JP6587824B2 - Upper swing body of construction machinery - Google Patents

Description

  The present invention relates to an upper swing body of a construction machine.

  For example, Patent Document 1 discloses a conventional upper swing body. The upper swing body described in FIG. 2, paragraphs [0034] and [0038] of the same document includes a center frame and a left side frame. The left side frame is attached to the left side of the center frame via a cab support frame and a beam. As described in [0039] of the document, the cab support frame supports the cab (operator's cab) from below.

JP 2006-168941 A

  In the upper swing structure having the same structure as that of Patent Document 1, a vibration source such as an engine is mounted on a deck (left side frame and beam in the same document) on the rear side of the cab deck (the cab support frame in the same document). There is a case. In this case, vibration is transmitted from the deck on which the vibration source is mounted (hereinafter referred to as the engine deck) to the cab deck, and vibration and noise in the cab may become a problem.

  In order to suppress vibration transmission from the engine deck to the cab deck, as shown in FIG. 8, there is one in which the engine deck 520 and the cab deck 530 are separated (a gap S is provided). In such a structure, a vibration mode in which the cab deck is deformed in the vertical direction Z while being deformed in the lateral direction X is dominant over other vibration modes. As a result, the vibration in the cab mounted on the cab deck increases, and this vibration may adversely affect the ride comfort in the cab.

  Further, the cab deck and the turning frame are connected by a support beam. In order to suppress the vibration of the cab deck in the above vibration mode, it is conceivable to enlarge this support beam. However, if the support beam is made larger, the mass of the support beam increases, and as a result, the mass of the upper swing body increases.

  Then, an object of this invention is to provide the upper revolving body of a construction machine which can suppress the vibration of a cab deck and can suppress the mass of a support beam.

  The upper revolving structure of the construction machine of the present invention includes a revolving frame having a front plate that connects vertically opposed vertical plates, an engine deck, a cab deck, and a support beam. The engine deck is disposed laterally outward from the revolving frame and is fixed to the revolving frame. The cab deck is disposed in front of the engine deck with a gap between the cab deck and the engine deck. The support beam is connected to the swivel frame and the cab deck. The support beam is disposed so as to overlap the front plate when viewed from the side.

  With the above configuration, vibration of the cab deck can be suppressed and the mass of the support beam can be suppressed.

1 is a perspective view of an upper swing body 1. FIG. FIG. 2 is an enlarged view around a support beam 40 shown in FIG. 1. It is the figure which looked at the support beam 40 periphery shown in FIG. 1 from the top. It is F4-F4 arrow sectional drawing of FIG. FIG. 6 is a view corresponding to FIG. 3 of an upper swing body 201 of a modified example. FIG. 4 is a view corresponding to FIG. 3 of an upper swing body 301 of a comparative example. FIG. 4 is a view corresponding to FIG. 3 of an upper swing body 401 of a comparative example. It is a perspective view which shows the cab deck etc. of the conventional upper revolving body.

  The upper swing body 1 according to the embodiment of the present invention will be described with reference to FIGS.

  The upper swing body 1 (low vibration deck structure, crane deck support structure) is used for construction machines. The construction machine in which the upper swing body 1 is used is, for example, a crane, for example, a mobile crane. The upper swing body 1 is mounted on a lower travel body (not shown) and can swing with respect to the lower travel body. The upper swing body 1 includes a swing frame 10, an engine deck 20, a cab deck 30, and a support beam 40.

  The turning frame 10 (center section) is attached to a lower traveling body (not shown). A center line of the revolving frame 10 that extends in the longitudinal direction of the revolving frame 10 is defined as a center line 10c. A direction orthogonal to the longitudinal direction of the swivel frame 10 and a horizontal direction is defined as a lateral direction X. In the lateral direction X, a side approaching the center line 10c is defined as a lateral direction inner side X1, and a side away from the center line 10c is defined as a lateral direction outer side X2. The longitudinal direction of the revolving frame 10 is defined as the front-rear direction Y. In the front-rear direction Y, the cab deck 30 side with respect to the engine deck 20 is a front side Y1, and the opposite side to the front side Y1 is a rear side Y2. A direction (vertical direction) orthogonal to the front-rear direction Y and the lateral direction X is defined as an up-down direction Z. In the vertical direction Z, there are an upper side Z1 and a lower side Z2. The revolving frame 10 includes a bottom plate 11 (lower plate), a vertical plate 13, a boom mounting bracket 14, a front plate 15, and a revolving frame reinforcing portion 17 (see FIG. 3).

  The vertical plate 13 is a plate-like structure extending in the up-down direction Z and the front-back direction Y. The thickness direction of the vertical plate 13 is the horizontal direction X. A plurality of the vertical plates 13 are provided, for example, two (or more than two) may be provided. The vertical plate 13 protrudes from the bottom plate 11 to the upper side Z1, and more specifically, protrudes from both ends (or substantially both ends) of the laterally outer side X2 of the bottom plate 11 to the upper side Z1. The vertical plate 13 includes a first vertical plate 13A and a second vertical plate 13B. The first vertical plate 13A and the second vertical plate 13B (the plurality of vertical plates 13) face each other in the horizontal direction X. The second vertical plate 13B is disposed closer to the cab deck 30 than the first vertical plate 13A.

  As shown in FIG. 3, a boom foot Bf at the base end of the boom B (specifically, the lower boom) is attached to the boom mounting bracket 14. The boom mounting bracket 14 is provided at the upper Z1 end of the front Y1 end of the vertical plate 13.

  The front plate 15 is a plate-like structure that connects (connects) the first vertical plate 13A and the second vertical plate 13B (a plurality of vertical plates 13). More specifically, one end in the horizontal direction X of the front plate 15 is fixed to the first vertical plate 13A. The other end in the horizontal direction X of the front plate 15 is fixed to the second vertical plate 13B. The lower Z2 end of the front plate 15 is fixed to the bottom plate 11. The front plate 15 is fixed to the substantially front end Y1 of the vertical plate 13. The thickness direction of the front plate 15 is the front-rear direction Y (or substantially the front-rear direction Y).

  As shown in FIG. 3, the swivel frame reinforcing portion 17 connects the front plate 15 and the second vertical plate 13B, and reinforces the joint portion between the front plate 15 and the second vertical plate 13B. The turning frame reinforcing portion 17 is, for example, a combination of plate-like members (ribs), and is, for example, hollow and may be solid. The swivel frame reinforcing portion 17 has, for example, a triangular prism shape, is triangular when viewed from the vertical direction Z, and is long in the vertical direction Z as shown in FIG.

  As shown in FIG. 1, the engine deck 20 is a structure (frame) on which a vibration source such as an engine (not shown) is mounted. The engine deck 20 may be mounted with a vibration source (such as a hydraulic pump (not shown)) other than the engine. The engine deck 20 is disposed on the laterally outer side X2 from the revolving frame 10, is fixed to the revolving frame 10, and is fixed to the second vertical plate 13B.

  The cab deck 30 is a structure (frame) on which a cab (not shown, cab) is mounted. The cab deck 30 is disposed on the laterally outer side X2 from the revolving frame 10, is fixed to the revolving frame 10, and is fixed to the second vertical plate 13B. The cab deck 30 is disposed so as to face the engine deck 20 in the front-rear direction Y, and is disposed on the front side Y1 from the engine deck 20. The cab deck 30 is not directly connected to the engine deck 20 (in other words, disconnected). The cab deck 30 is disposed with a gap S (gap S in the front-rear direction Y) between the engine deck 20 and the cab deck 30. The clearance S is provided so that the vibration of the engine deck 20 is not directly transmitted to the cab deck 30. The cab deck 30 includes a frame portion 31, a cab mount 33 shown in FIG. 2, and a cab deck reinforcing portion 35.

  The frame portion 31 constitutes the outer peripheral portion (the outer peripheral portion viewed from the vertical direction Z) of the cab deck 30. The frame portion 31 is rectangular (including a substantially rectangular shape) when viewed in the vertical direction Z and is long in the front-rear direction Y. The frame part 31 is comprised by the plate-shaped member etc. which are extended in the up-down direction Z, for example. The frame portion 31 includes a plate 31f constituting the front side Y1 portion of the frame portion 31, a plate 31r constituting the rear side Y2 portion of the frame portion 31, and an outer side plate 31o constituting the laterally outer side X2 portion of the frame portion 31. , And an inner side plate 31i constituting the X1 portion in the lateral direction of the frame portion 31. The inner side plate 31i and the second vertical plate 13B are opposed to each other in the lateral direction X.

  The cab mount 33 is a portion (cab attachment portion) to which a cab (not shown) is attached. The cab mount 33 is fixed to the frame 31 and is, for example, integral with the frame 31, or may be separate from the frame 31, for example. The cab mount 33 extends in the lateral direction X from the upper Z1 end of the frame portion 31. The cab mount 33 protrudes from the frame part 31 to the inner side (area surrounded by the frame part 31) from the frame part 31 when viewed from the vertical direction Z. The cab mount 33 is provided in, for example, six parts of the frame portion 31 (may be provided in five or less parts or seven or more parts). Among the plurality of cab mounts 33, a cab mount 33a is provided at a position between the front Y1 end and the rear Y2 end of the inner side plate 31i.

  The cab deck reinforcing portion 35 is a portion that reinforces the cab deck 30 and is fixed to the frame portion 31. The cab deck reinforcing portion 35 includes, for example, a cab mount reinforcing portion 35a and a beam 35b. The cab mount reinforcing portion 35 a is a portion that reinforces the cab mount 33 with respect to the frame portion 31, and is connected (fixed) to the frame portion 31 and the cab mount 33. In FIG. 2, only a part of the plurality of cab mount reinforcing portions 35 a is denoted by a reference numeral. The cab mount reinforcing portion 35 a is, for example, a plate-like member (rib), and is disposed so as to be orthogonal to the frame portion 31 and the cab mount 33. The beam 35 b is a portion that reinforces the frame portion 31, is connected (fixed) to the outer side plate 31 o and the inner side plate 31 i, and extends in the lateral direction X. The beam 35 b is a rod-like or plate-like member, and is arranged so as to be orthogonal to the frame portion 31. For example, a plurality of beams 35b are provided. Although two beams 35b are shown in FIG. 2, three or more beams 35b may be provided, or only one beam 35b may be provided. The beam 35b may be configured integrally with the cab mount reinforcing portion 35a. Of the frame portion 31, the portion where the cab deck reinforcing portion 35 is fixed is higher in rigidity than the portion where the cab deck reinforcing portion 35 is not fixed (a high rigidity portion). The cab deck reinforcing portion 35 does not have to be a plate shape or a rod shape, and may be, for example, a block shape (such as a rectangular parallelepiped shape).

  The support beam 40 (connection beam) is a beam that supports the cab deck 30 with respect to the revolving frame 10. The support beam 40 is connected (fixed) to the revolving frame 10 and the cab deck 30, and more specifically, connected to the second vertical plate 13B and the frame portion 31 (inner side plate 31i). As shown in FIG. 3, the support beam 40 is provided to avoid interference between a cab (not shown) attached to the cab deck 30 and the boom B. More specifically, the boom foot Bf is disposed so as to sandwich the boom mounting bracket 14 from both sides in the lateral direction X. Therefore, it is necessary to leave a space in the lateral direction X between the boom mounting bracket 14 and the cab. Therefore, it is necessary to leave a space in the horizontal direction X between the revolving frame 10 and the cab deck 30, and more specifically, it is necessary to leave a space in the horizontal direction X between the second vertical plate 13B and the inner side plate 31i. is there. In order to leave this space, a support beam 40 is provided. The support beam 40 extends in the lateral direction X. The support beam 40 includes a first support beam 41 and a second support beam 42.

  The first support beam 41 is fixed to the rear Y2 end (or the vicinity thereof) of the inner side plate 31i. As shown in FIG. 4, the first support beam 41 is, for example, solid and may be hollow. The cross section of the first support beam 41 viewed from the lateral direction X is, for example, a polygon, such as a rectangle.

  The second support beam 42 is disposed on the front side Y <b> 1 with respect to the first support beam 41. The second support beam 42 is hollow, for example, and may be solid. The cross section of the second support beam 42 viewed from the lateral direction X is, for example, a polygon, a substantially rectangle, and a pentagon. The cross-sectional shape of the second support beam 42 does not have to be a polygon, and may be a C-shape or a circle (the same applies to the first support beam 41).

The second support beam 42 is arranged so that deformation of the second support beam 42 at the fixed portion (connecting portion, so-called root) to the revolving frame 10 (second vertical plate 13B) shown in FIG. 3 is suppressed. Is done. Specifically, as shown in FIG. 4, the second support beam 42 (at least a part thereof) is disposed so as to overlap the front plate 15 (at least a part thereof) when viewed in the lateral direction X. In other words, the second support beam 42 and the front plate 15 are arranged on the same straight line extending in the lateral direction X.
The second support beam 42 faces the front plate 15 in the lateral direction X through the second vertical plate 13B. More specifically, when viewed from the lateral direction X, the fixing portion of the second support beam 42 to the second vertical plate 13B overlaps the fixing portion of the front plate 15 to the second vertical plate 13B.
Specifically, for example, as shown in FIG. 3, the second support beam 42 is arranged as follows. The front-rear direction Y position of the front Y1 end of the second support beam 42 is the same position (or substantially the same position) as the front-rear Y position of the front Y1 end of the front plate 15. The front-rear direction Y position of the rear Y2 end portion of the second support beam 42 is the same position (or substantially the same position) as the front-rear direction Y position of the rear Y2 end portion of the turning frame reinforcing portion 17. The width of the second support beam 42 in the front-rear direction Y is approximately twice the width of the first support beam 41 in the front-rear direction Y.

The second support beam 42 is arranged so that deformation of the second support beam 42 at the fixing portion to the cab deck 30 (inner side plate 31i) is suppressed. The second support beam 42 is fixed to a highly rigid portion of the cab deck 30. Specifically, the second support beam 42 (at least a part thereof) is disposed so as to overlap with the cab deck reinforcing portion 35 (at least a part thereof) when viewed in the lateral direction X. In other words, the second support beam 42 and the cab deck reinforcing portion 35 are arranged in the same straight line extending in the lateral direction X.
The second support beam 42 faces the cab deck reinforcing portion 35 via the inner side plate 31i. More specifically, when viewed from the lateral direction X, the fixing portion of the second support beam 42 to the inner side plate 31i overlaps with the fixing portion of the cab deck reinforcing portion 35 to the inner side plate 31i.
Specifically, for example, the second support beam 42 is arranged as follows. When viewed from the lateral direction X, the second support beam 42 is disposed so as to overlap with a cab mount reinforcing portion 35a (may be a beam 35b) for reinforcing the cab mount 33a. More specifically, when viewed from the lateral direction X, the fixing portion of the second support beam 42 to the inner side plate 31i overlaps with the fixing portion of the cab mount reinforcing portion 35a (or the beam 35b) to the inner side plate 31i. Be placed.

(Modification)
With reference to FIG. 5, the difference with the said embodiment (refer FIG. 3) is demonstrated about the upper turning body 201 of a modification. The width in the front-rear direction Y of the second support beam 242 of the upper swing body 201 is half of the width in the front-rear direction Y of the second support beam 42 (see FIG. 3) of the above embodiment. The position of the rear Y2 end portion of the second support beam 242 is the front side Y1 with respect to the position of the rear Y2 end portion of the second support beam 42 (see FIG. 3) of the above-described embodiment. It is the front side Y1 rather than the rear side Y2 end. In addition, about the other structure of the upper turning body 201, it is the same as that of the upper turning body 1 (refer FIG. 3).

(Comparison)
The vibrations of the cab deck 30 were compared for various upper swing bodies. The upper swing body compared is the upper swing body 1 (model 1) shown in FIG. 3, the upper swing body 201 (model 2) shown in FIG. 5, and the upper swing body 301 (model 3) of the comparative example shown in FIG. And the upper swing body 401 (model 4) of the comparative example shown in FIG.

  The difference between the upper swing body 301 (see FIG. 6) of the comparative example and the upper swing body 201 (see FIG. 5) is as follows. As shown in FIG. 6, the second support beam 342 of the upper swing body 301 does not overlap the front plate 15 when viewed from the lateral direction X. Specifically, the front Y1 end of the second support beam 342 is disposed on the rear Y2 with respect to the rear Y2 end of the front plate 15. The front-rear direction Y position of the rear side Y2 end of the second support beam 342 is the same as the front-rear direction Y position of the rear side Y2 end of the turning frame reinforcing portion 17.

  The difference between the upper swing body 401 (see FIG. 7) of the comparative example and the upper swing body 201 (see FIG. 5) is as follows. As shown in FIG. 7, the upper swing body 401 includes a support beam 442 and a support beam 443 instead of the second support beam 242 (see FIG. 5). The support beam 442 and the support beam 443 do not overlap the front plate 15 when viewed from the lateral direction X. Specifically, the front side Y1 end portion of the support beam 442 is disposed on the rear side Y2 with respect to the rear side Y2 end portion of the front plate 15, and is located on the rear side Y2 with respect to the rear side Y2 end portion of the turning frame reinforcing portion 17. Be placed. The rear Y2 end of the support beam 443 is disposed on the front Y1 with respect to the front Y1 end of the front plate 15.

  The second support beam 242 (see FIG. 5) shown in FIG. 5, the second support beam 342 (see FIG. 6) shown in FIG. 6, the support beam 442 (see FIG. 7) shown in FIG. The width in the direction Y is the same. Further, the width in the front-rear direction Y of the second support beam 42 (see FIG. 3) shown in FIG. 3 is twice the width in the front-rear direction Y of the support beam 442 shown in FIG. It can be said that the second support beam 42 shown in FIG. 3 is a combination of the support beam 442 and the support beam 443 shown in FIG. The width in the vertical direction Z of each support beam was unified.

  The models 1 to 4 were subjected to frequency response analysis, and the response acceleration in the vertical direction Z (at the laterally outer side X2 end and the front side Y1 end) at the right front of the cab deck 30 shown in FIG. 3 and the like was calculated. And the response acceleration in vibration reduction object frequency (about 14 Hz) was compared about models 1-4. The details of the vibration reduction target frequency are as follows. The engine deck 20 and the cab deck 30 shown in FIG. 3 are separated in the front-rear direction Y. Therefore, among various vibration modes of the cab deck 30, as shown in FIG. 8, the vibration mode in which the cab deck 30 is deformed in the vertical direction Z while being deformed in the horizontal direction X is different from the other vibration modes. Become dominant. The frequency of vibration of the cab deck 30 in the vibration mode as shown in FIG. 8 is the vibration reduction target frequency. In the present embodiment and the modification, the vibration reduction target frequency is about 14 Hz. Table 1 shows the reduction rate of the response acceleration at the vibration reduction target frequency when comparing each of the models 1 to 3 with the model 4 (see FIG. 7).

  In model 1 (upper swing body 1 shown in FIG. 3), the response acceleration at the vibration reduction target frequency was reduced (decreased) by about 72% compared to model 4 (upper swing body 401 shown in FIG. 7). In Model 1, the response acceleration near 40 Hz was reduced by about 82% compared to Model 4 (not shown in Table 1). Although the sum of the widths in the front-rear direction Y of the support beam 40 of the model 1 is the same as the sum of the widths in the front-rear direction Y of the support beams (the first support beam 41 and the support beams 442, 443) of the model 4. In contrast, in model 1, the response acceleration at the vibration reduction target frequency or the like was reduced as compared with model 4.

  In model 2 (upper turning body 201 shown in FIG. 5), the response acceleration at the vibration reduction target frequency was reduced by about 19% compared to model 4 (see FIG. 7). Although the total width of the support beams 40 of the model 2 in the front-rear direction Y is smaller than the total of the widths of the support beams Y of the model 4 in the front-rear direction Y (about 2/3), Compared with, the response acceleration at the vibration reduction target frequency was reduced. Further, comparing Model 2 and Model 1 (see FIG. 3), it can be seen that the response acceleration decreases as the width of the support beam 40 in the front-rear direction Y increases.

  In model 3 (the upper-part turning body 301 of the comparative example shown in FIG. 6), the response acceleration at the vibration reduction target frequency increased by about 40% compared to model 4 (see FIG. 7).

(Effect 1)
The effects of the upper swing body 1 shown in FIG. 1 are as follows.
The upper swing body 1 includes a swing frame 10, an engine deck 20, a cab deck 30, and a second support beam 42 (support beam 40). The revolving frame 10 has a front plate 15 that connects the vertical plates 13 facing in the lateral direction X. The engine deck 20 is disposed on the outer side X <b> 2 in the lateral direction from the revolving frame 10 and is fixed to the revolving frame 10. The cab deck 30 is disposed on the front side Y1 with respect to the engine deck 20 with a gap S between the cab deck 30 and the engine deck 20. The second support beam 42 is connected to the revolving frame 10 and the cab deck 30.
[Configuration 1] As shown in FIG. 4, the second support beam 42 is disposed so as to overlap the front plate 15 when viewed in the lateral direction X.

Due to the above [Configuration 1], the second support beam 42 shown in FIG. 1 is fixed to the revolving frame 10 at a portion having high rigidity as compared with the case where the above [Configuration 1] is not provided. Therefore, deformation of the second support beam 42 is suppressed. Therefore, the vibration of the cab deck 30 to which the second support beam 42 is fixed can be suppressed. Specifically, for example, the vibration that the cab deck 30 is deformed in the vertical direction Z while being deformed in the horizontal direction X can be suppressed. As a result, vibration in the cab attached to the cab deck 30 can be suppressed.
In addition, the effect of suppressing the vibration of the cab deck 30 can be obtained without significantly increasing the mass of the support beam 40 with respect to the conventional upper swing body. For example, the vibration of the cab deck 30 can be suppressed even when the mass of the support beam 40 is the same or smaller than that of the conventional upper-part turning body (see the comparison between the above embodiment and the comparative example). Therefore, although the vibration of the cab deck 30 can be suppressed, the mass of the support beam 40 can be suppressed. As a result of suppressing the mass of the support beam 40, the mass of the upper swing body 1 can be suppressed, and the cost of the upper swing body 1 can be suppressed.

(Effect 2)
As shown in FIG. 2, the cab deck 30 includes a frame portion 31 to which the second support beam 42 (support beam 40) is fixed, and a cab deck reinforcing portion 35 to be fixed to the frame portion 31.
[Configuration 2] The second support beam 42 is disposed so as to overlap the cab deck reinforcing portion 35 when viewed in the lateral direction X.

  With the above [Configuration 2], the second support beam 42 is fixed to the cab deck 30 at a portion having higher rigidity than in the case where the [Configuration 2] is not provided. Therefore, deformation of the second support beam 42 is suppressed. Therefore, the vibration of the cab deck 30 to which the second support beam 42 is fixed can be further suppressed.

(Other variations)
The above embodiment (and variations thereof) may be variously modified.
Some of the components of the above embodiment may not be provided. For example, the turning frame reinforcing portion 17 shown in FIG. 3 may not be provided.
The shape of each component may be changed as appropriate. For example, the shape of the support beam 40 may be changed as appropriate.
In the above embodiment, two vertical plates 13 shown in FIG. 1 are provided and fixed to both ends (or substantially both ends) of the laterally outer side X2 of the bottom plate 11. However, the number and arrangement of the vertical plates 13 may be changed. For example, more than two vertical plates 13 may be provided, and a plurality of vertical plates 13 may be provided on one side and the other side in the lateral direction X with respect to the center line 10c.
In the above embodiment, two support beams 40 are provided, but three or more support beams 40 may be provided.
In the above embodiment, the second support beam 42 shown in FIG. 3 is disposed at a position overlapping the cab mount reinforcing portion 35a when viewed from the lateral direction X. However, the second support beam 42 may be disposed at a position overlapping the cab deck reinforcing portion 35 other than the cab mount reinforcing portion 35a when viewed from the lateral direction X, and the cab deck reinforcing portion 35 when viewed from the lateral direction X. You may arrange | position in the position which does not overlap with.

DESCRIPTION OF SYMBOLS 1,101 Upper turning body 10 Turning frame 13 Vertical board 15 Front board 20 Engine deck 30 Cab deck 31 Frame part 40 Support beam 42, 142 2nd support beam S Gap

Claims (2)

A swivel frame having a front plate connecting the vertical plates facing each other in the lateral direction;
An engine deck that is disposed laterally outside the swivel frame and is fixed to the swivel frame;
A cab deck than with a gap the engine deck is disposed on the front side, Ru is disposed laterally outward from the rotating frame with a gap between the rotating frame between the engine deck,
A support beam connected to the swivel frame and the cab deck;
With
The support beam is disposed so as to overlap the front plate as viewed from the side ,
The laterally outer end of the support beam is directly connected to the laterally inner portion of the cab deck.
The upper turning body of construction machinery. An upper swing body of the construction machine according to claim 1,
The cab deck is
A frame portion to which the support beam is fixed;
A cab deck reinforcing portion fixed to the frame portion;
With
The support beam is disposed so as to overlap the cab deck reinforcing portion as viewed from the side.
The upper turning body of construction machinery.