JP6458789B2 - Work machine - Google Patents

Description

  The present invention relates to a work machine that includes a lower traveling body and an upper swing body, and is provided by welding a beam of a side frame to a center frame of the upper swing body.

  A work machine such as a hydraulic excavator includes a lower traveling body and an upper swing body provided on the lower traveling body. The upper swing body includes a center frame and side frames provided on both left and right sides of the center frame.

  The upper swing body includes a center frame that is rotatably supported by the lower traveling body via a swing bearing portion, and side frames that are provided on both the left and right sides of the center frame.

  The center frame extends in the front-rear direction while supporting the work device on the front side. On the side frame, mounted items such as a driver's seat, a fuel tank, a hydraulic oil tank, a radiator, and a battery are mounted, and are formed by a plurality of beams in order to support the load of these mounted items.

  One end of the beam of the side frame is welded to the center frame. In the welded portion between the center frame and the beam of the side frame, it is necessary to ensure sufficient strength to resist the load applied from the center frame during traveling or the like.

  Therefore, conventionally, in a side frame, a beam having a shape including a pair of beam side plate portions and a beam upper plate portion connected between the upper portions of both beam side plate portions is used. The thing which ensured the intensity | strength by joining to a center frame by welding over which it spreads is proposed (for example, refer the following patent document 1).

JP 2014-214510 A

  However, when the edge of the beam composed of a pair of beam side plate and beam upper plate is abutted against the side surface of the center frame and welded as in the conventional case, the edge of the beam side plate and the beam Since a right-angled corner is formed at the boundary with the edge of the plate part, it is difficult to perform welding work continuously in one step from the edge of the beam side plate part to the edge of the beam upper plate part. is there. For this reason, it is necessary to divide into two processes, the operation of welding the edge of the beam side plate portion to the side surface of the center frame and the operation of welding the edge of the upper plate portion of the beam to the side surface of the center frame. There is a bad inconvenience.

  In addition, the conventional beam having a pair of beam side plate portions and beam upper plate portions has a disadvantage that it is relatively expensive due to its structure. Therefore, it is desirable to use a beam with another simple structure at a position where the load of the load is hardly applied (for example, at the rear side of the center frame). There is a risk that a sufficient strength cannot be obtained.

  In view of the above points, the present invention improves the weldability of the center frame of the upper swing body and the beam of the side frame, provides sufficient strength for the welded portion, and makes the beam a simple structure. It aims at providing the working machine which can suppress a cost increase by this.

In order to achieve such an object, the present invention includes a lower traveling body and an upper revolving body that is turnably provided on the lower traveling body, and the upper revolving body supports a work device in a front-rear direction. In a working machine comprising a center frame extended to a side frame and a side frame formed by a beam welded to a side surface of the center frame, the beam is in the form of a strip extending in a crossing direction with respect to the center frame. a base, and a reinforcing member attached to the front-rear direction one plate surface facing the base portion, said base portion and said reinforcing member are both welded to the center frame, wherein the reinforcing member of the base A contact surface that contacts the plate surface , and an exposed portion that is formed on the same plane as the corresponding contact surface and is exposed from the upper edge of the base portion, and the beam is exposed from the upper edge of the base portion and the reinforcing member. Steps formed by Fill comprising a first weld portion, said center frame includes a second weld that is continuous with the side surface of the center frame from the reinforcing member in contact state toward the base of the abutment to the side of the center frame through the upper first weld It comprises a part.

  The first weld fills a step formed by the upper edge of the base of the beam and the exposed portion of the reinforcing member. Accordingly, a right-angled corner is not formed at the boundary between the beam and the reinforcing member, and a continuous surface can be formed by the first welded portion from the upper surface of the reinforcing member to the upper edge of the beam.

  And when forming the said 2nd weld part, since it can continuously weld in one process from the reinforcement member of a contact state to the side surface of a center frame along the surface continuous by a 1st weld part, and a beam Good weldability.

  Further, the base portion of the beam is shaped like a band plate, and the reinforcing member is provided at the contact position with respect to the center frame, thereby simplifying the structure of the beam and suppressing an increase in cost. A strong weld can be formed by two welds.

  As described above, according to the present invention, the weldability of the center frame of the upper swing body and the beam of the side frame is improved, sufficient strength is obtained at the welded portion, and the structure of the beam is simplified and the cost is reduced. It is possible to provide a work machine that can suppress the increase.

  In the present invention, the exposed portion of the reinforcing member is exposed from an upper edge of the notch formed in the base of the beam, and the first welded portion is the notched portion and an exposed portion of the reinforcing member. It is characterized in that it is formed by filling the step formed by.

  The notch is formed in the beam, and by exposing the exposed portion of the reinforcing member from the upper edge of the notch, the height of the beam can be suppressed without reducing the strength of the welded portion. According to this, even if an overhanging portion that protrudes above the beam from the upper edge of the center frame is formed, the beam is welded to the side surface of the center frame without causing a welding torch or the like to interfere with the overhanging portion of the center frame. And higher weldability can be obtained.

  Further, when the exposed portion of the reinforcing member is exposed from the upper edge of the notch formed in the beam, the beam is inclined toward the upper edge excluding the notch from the upper edge of the notch. It comprises a part.

  By forming the inclined part, the upper part of the step formed by the notch part and the exposed part can be opened relatively widely. For example, during welding of the first welded part or the second welded part Interference between the welding torch and the base of the beam can be prevented, and welding workability is improved.

  Further, when the exposed portion of the reinforcing member is exposed from the upper edge of the notch formed in the beam, the surface of the reinforcing member that contacts the plate surface of the base of the beam is adjacent to the exposed portion. A chamfered portion is provided at the upper corner portion, and a third welded portion continuing from the first welded portion is provided between the chamfered portion and the plate surface of the beam.

  By providing the third welded portion, the reinforcing member can be provided more firmly. And since the welding from a 1st weld part to a 3rd weld part can be performed by 1 process continuously by the said chamfering part, the attachment strength of a reinforcement member can be improved, without reducing welding workability.

The side view which shows the structure of a hydraulic shovel. The perspective view which shows the turning frame of embodiment of this invention. The perspective view which shows the principal part of the beam of this embodiment. Explanatory sectional drawing of the principal part of the beam of this embodiment. The perspective view which shows the principal part of the beam of this embodiment. Explanatory top view of the principal part of the beam of this embodiment. Explanatory drawing which shows the welding operation | work of the beam of this embodiment. The perspective view which shows the modification of a reinforcement member. The perspective view which shows the modification of a reinforcement member.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a hydraulic excavator 1 as a work machine includes a lower traveling body 2, an upper swinging body 4 provided on the lower traveling body 2 through a swing bearing portion 3, and an upper swinging body. 4 is provided with a work device 5 provided on the machine 4. A cab 6 is mounted on the front side of the upper swing body 4, and a machine room 7 such as an engine and a counterweight 8 are mounted on the rear side.

  The upper swing body 4 includes a swing frame 9 shown in FIG. 2, and the swing frame 9 is provided on a side of each center frame 10 and a pair of center frames 10 that are rotatably supported by the swing bearing portion 3. And a side frame 11. Both center frames 10 are provided in parallel with each other with the horizontal direction extending in the front-rear direction as the longitudinal direction.

  The center frame 10 is formed at the highest position where a later-described boom foot pin mounting hole 14 located in the vicinity of the turning center is formed, and the rear side of the machine body is formed low.

  The center frame 10 includes a side surface portion 10a, an upper surface portion 10b that is integrally provided on the upper portion of the side surface portion 10a and projects laterally, and a bottom surface that is integrally provided on the lower portion of the side surface portion 10a and projects laterally. An I-shaped cross section is formed by the portion 10c.

  The side frame 11 is composed of a plurality of beams 12 and a frame member 13. Each beam 12 is formed in a longitudinal direction in a direction intersecting the center frame 10, and one end thereof is welded to the center frame 10 and provided integrally with the center frame 10. Mounted items such as a cab 6, a fuel tank, a hydraulic oil tank, a radiator, and a battery are mounted on the side frame 11.

  As shown in FIG. 1, a boom 16 and a boom cylinder 17 that rotates the boom 16 are pivotally supported in the boom foot pin mounting hole 14 and the boom cylinder mounting hole 15 of the center frame 10. 18 is pivotally supported so as to be rotated by an arm cylinder 19, and a bucket 20 is pivotally supported at the tip of the arm 18 so as to be rotated by a bucket cylinder 21.

  Here, among the beams 12 shown in FIG. 2, a beam according to the gist of the present invention (hereinafter referred to as a rear beam 120) welded to the rear side of the center frame 10 will be described. As shown in an enlarged view in FIG. 3, the rear beam 120 includes a strip-like base 121 having a horizontal bent portion along the lower edge, and a reinforcing member 122 fixed to the front side of the base 121. Yes.

  A notch 121a is formed above one end of the base 121 (the end on the side welded to the center frame 10). Further, an inclined portion 121b is formed which is continuous with the notch 121a and is inclined in a direction of gradually rising toward the upper edge of the base 121.

  The reinforcing member 122 has a thickness dimension larger than that of the base portion 121, and a rear surface (contact surface) is in contact with the plate surface of the base portion 121 with the thickness direction directed up and down. At this time, an exposed portion 122a exposed from the upper edge of the notch 121a is formed on a part of the same surface as the contact surface of the reinforcing member 122. A step 123 is formed between the exposed portion 122a and the upper edge of the notch 121a.

  As shown in FIG. 4, the first welded portion 22 is formed by welding the step 123 formed by the upper edge of the notch 121 a and the exposed portion 122 a of the reinforcing member 122. By forming the first welded portion 22, the boundary between the upper edge of the base 121 and the reinforcing member 122 is not an angular shape but a smoothly connected shape at one end edge of the rear beam 120. As a result, when one end edge of the rear beam 120 is welded to the side surface of the center frame 10, welding can proceed without interruption at the boundary between the base 121 and the reinforcing member 122, and from the base 121 to the reinforcing member 122. A continuous second welded portion 23 is formed via the first welded portion 22.

  In addition, as shown in FIG. 5, the reinforcing member 122 has a chamfered portion 122 b formed at the upper corner from the surface that contacts the plate surface of the base 121 to a part of the exposed portion 122 a.

  When the base 121 and the reinforcing member 122 are integrally joined by welding the chamfered portion 122b, a third welded portion 24 is formed at the position of the chamfered portion 122b as shown in FIG. The base 121 and the reinforcing member 122 are more firmly integrated by the third welded portion 24. Moreover, the 3rd welding part 24 and the 1st welding part 22 can be formed continuously, and not only the joining strength by welding improves but welding construction becomes easy.

  Furthermore, part of the chamfered part 122b of the reinforcing member 122 is formed to extend to part of the exposed part 122a, so that part of the chamfered part 122b is exposed from the upper edge of the notch part 121a. According to this, when forming the 3rd welding part 24 and the 1st welding part 22 continuously, the boundary part of the 3rd welding part 24 and the 1st welding part 22 can be welded smoothly, Since the “throat thickness” can be increased, the welding strength can be secured.

  In addition, in order to show the principal part of the structure of the rear beam 120 in detail, in FIG.2, FIG3 and FIG.5, illustration of the 1st welding part 22, the 2nd welding part 23, and the 3rd welding part is abbreviate | omitted.

  The rear beam 120 having the above-described configuration is provided with the notch 121a in the base 121, so that a work space for the welding torch 25 can be secured during welding for forming the second weld 23 as shown in FIG. The welding work can be performed without the welding torch 25 interfering with the protruding portion of the upper surface portion 10b of the center frame 10. Furthermore, since the inclined part 121b is formed in the base 121 of the rear beam 120, the interference of the welding torch 25 to the base 121 can also be prevented.

  Further, as shown in FIG. 4, a step 123 formed by the upper edge of the base 121 of the rear beam 120 (upper edge of the notch 121 a) and the exposed portion 122 a of the reinforcing member 122 is filled with the first welded portion 22. Thus, a strong joined state between the base 121 and the reinforcing member 122 can be formed. In addition, as described above, the first welded portion 22 smoothly connects the boundary between the base portion 121 and the reinforcing member 122, so that the second welded portion 23 that is continuous between the base portion 121 and the reinforcing member 122 is formed to form the rear beam 120. And the center frame 10 can be firmly joined.

  Then, like the rear beam 120 of the present embodiment, the reinforcing member 122 is connected to the strip-shaped base 121, and a joining state with the center frame 10 is formed by the second welded portion 23 continuous from the base 121 to the reinforcing member 122. By doing so, the structure of the beam can be simplified and the cost can be reduced while the strength of the rear beam 120 is sufficiently improved.

  In the rear beam 120, as shown in FIGS. 8 and 9, a reinforcing member 124 having another shape can be provided. That is, the exposed portion 124a is formed by exposing the upper side portion of the reinforcing member 124 from the upper edge of the cutout portion 121a of the base portion 121, and the upper edge of the cutout portion 121a of the base portion 121 and the exposed portion 124a. The first welded portion 22 can be formed on the step 123.

  In the present embodiment, the rear beam 120 welded to the rear side of the center frame 10 as the beam according to the present invention has been described. However, the configuration of the present invention can be applied to beams 12 other than the rear beam 120. is there.

  Further, in the present embodiment, the hydraulic excavator 1 is shown as a work machine, but the present invention is not limited to this, and is applicable to, for example, a self-propelled crane or the like although not shown.

  DESCRIPTION OF SYMBOLS 1 ... Hydraulic excavator (work machine), 2 ... Lower traveling body, 4 ... Upper turning body, 10 ... Center frame, 11 ... Side frame, 12 ... Beam, 120 ... Rear beam (beam), 121 ... Base, 121a ... Cutting Notched portion, 121b ... inclined portion, 122 ... reinforcing member, 122a ... exposed portion, 122b ... chamfered portion, 123 ... step, 22 ... first welded portion, 23 ... second welded portion, 24 ... third welded portion

Claims (4)

A center frame provided with a lower traveling body and an upper revolving body provided on the lower traveling body so as to be capable of swiveling, the upper revolving body supporting a work device and extending in the front-rear direction; and the center frame In a work machine comprising a side frame composed of beams welded to the side surface of
The beam includes a strip-shaped base portion extending in a crossing direction with respect to the center frame, and a reinforcing member attached to one plate surface facing the front-rear direction of the base portion, and the base portion and the reinforcing member are Both are welded to the center frame,
The reinforcing member includes a contact surface that contacts the plate surface of the base , and an exposed portion that is formed on the same plane as the corresponding contact surface and is exposed from the upper edge of the base.
The beam includes a first weld that fills a step formed by an upper edge of the base and an exposed portion of the reinforcing member,
The center frame includes a second welded portion that continues from a reinforcing member in contact with a side surface of the center frame to a base portion in contact with the side surface of the center frame through the first welded portion. Work machine.   The exposed portion of the reinforcing member is exposed from an upper edge of a notch formed at the base of the beam, and the first welded portion is a step formed by the notched portion and the exposed portion of the reinforcing member. The working machine according to claim 1, wherein the working machine is formed by filling   The work machine according to claim 2, wherein the beam includes an inclined portion that extends from an upper edge of the notch portion to an upper edge excluding the notch portion.   A chamfered portion is provided at an upper corner adjacent to the exposed portion of the surface of the reinforcing member that contacts the plate surface of the base portion of the beam, and the first welded portion is provided between the chamfered portion and the plate surface of the beam. 4. A work machine according to claim 2, further comprising a third welded portion that is continuous with the third welded portion.

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