening means. The axle housing 2 A pair of brackets 50 which are fixedly arranged at both ends of the housing by mounting bolts 55 as first fastening means or integrally formed at both ends of the axle housing 2 are attached to the vehicle body frame 12 by mounting bolts 56 as second fastening means. It is characterized in that it is fastened and fixed to the front part. For this reason, in a state where the drive axle 1 is attached to the vehicle body by the bracket 50, the fastening means for the axle tube 3 can be loosened by removing the fastening means for the axle housing 2 without removing the entire drive axle 1, and can be detached alone together with its built-in components. The maintainability of the wet brake mechanism 6 and the planetary gear mechanism 7 incorporated in the axle tube 3 is good.

  (A) As a first fastening means, the pair of brackets 50 are brought into contact with both end portions of the axle housing 2 from the upper surface, respectively, and a mounting bolt 55 as a fastening element penetrating the contact portion in the vertical direction. Since the axle housing 2 and the bracket 50 are fastened and fixed by the above, the fixing portion between the axle housing 2 and the bracket 50 can take a large distance from the shaft center of the drive axle 1 and safety against loosening of the fastening means fixing both of them. The rate can be increased. Moreover, since the vehicle weight component applied to the drive axle 1 acts in the direction in which the axle housing 2 and the bracket 50 are in contact with each other, the fixed portion between the axle housing 2 and the bracket 50 acts effectively to maintain the torque reaction force. Also in this respect, the safety factor for loosening the mounting bolt can be increased.

  (C) Generally, the mast 57 for cargo handling has a structure that is directly supported by the vehicle body frame 12 via the bracket 50 by the mast support portion 52. In addition to the load in the vertical direction, the load is also pushed on the mast 57 by the mast 57 or fork, so that a load in the front-rear direction also acts. Therefore, for example, in a generally used mode in which the mast 57 is supported by the axle tube 3 of the drive axle 1, it is necessary to design the strength so as to withstand the load in the front-rear direction (including the collision). However, the pair of brackets 50 formed separately or integrally with the axle housing 2 are integrally provided with a mast support portion 52 that supports the mast 57 of the cargo handling device disposed in front of the vehicle. These do not act on the axle tube 3 or the axle housing 2 and are received by the vehicle body frame 12. For this reason, it is not necessary to design the axle tube 3 and the axle housing 2 to have strengths that take into account the above-described collision load, and can be designed with reasonable strength.

  (D) A pair of brackets 50 formed separately or integrally with the axle housing 2 includes an annular ring body 51 that surrounds the end of the axle housing 2 of the drive axle 1, and the ring body 51. Since the mast support portion 52 is integrally provided on the front side of the vehicle, the mast support portion 52 is the ring body 51 of the bracket 50 and is supported from both the upper side and the rear side. The ring body 51 will not be deformed even if acts, and the mast 57 can be reliably held.

The system diagram of the drive mechanism in the industrial vehicle carrying the industrial vehicle drive axle which shows one Embodiment of this invention. Sectional drawing of the drive axle for industrial vehicles containing a mounting structure. The top view containing the mounting structure of the drive axle for industrial vehicles. The front view including a mount structure. The side view including a mounting structure. The perspective view containing a mount structure. The perspective view from the vehicle rear containing a mount structure. The side view of the mounting structure of the drive axle for industrial vehicles in 2nd Example. The perspective view of the mounting structure of the drive axle for industrial vehicles in 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive axle 2 Axle housing 3 Axle tube 4 Final drive device as final reduction gear 5 Differential device as differential device 6 Wet brake mechanism, wet brake 7 Planetary gear mechanism 8 Torque converter 9 Transmission 10 Propeller shaft 11 Engine 12 Car body Frame 20 Housing portion 21 Tube portion 50 Bracket 51 Ring body 52 Mast support portion 53 Plate body 54 Flange body

Claims (4)

An axle housing incorporating a final reduction gear and a differential, and at least one of a wet brake mechanism and a planetary gear mechanism, and an axle hub for supporting a driving wheel on the outer periphery of the tip end thereof is rotatably supported. A drive axle for an industrial vehicle is configured from an axle tube fixedly disposed at both ends of the housing via fastening means,
A pair of brackets fixedly arranged at both ends of the axle housing by first fastening means or integrally formed at both ends of the axle housing are fastened and fixed to the front part of the vehicle body frame by second fastening means. Mounting structure for industrial vehicle drive axles.   In the first fastening means, the pair of brackets are brought into contact with both end portions of the axle housing from the upper surface, respectively, and the axle housing and the bracket are fastened and fixed by fastening elements that penetrate the contact portions in the vertical direction. The drive axle mounting structure for an industrial vehicle according to claim 1.   The pair of brackets formed separately or integrally with the axle housing integrally includes a mast support portion that supports a mast of a cargo handling device disposed in front of the vehicle. Mount structure of the described drive axle for industrial vehicles.   A pair of brackets formed separately or integrally with the axle housing includes an annular ring body that surrounds an end of the axle housing of the drive axle, and a mast support section on the vehicle front side of the ring body The structure for mounting a drive axle for an industrial vehicle according to claim 3, comprising:

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