JP4897641B2 - Bolt fastening structure and construction machinery - Google Patents

Description

  The present invention relates to a bolting structure in which a plurality of plates are overlapped and fixed with bolts, and a construction machine adopting the bolting structure. In particular, the present invention relates to a configuration in which a space between an inner peripheral surface of a through hole for passing a bolt formed on each of the plurality of plates and an outer peripheral surface of the bolt is sealed.

  Conventionally, this type of bolting structure has been adopted as a structure for fixing an air conditioning unit (hereinafter simply referred to as an air conditioning unit) to a cab of a construction machine. In this case, the bolt tightening structure is required to have high strength so that it can withstand the weight of the air conditioning unit and the vibration while the vehicle is running. Moreover, a waterproof function is required so that rainwater or the like does not enter the cab through the hole through which the bolt of the bolt tightening structure is inserted.

  On the other hand, as conventional bolt fastening structures, for example, structures disclosed in Patent Document 1 and Patent Document 2 have been proposed. In this conventional structure, as shown in FIG. 7, a plurality of plates 41, 42 are arranged in an overlapping manner, and through holes 41 a, 42 a are formed in these plates 41, 42. Bolts 44 are inserted into the through holes 41 a and 42 a of both plates 41 and 42 through washers 43, and nuts 45 as female screws are screwed into the ends of the bolts 44. Ring grooves 43a and 43b are formed on both side surfaces of the washer 43, and seal rings 46 and 47 are disposed in the ring grooves 43a and 43b.

Then, the bolts 44 and the nuts 45 are screwed together, whereby the plates 41 and 42 are fastened and fixed in a superposed state between the washer 43 and the nut 45 on the head side of the bolts 44. In this case, one seal ring 46 seals between the head 44 a of the bolt 44 and the washer 43, and the other seal ring 47 seals between the washer 43 and the corresponding plate 41. As a result, even if water enters the gap between the outer peripheral surface of the bolt 44 and the inner peripheral surface of the through holes 41a and 42a, it is blocked by the seal rings 46 and 47. For this reason, the water is prevented from flowing down to the lower side of FIG. 7 through between the bolt head 44a and the washer 43.
Japanese Utility Model Publication No. 56-117113 Japanese Utility Model Publication No. 5-3625

  However, as described above, in this conventional bolting structure, the seal rings 46 and 47 are disposed in the annular grooves 43 a and 43 b on both side surfaces of the washer 43, and accordingly, the seal rings 46 are disposed on both side surfaces of the washer 43. , 47 annular grooves 43a, 43b are formed. For this reason, compared with the bolt fastening structure which does not arrange | position the seal rings 46 and 47, the contact area of the metals between the head 44a of the bolt 44 and the washer 43 reduces. For this reason, there is a problem that a strong tightening axial force cannot be secured between the bolt 44 and the nut 45, and anxiety remains in terms of tightening strength with respect to both the plates 41 and 42. That is, in this conventional bolt tightening structure, when a strong tightening torque is applied between the bolt 44 and the nut 45 in order to ensure the tightening strength, the pressure rises and the head 44a or washer of the bolt 44 is increased. 43 may be damaged. In order to prevent this, it is possible to use a bolt with a large head and a correspondingly large diameter washer. For this purpose, it is not a general purpose ISO (International Standard). Special bolts and washers must be used, losing versatility in the market and unavoidably increasing costs.

  The present invention has been made paying attention to such problems existing in the prior art. The purpose is to secure a wide metal contact area between the bolt head and the washer, so that the plate between the bolt and nut can be strongly tightened, and water can enter from the bolt tightening part. An object of the present invention is to provide a bolt tightening structure that can be suppressed and that can use general-purpose bolts and washers.

In order to achieve the above-mentioned object, the present invention is configured such that a plurality of plates are overlapped, a bolt is passed through a through hole formed in the plate, and the bolt is screwed into a female screw. In the bolt tightening structure that fixes each other and seals between the outer peripheral surface of the bolt and the inner peripheral surface of the through hole, a washer is provided between the head of the bolt and the plate on the head side. and a collar is interposed, it is interposed a seal ring and between the outer periphery of the collar and the bolt of the collar and the plate.

Particularly in this invention, the washer is disposed on the head side of the bolt, the collar is disposed on the plate side, the seal ring is disposed between the outer peripheral edge of the collar and the plate, and the collar. And a second seal ring interposed between the inner peripheral edge of the bolt and the outer peripheral surface of the non-threaded portion of the bolt, and the seal ring is not disposed between the head of the bolt and the washer. It is said .

Further, in the configuration described above, the side walls of the construction machine cab, an air conditioning unit that penetrates the inside and outside of the side wall is provided, the lower portion of the cab interior side of the air conditioning unit bolting structure according to claim 1 It is preferable to employ this structure.

  In the bolt tightening structure of the present invention, since there is no seal ring between the head of the bolt and the washer, a wide contact area between metals can be ensured between them. Therefore, even when the bolt is tightened with a strong tightening force, there is no risk of damage to the head of the bolt, the washer, or the like, and a plurality of plates can be fastened and fixed with a bolt and a nut with a strong tightening force. Therefore, it is not necessary to increase the diameter of the bolt head or washer. In addition, since a pair of seal rings seals between the collar and the plate and between the collar and the outer periphery of the bolt, even if water enters between the inner peripheral surface of the through hole and the outer peripheral surface of the bolt, Water never comes out on the head side of the bolt.

  As described above, according to the present invention, the plate can be fastened and fixed with a strong fastening force, water can be prevented from entering from the bolt fastening portion, and general-purpose parts can be used. The effect that the cost can be reduced is exhibited.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, in the bulldozer as a construction machine of this embodiment, a cab 11 is supported on a vehicle body frame 12 via a plurality of dampers 13.

  As shown in FIGS. 1 to 3, the unit frame 15 of the air conditioning unit 14 is attached to the upper end of the rear wall portion of the cab 11 and penetrates the inside and outside of the rear wall portion. As a result, the amount of the air conditioning unit 14 projecting outside the cab 11 is suppressed. The air blowout port 16 and the air intake port 17 are formed in the upper part and the lower part of the front surface of the unit frame 15 so as to open in the cab 11. As the air conditioning unit 14 is operated, the air in the cab 11 is taken into the air conditioning unit 14 from the air intake port 17 and the temperature and humidity are adjusted, and then blown out from the air outlet 16 into the cab 11. . A seal 24 is provided between the air blowing port 16 and the air intake port 17 between the outer surface of the cab 11 and the unit frame 15.

Next, the fixing structure of the lower portion of the unit frame 15 of the air conditioning unit 14 with respect to the cab 11 on the cab room side will be described in detail.
As shown in FIGS. 3 and 4, the mounting plate 26 is fixed to a cab frame (not shown) of the cab 11. The cover plate 21 is laminated on the mounting plate 26, the reinforcing plate 23 is laminated on the cover plate 21, and the plates 26, 21, and 23 are fixed by bolts 28 and nuts 27. The cover plate 21 constitutes the lower part of the unit cover 18 shown in FIG. The reinforcing plate 23 is welded and fixed to the upper surface of the front portion of the cover plate 21 of the unit frame 15 to reinforce the unit frame 15.

  The through holes 23 a, 21 a, and 26 a are formed in the reinforcing plates 23, the cover plate 21, and the mounting plate 26 so as to be positioned at a plurality of locations (only one location is shown in the drawing) inside the cab 11. The plurality of nuts 27 as female screws are welded and fixed on the reinforcing plates 23 corresponding to the through holes 23a and the like. The plurality of bolts 28 include a head portion 28a, a neck portion 28b as a non-threaded portion not having a screw, and a threaded portion 28c. The bolt 28 passes through the through holes 26 a, 21 a, and 23 a upward from the inside of the cab 11, and the screw portion 28 c is screwed into the nut 27. The bolts 28 are screwed into the nuts 27 in this way, whereby the reinforcing plate 23 and the cover plate 21 are fastened and fixed on the mounting plate 26 in a superposed state.

  As shown in FIGS. 3 and 4, the metal washer 29 and the collar 30 are interposed between the head 28a of the bolt 28 and the mounting plate 26 adjacent to the head 28a. The stepped recess 30 a is formed on the upper outer periphery of the collar 30. The tapered recess 30 b is formed on the lower inner periphery of the collar 30. The first seal ring 31 made of an elastic material such as rubber is disposed in the stepped recess 30 a of the collar 30 so as to be interposed between the collar 30 and the mounting plate 26. The second seal ring 32 made of an elastic material such as rubber is tapered between the collar 30 and the outer periphery of the neck portion 28b as the non-threaded portion of the bolt 28. 30b.

  Then, as shown in FIG. 5, with the seal rings 31 and 32 disposed in the recesses 30a and 30b of the collar 30, the bolt 28 is passed through the washer 29, the collar 30 and the through holes 26a, 21a and 23a through the nut 27. As shown in FIG. 4, the seal rings 31 and 32 are elastically deformed. By this elastic deformation, the first seal ring 31 is brought into pressure contact with the upper surface of the collar 30 and the lower surface of the mounting plate 26, and the space between them is sealed. At the same time, the second seal ring 32 is brought into pressure contact with the inner peripheral surface of the collar 30 and the outer peripheral surface of the neck portion 28b of the bolt 28, and the space between them is sealed.

  As a result, the space between the outer peripheral surface of the bolt 28 and the inner peripheral surfaces of the through holes 23a, 21a, and 26a is sealed. Therefore, water such as rainwater flows into the unit frame 15 of the air conditioning unit 14 that protrudes from the rear of the cab 11, and the water flows on the outer peripheral surface of the bolt 28 and the inner peripheral surfaces of the through holes 23a, 21a, and 26a. Can be prevented from entering the cab 11 through the gap. By the way, if the air conditioning unit 14 penetrates the inside and outside of the cab 11, when rainwater or water that has washed the vehicle enters the outer periphery of the air conditioning unit 14, the rainwater or the like easily falls into the cab 11. There is no such fear in the form.

  Therefore, in this bolt tightening structure, as described above, the gap between the mounting plate 26 and the collar 30 and the collar 30 and the outer peripheral surface of the bolt 28 are sealed by the seal ring 30.31. It is prevented from falling into the cab 11 through the space between the outer peripheral surface of the bolt 28 and the inner peripheral surface such as the through hole 26a. For this reason, this bolting structure is useful when employed in a configuration provided with an air conditioning unit that penetrates the side wall of the cab 11 as in the embodiment. In this embodiment, unlike the conventional example shown in FIG. 7, the seal ring is not fitted into the grooves on both side surfaces of the washer. Accordingly, a seal ring having a large diameter (cross-sectional diameter) can be used, and a sufficient sealing effect can be obtained.

  Further, the seal rings 31 are arranged above and below the collar 30, and no seal ring exists between the head 28 a of the bolt 28 and the washer 29. For this reason, a wide contact area between metals can be ensured between the head 28 a of the bolt 28 and the washer 29. Therefore, even when the bolt 28 is tightened with a strong tightening force, there is no risk of damage to the head 28a or the washer 29 of the bolt 28, and the reinforcing plate 23, the cover plate 21 and the mounting plate 26 are tightened and fixed with a strong tightening force. can do. For this reason, it is not necessary to use a bolt 28 having a large head 28a or a washer 29 having a large diameter, and a general-purpose one can be used, which is effective for cost reduction.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
As shown in FIG. 6, a ring-shaped groove 30c may be provided on the mounting plate 26 side of the collar 30, and the seal ring 31 may be fitted into the groove 30c.

In the embodiment described above, the nut 27 as a female screw is welded and fixed to the reinforcing plate 23. However, the nut 27 is not necessarily fixed.
In the embodiment, the present invention is embodied in the bolt tightening structure in the case where the unit frame 15 of the air conditioning unit 14 is mounted and fixed to the cab 11 of the construction machine, but the plate-like member in the other part of the construction machine You may embody in the bolting structure or the bolting structure of the plate-shaped member in another machine.

The side view which shows the construction machine provided with the bolting structure of one Embodiment. The principal part perspective view which expands and shows the mounting structure of the air conditioning unit with respect to a cab in the construction machine of FIG. The principal part sectional drawing which similarly shows the mounting structure of an air conditioning unit. The fragmentary sectional view which expands and shows the bolt fastening structure in the mounting structure of the air conditioning unit. Similarly, the fragmentary sectional view which shows the state before the fastening of a bolting structure. The fragmentary sectional view which shows the example of a change. The fragmentary sectional view which shows the conventional bolt fastening structure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Cab, 14 ... Air conditioning unit, 15 ... Unit frame, 21 ... Cover plate, 21a ... Through hole, 23 ... Reinforcement plate, 23a ... Through hole, 24 ... Seal, 26 ... Mounting plate, 26a ... Through hole, 27 ... Nuts as female threads, 28 ... bolts, 28a ... heads, 28b ... neck portions as non-threaded parts, 29 ... washers, 30 ... collars, 31 ... first seal rings, 32 ... second seal rings.

Claims (2)

By overlapping a plurality of plates, passing bolts through the through holes formed in those plates, and screwing the bolts into the female screws, the plates are fixed to each other, and the outer peripheral surface of the bolts are transparent. In the bolt tightening structure that seals between the inner peripheral surface of the hole,
Wherein between the bolt head and its head side of the plate, a washer and a collar is interposed, the sealing ring is interposed between the outer and between collar and bolt between the collar and the plate Rutotomoni,
The washer is disposed on the head side of the bolt, the collar is disposed on the plate side, the seal ring is disposed between the outer peripheral edge of the collar and the plate, and the inner peripheral edge of the collar And a second seal ring interposed between the outer peripheral surface of the non-threaded portion of the bolt,
The bolt tightening structure, wherein the seal ring is not disposed between the head of the bolt and the washer . An air conditioning unit penetrating the inside and outside of the side wall of the cab of the construction machine is provided, and the bolt tightening structure according to claim 1 is adopted as a fixing structure of a lower portion of the air conditioning unit on the cab indoor side. Construction machine characterized by.

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