JP5626231B2 - Cabin roof guard device for construction machinery - Google Patents

Description

  The present invention relates to a cabin roof guard device for protecting a roof with a skylight of a cabin (cab) from a fallen object in a construction machine such as an excavator.

  As shown in FIGS. 5 and 6, for example, a cabin 1 of an excavator is provided with a skylight 2 for securing an upper view, and a roof 3 for protecting the roof 3 including the skylight 2 from falling objects such as falling rocks. A guard 4 is mounted on the roof 3 to constitute a cabin roof guard device (see Patent Documents 1 to 3).

  In FIG. 5, 5 is a front upper guard device that covers the upper part of the front surface of the cabin, and 6 is a front lower guard device that covers the lower part.

  In FIG. 5, a cabin roof guard device (hereinafter simply referred to as a roof guard device) is illustrated as a front protection type device that protects only the front half of the roof 3, but the entire roof surface is collectively covered. Some are fully protective. In this case, the front half that covers the skylight 2 has a lattice structure in order to secure an upper field of view.

  Also, a front and rear separation type device that is provided separately for a front roof guard device that protects the front half of the roof including the skylight 2 and a rear roof guard device that protects the rear half is also known.

  The present invention can be applied to any of a front guard roof guard device, a full guard roof guard device, and a front roof guard device in a front / rear separation type.

  As shown in FIGS. 6 to 8, the roof guard 4 includes left and right side frames 7 and 7 and a lattice portion 8 attached to the inside of the both side frames 7 and 7. In FIG. 7, reference numeral 9 denotes a rear plate attached between the rear end portions of the side frames 7 and 7.

  The lattice portion 8 includes a plurality of front and rear horizontal beams 10 whose both ends are welded to the inner side surfaces of both side frames 7 and 7, and a plurality of vertical beams 11 attached between adjacent horizontal beams spaced from each other on the left and right. It is a lattice structure.

  In the conventional roof guard device, as shown in FIGS. 6 and 8, from the viewpoint of securing sufficient strength and rigidity so that both side frames 7 and 7 constituting the roof guard 4 are not deformed against a drop load. It is formed in a square closed cross section, that is, a square cylinder.

Japanese Utility Model Publication No. 4-53855 JP-A-8-109658 JP 2006-177117 A

  However, since both side frames 7 and 7 are configured with high strength and high rigidity, the lattice portion 8 is simply a combination of flat and vertical members so as not to obstruct the upper field of view. Compared to the above, strength and rigidity are lowered. That is, the gap between the strength and rigidity of the side frames 7 and 7 and the lattice portion 8 is increased.

  As a result, when a load W (see FIG. 8) due to a falling object is applied to the lattice portion 8, the load is concentrated on the lattice portion 8 without being distributed to both the side frames 7 and 7 and the roof 3.

  As a result, the stress of the lattice portion 8 at the time of the load action increases, and the displacement amount α of the lattice portion 8 itself is suppressed by the side frames 7 and 7, but the damage received by the lattice portion 8 increases. Is easily damaged (so-called “grid cut”).

  For this reason, it is disadvantageous in terms of a protective function for a roof guard device that has a higher probability of falling objects hitting the lattice portion 8 than both side frames 7 and 7.

  Moreover, the following problem has arisen by making both the side frames 7 and 7 into a closed cross section.

  (i) As shown in FIG. 6, since both side frames 7 and 7 enter the field of view through the skylight 2 when viewed from inside the cabin 1, the field of view (work field of view) θ effective at the time of work is narrowed.

  (ii) Since the side frames 7 and 7 are constructed by welding a pair of L-shaped members, the amount of welding increases, which increases the cost and weight.

  In FIG. 6, P is a standard viewpoint (eye point) of the operator in the cabin.

  As a solution to the above problem (i), it is conceivable to increase the width dimension (guard width) of the entire roof guard 4 so that the side frames 7 and 7 do not obstruct the field of view. Since the guard 4 protrudes outside the roof width and becomes an obstacle during work or truck transportation of the machine, it is not a good idea.

Accordingly, the present invention provides a cabin roof for a construction machine that can prevent stress damage on the grid portion with respect to a drop load, prevent the breakage thereof, improve the upper working field of view without increasing the guard width, and reduce the cost. A guard device is provided.

As means for solving the above-mentioned problem, in the present invention, a roof guard having left and right side frames and a lattice portion including a horizontal beam whose both ends are welded to both side frames is provided for a cabin equipped with a skylight. In a cabin roof guard device for a construction machine, which is mounted on the roof top surface so as to cover the skylight, the both side frames are formed in an L-shape consisting of a vertical side and a horizontal side in a sectional view, and the vertical side is facing upward. The roof guard is constructed by connecting the side frames and the lattice portion in a state of being positioned outside in the width direction and having the horizontal beam spanned between the horizontal sides.

  According to this configuration, the strength / rigidity gap between the side frames and the lattice portion is reduced, and when a drop load is applied to the lattice portion, the both side frames are pulled by the lattice portion and displaced inward. That is, the load is transmitted not only to the lattice portion but also to the roof through both side frames and both side frames, and is distributed over a wide range.

  As a result, although the displacement of the roof guard as a whole is larger than the conventional one, the stress acting on the lattice portion is reduced.

  Further, when the amount of displacement of the lattice portion reaches a certain value, the lattice portion interferes with the roof, so that energy is absorbed and the displacement of the lattice portion is suppressed.

  From the above points, it is possible to prevent the lattice portion from being damaged by a drop load and to improve the protective effect of the roof guard.

In addition, by making both side frames L-shaped open cross-sectional shape, and by positioning the vertical side upward and outside the roof width direction ,
(I) Since the possibility that both side frames enter the view from inside the cabin is reduced, the upper working view is improved without increasing the guard width,
(II) When welding the vertical side and the horizontal side as separate members, the welding amount can be greatly reduced and the cost can be reduced compared to the closed cross-section side frame of the conventional device,
(III) Both side frames can be reduced in weight.

  In the present invention, the roof guard is dimensioned so that the vertical sides of both side frames are located within the roof width of the cabin, and the horizontal side is located outside the width of the skylight, and is attached to the upper surface of the roof. Desirable (Claim 2).

According to this configuration, the upper work view from the cabin can be enlarged while satisfying the condition that the roof guard does not protrude outside the roof width.

  In the present invention, the vertical side and the horizontal side of both side frames of the roof guard may be integrally formed in an L shape.

  In this way, the side frame can be configured without welding, and thus further cost reduction and weight reduction can be realized.

According to the present invention, it is possible to avoid the stress concentration of the lattice portion with respect to the drop load, prevent the breakage, improve the upper working field of view without increasing the guard width, and reduce the cost.

It is a perspective view of a cabin provided with a roof guard device concerning an embodiment of the present invention. It is the II-II line expanded sectional view of FIG. It is a perspective view of the roof guard which concerns on embodiment. It is a partially expanded sectional view of the roof guard. It is a side view of the cabin provided with the conventional roof guard apparatus. It is the VI-VI line expanded sectional view of FIG. It is a perspective view of the conventional roof guard. It is a partially expanded sectional view of the conventional roof guard.

  An embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the roof guard 13 according to the embodiment is attached to the upper surface of the roof 3 including the skylight 2 of the cabin 1 to constitute the roof guard device according to the embodiment.

  The roof guard 13 is basically constituted by left and right side frames 14 and 14 and a lattice portion 15 attached to the inside of the both side frames 14 and 14 as in the prior art. In FIGS. 1 and 3, reference numeral 16 denotes a rear plate attached between the rear ends of the side frames 14 and 14.

In the embodiment, as shown in FIGS. 2 to 4, both side frames 14 and 14 are formed in a substantially L shape including a vertical side 14 a and a horizontal side 14 b in a cross-sectional view, and the vertical side 14 a is in the guard width direction (roof roof). Width side ) and the horizontal side 14b are located inside ,
(ii) The vertical side 14a faces upward
In this state, it is coupled with the lattice portion 15.

  The vertical side 14a and the horizontal side 14b are each formed of a flat plate, and the side frame 14 is configured by welding and joining them in a substantially L shape.

  However, the vertical and horizontal sides 14a and 14b may be integrally formed in an L shape (a member having an L-shaped cross section may be used).

  The lattice unit 15 has a lattice structure by a plurality of front and rear horizontal beams 17 and a number of vertical beams 18 attached between adjacent horizontal beams with a space left and right.

  Each crosspiece 17 has its abutment portion (at least a contact portion with the horizontal side 14b) in a state where both end portions are in contact with the upper surface of the horizontal side 14b of both side frames 14, 14 and the inner side surface of the vertical side 14a. It is fixed by welding.

  As shown in FIG. 2, the roof guard 13 is dimensioned so that the vertical sides 14 a of both side frames 14, 14 are located within the width A of the roof 3 and the horizontal sides 14 b are located outside the width B of the skylight 2. Set and mounted on the roof top.

  The horizontal beam 17 and the vertical beam 18 are attached in an inclined posture along the line of sight from the eye point P (see FIG. 4) so as not to obstruct the upper view from the cabin 1 respectively.

  According to this roof guard device, both side frames 14 and 14 are formed in an L shape having a vertical side 14a and a horizontal side 14b in a cross-sectional view, and a plurality of cross rails 17 are formed on the horizontal sides 14b and 14b of both side frames 14 and 14. Since the roof guard 13 is configured by connecting the side frames 14 and 14 and the lattice portion 15 in a state of being sandwiched between them, the gap between the strength and rigidity of the side frames 14 and 14 lattice portion 15 is reduced.

  As a result, as shown in FIG. 4, when a drop load W acts on the lattice portion 15, both side frames 14, 14 are pulled by the lattice portion 15 and displaced inward. That is, the load W is transmitted to the roof 3 not only through the lattice portion 15 but also through the side frames 14 and 14 and the side frames 14 and 14, and is distributed over a wide range.

  As a result, although the displacement amount β of the entire roof guard is larger than that of the conventional roof guard, the stress acting on the lattice portion 15 is reduced.

  When the displacement amount β of the lattice portion 15 reaches a certain value, the lattice portion 15 interferes with the roof 3 so that energy is absorbed and the displacement of the lattice portion 15 is suppressed.

  From the above points, damage to the lattice portion 15 due to the drop load W can be suppressed and the breakage can be prevented, and the protective effect by the roof guard 13 can be improved.

  The inventor analyzed the product of the present invention and the conventional product shown in FIGS.

In the analysis, a load is applied to the central portion of the lattice portions 15 and 8 that affect the side frames 14 and 7 (
(FOPS-II level) was added.

condition is,
Product of the present invention Thickness 3.2 mm of both side frames 14, 14
Conventional product Thickness of both side frames 7, 7 2.3mm
The thicknesses of the horizontal bars 17 and 10 and the vertical bars 18 and 11 of the lattice portions 15 and 8 were both 6 mm.

  As a result, the amount of displacement of the grating portions 15 and 8 was 173.6 mm for the product (β) of the present invention and 142.9 mm for the conventional product (α).

  On the other hand, the stress of the lattice portions 15 and 8 was 494.6 N / square mm for the product of the present invention, and 632.5 N / square mm for the conventional product.

  That is, although the displacement amount β of the lattice portion 15 increases, the stress acting on the lattice portion 15 is lower than that of the conventional product.

  In the conventional product, the stress of the side frame 7 is generated only at the coupling portion with the lattice portion 8, and the stress is concentrated on the lattice portion 8 correspondingly, whereas in the present invention product, the stress is concentrated from the lattice portion 15 to the side frame 14. It is understood that stress is transmitted to and distributed.

Moreover, the following effects can be acquired by making both the side frames 14 and 14 into the L-shaped open cross-section shape , and the vertical edge | side 14a facing upwards and the outer side of a roof width direction .

(I) The possibility that both the side frames 14 and 14 enter the upper work view from the cabin 1 is reduced.

In this case, in the embodiment, the dimension is set so that the vertical side 14a of both side frames 14 and 14 is located within the width A of the roof 3, and the horizontal side 14b is located outside the width B of the skylight 2, and the top surface of the roof is formed. Since it is attached, the possibility that both side frames 14 and 14 enter the upper working field of view through the skylight 2 from the cabin 1 becomes lower, and the field of view θ2 shown in FIG. Can also be spread reliably.

  (II) When the vertical side 14a and the horizontal side 14b are welded as separate members as in the embodiment, the welding amount can be greatly reduced and the cost can be reduced as compared with the closed cross-section side frame 7 of the conventional apparatus.

  (III) Both side frames 14, 14 can be reduced in weight.

  If the vertical sides 14a and the horizontal sides 14b of the side frames 14 and 14 are integrally formed in an L shape, the side frames 14 and 14 can be configured without welding, so that further cost reduction and weight reduction can be realized. it can.

DESCRIPTION OF SYMBOLS 1 Cabin 2 Skylight 3 Roof 13 Roof guard 14,14 Both right-and-left side frames 14 Both side frames 14a Side frame vertical side 14a Same, horizontal side 15 Lattice part 17 Lattice side crosspiece 18 Same, vertical beam

Claims (3)

A construction in which a roof guard having left and right side frames and a lattice portion including a horizontal beam welded to both side frames at both ends is attached to the top surface of a cabin having a skylight so as to cover the skylight. In a cabin roof guard device of a machine, the both side frames are formed in an L shape having a vertical side and a horizontal side in a cross-sectional view, the vertical side is upward and located on the outer side in the roof width direction, and the horizontal rail A roof roof guard device for a construction machine, wherein the roof guard is constructed by connecting the side frames and the lattice portion in a state where the roof frame is bridged between the horizontal sides.   The roof guard is dimensioned so that the vertical sides of both side frames are positioned within the roof width of the cabin and the horizontal side is positioned outside the width of the skylight, and is attached to the top surface of the roof. The cabin roof guard device for a construction machine according to claim 1.   3. The cabin roof guard device for a construction machine according to claim 1, wherein the vertical side and the horizontal side of both side frames of the roof guard are integrally formed in an L shape.

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