JP2011111103A - Vibration control cabin type working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration control cabin type working vehicle improving a working environment under the load of noises while making the best use of a vibration control effect by reducing uncomfortable noises affecting ears of an operator in a specified condition. <P>SOLUTION: In the vibration control cabin type working vehicle, a cabin (5) with an operator's seat (16), on which an operator is seated for operating various types of equipment, is supported in a vehicle underframe in a vibration isolating manner. Moreover, the vibration control cabin type working vehicle includes vehicle constituting equipment exerting noises asymmetrically to the cabin (5). On the right and left sides of the cabin (5), right and left sound absorption parts (17, 17) absorbing the noises in the cabin (5) are formed so as to face the operator's seat (16). Both of the sound absorption parts (17, 17) are set to have a difference in sound absorption characteristics equivalent to a difference in right and left sound pressure of the noises due to a specified asymmetrical sound pressure distribution. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vibration-proof cabin type work vehicle in which a cabin including a control seat for an operator is vibration-proofed and supported by a vehicle underframe.

  As shown in Patent Document 1, a cabin-equipped work vehicle is known in which a sound-absorbing material is formed by providing a sound-absorbing material in an opening of an interior surface of a cabin. In this work vehicle, sound absorbing portions are formed symmetrically on both side surfaces of the cabin, and noise in the cabin can be reduced by the same sound absorbing characteristics as the left and right while harmonizing with the interior material.

JP 2008-260432 A

  However, even if the cabin is configured symmetrically in the center of the fuselage of the work vehicle, the control seat is arranged in the center of the cabin, and the sound absorbing portion is configured symmetrically in the interior of the cabin, the left and right noise can be reduced. In certain conditions due to fluctuations in travel speed, work content, etc., residual noise may act on the operator's ear in the cabin, and the discomfort of the residual noise acting on the ear cannot be eliminated, especially In an anti-vibration cabin type work vehicle that improves the working environment by supporting the cabin on the vehicle frame to prevent vibrations, the anti-vibration effect cannot be fully utilized and the residual noise at the ears may be increased. Measures to solve such problems have been awaited.

  An object of the present invention is to provide an anti-vibration cabin type work that can improve the working environment under a noise load by taking advantage of the anti-vibration effect by reducing unpleasant residual noise that acts on the operator's ears under specific conditions. To provide a vehicle.

  According to a first aspect of the present invention, there is provided a vehicle component device that provides anti-vibration support to a vehicle underframe for a cabin having a control seat for an operator to sit on and operate various devices, and that causes noise asymmetrically to the cabin. The left and right sides of the cabin are formed with left and right sound absorbing parts that absorb noise in the cabin facing the control seat, and these two sound absorbing parts have specific sound pressures that are asymmetrical to the left and right. It is characterized in that a sound absorption characteristic difference corresponding to a sound pressure difference between left and right noises due to distribution is set.

  Sound absorbing parts are formed on both the left and right sides of the cabin facing the control seat, and these sound absorbing parts are set to have left and right sound absorbing performance according to a specific sound pressure distribution. When noise with a specific sound pressure distribution that is asymmetrical to the left and right acts by the noise source device in the cabin, the sound is silenced by the sound absorption performance corresponding to the sound pressure difference between the left and right.

According to a second aspect of the present invention, in the configuration of the first aspect, the sound absorbing portion includes a perforated plate that is exposed in the cabin and has a plurality of through holes, a sound absorbing material that covers a back surface thereof, and the sound absorbing material. It is characterized by comprising a back air layer for silencing defined on the back side of the sound.
Since the sound absorbing part is composed of a perforated plate, a sound absorbing material, and a back air layer, different sound absorbing characteristics are secured on the left and right depending on the difference in any of the aspects.

  In the work vehicle according to the first aspect of the present invention, sound absorbing portions are formed on both the left and right sides of the cabin facing the control seat, and these sound absorbing portions are specified as left and right asymmetry on the left and right sides of the operator of the control seat. The sound absorption performance corresponding to the sound pressure distribution of the vehicle makes it possible to eliminate the left-right difference of the operator's ear noise based on the left-right asymmetry in the vehicle configuration, especially for the cabin that is supported by vibration isolation on the vehicle underframe. When specific noise from the noise source device acts asymmetrically in the left-right direction, it will not be bothered by specific left-right asymmetrical unpleasant noise that cannot be eliminated by the symmetrical sound absorption part. This makes it possible to improve the working environment for the operator in the cabin.

  In other words, due to restrictions on equipment arrangement due to equipment configuration and airframe configuration, the construction of the work vehicle must be left-right asymmetric, and as a result, noise strongly acts asymmetrically on the cabin depending on the work conditions. Therefore, even if noise is reduced equally on the left and right sides, in particular, in a vibration-proof cabin type work vehicle that improves the work environment by supporting the cabin on the vehicle frame to prevent vibration, a specific sound pressure in the cabin Depending on the distribution, certain large ear noises that are biased to the left and right may remain, and it has been found from the results of noise analysis that this ear residual noise causes discomfort to the operator. By setting the sound absorbing characteristics to the left and right sound absorbing portions, it is possible to reduce the discomfort experienced by the operator.

  In addition to the effect of the first aspect, the work vehicle according to the second aspect of the present invention has the sound absorbing portion (17) according to any one of the modes of the perforated plate (23), the sound absorbing material (24), and the back air layer (A). Depending on the difference, it is possible to easily set different sound absorption characteristics on the left and right.

Side view of a tractor as an application example of the present invention Expanded perspective view of the main part of the cabin Cross section of the main part of the pillar A perspective view of the cabin front Outline drawing of main part of cabin (a) and enlarged cross-sectional view of fender part (b) Expanded perspective view of main part of cabin having oval sound absorption part Longitudinal sectional views of structural example 1 (a) and structural example 2 (b) of the sound absorbing portion of the roof inner Outline drawing of cabin interior of tractor Cross section of main part of air column resonance sound absorption mechanism Aircraft side view showing cabin floor configuration Plan view of configuration example of cabin floor Enlarged cross-sectional view of sound-absorbing material by resonance sound-absorbing mechanism Plan view of another cabin floor configuration example Enlarged sectional view of sound-absorbing material with partition plate Plan view of another cabin floor configuration example Expanded sectional view of sound absorbing material with multilayer structure

Embodiments specifically configured based on the above technical idea will be described below with reference to the drawings.
FIG. 1 is a side view of a tractor as an application example of the present invention.
The tractor 1 supports a cabin 5 having a box shape on an underframe 4 supported by left and right front and rear wheels 2, 2, 3, 3 so as to be able to travel on a farm field by means of an elastic support bracket (not shown). , The transmission 6 that shifts the power from the engine 6 and transmits it to the left and right front and rear wheels 2, 2, 3, and 3, and the PTO that branches and outputs the power from the transmission 7 A lifting hitch 8 or the like that connects the traction work machine so that it can be lifted is mounted on the underframe 4.

  The cabin 5 includes a roof 11 that covers and closes the top, a front window 12 for securing a front view, a rear window 13 for securing a rear view, and left and right doors 14b and 14b capable of securing a side view. And left and right rear side windows 14c, 14c. Left and right center pillars 14a are formed between the left and right doors 14b and 14b and the left and right rear side windows 14c and 14c. The bottom of the cabin 5 is closed by a step (bottom plate) 15 and a control seat 16 is arranged. Further, the roof 11 is supported by left and right front pillars 12a and 12a at both ends of the front window 12, left and right rear pillars 13a and 13a at both ends of the rear window 13, and the left and right center pillars 14a.

  2, the left and right center pillars 14a and 14a and the left and right rear pillars 13a and 13a are provided with sound absorbing portions 17 and 18 having specific sound absorbing characteristics, respectively. . You may provide in right-and-left front pillar 12a, 12a. Moreover, you may comprise so that it may provide in the right and left of the said roof 11. FIG.

  Each pillar 12a-14a is comprised by the vertical frame 21 of the U-shaped cross section opened to a vehicle interior, as shown to the principal part sectional drawing of FIG. A cover 22 for interior is attached to the vertical frame 21, and an opening is formed in a part of the cover 22 to form a recess that faces the control seat 16 and opens in the interior surface. The perforated plate 23 in which the through holes are formed is provided integrally with the cover 22 or separately, and the sound absorbing material 24 is supported on the back side of the perforated plate 23 to close the opening of the recessed portion. The sound absorbing portions 17 and 18 are formed by defining a rear air layer A for noise reduction on the back side.

  The perforated plate 23 and the sound absorbing material 24 can be individually changed as sound absorbing characteristic setting means of the sound absorbing portions 17 and 18 having such a configuration. Specifically, the shape and material of the opening area of the cover 22, the opening pitch of the holes of the porous plate 23, the hole diameter, the number of holes, the opening ratio, etc., the thickness of the sound absorbing material 24, the porosity, the multilayer combination, etc. can be selected. By disposing the specific frequency noise that characterizes the difference between the left and right ear noise values and balancing the left and right, it is possible to effectively eliminate the discomfort given to the operator.

  The sound absorption characteristic setting means includes various devices that act on the operator of the control seat 16 asymmetrically from the left and right asymmetry due to restrictions on the device configuration and the device configuration accompanying the airframe configuration, such as an engine in a tractor, an exhaust muffler, a hydraulic device, A characteristic setting range within a range capable of dealing with noise and vibration generated from the transmission and operating levers connected to the transmission is secured.

  Among the noise generating sources, as shown in the perspective view of the front portion of the cabin in FIG. 4, in order to ensure the front muffler 31 and the exhaust muffler 31 communicating with the engine 6 having a wide rotational speed range at the front portion of the cabin 5. The tail pipe 32 that rises in contact with the pillar 12a may cause a difference in left and right ranging from 1 to 2 db due to a specific sound pressure distribution that varies depending on the work content. Also, the main part of the cabin of FIG. As shown in the sketch (a), the vibrations of the equipment transmitted through the various operation tools arranged in the cabin cause the left-right difference, and in particular, in the enlarged cross-sectional view (b) of the fender portion in FIG. As shown in the figure, the specific vibration transmitted by the lifting / lowering operation position of the work implement lifting / lowering operation lever 34 supported by the fender 33 which is a cabin component on the side of the control seat 16 causes the difference between left and right. 5 may cause noise that is unevenly distributed on one side, and may also generate unevenly distributed noise from the hydraulic equipment that is grounded below the components of the cabin 5. A wide characteristic range can be set so as to be able to cope with specific noise acting on

  The work vehicle having the above configuration faces the control seat 16 and forms sound absorbing portions 17 and 18 on the left and right sides of the cabin 5, respectively. The sound absorbing portions 17 and 18 are porous as sound absorbing characteristic setting means on the left and right, respectively. The sound absorption performance of each side can be individually set by the plate 23, the sound absorbing material 24, and the back air layer A, so that a specific anti-vibration-supported cabin 5 based on the left-right asymmetry in the vehicle configuration is specified. When noise acts, it is possible to eliminate left and right differences in specific ear noise acting on the operator seated on the control seat 16 by setting the sound absorption characteristics on each side. While taking advantage of the characteristics of the vehicle, it will not be bothered by unpleasant specific one-side residual noise, and as a result, the working environment in the cabin can be effectively improved

(Cabin roof)
Next, the example which comprises a sound absorption part in the cabin roof 11 is demonstrated. In this case, the left and right sound absorbing portions are configured on the roof inner side of the cabin roof 11 so as to face the vicinity of the head of the operator seated on the control seat 16 so that the sound absorption characteristics can be individually set at the left and right positions. Specifically, the sound absorbing portions are individually configured by separating the left and right by the same left and right circular openings formed in the roof inner, and as shown in the exploded perspective view of the main part of the cabin in FIG. The sound absorbing portion 41 is configured so that the left and right sound absorbing characteristics can be individually set by an oval opening extending left and right.

  As shown in the longitudinal sectional view (a) of the configuration example 1 in FIG. 7, the internal structure is provided with a porous plate 43 integrally or separately in an oblong opening formed on the roof inner member 42 extending left and right. The sound absorbing material 44 is supported on the back surface, and the perforated plate 43 has large opening ratio portions 43a and 43b having large through-hole opening ratios at the left and right end portions, and a small opening ratio portion 43c having a small or non-porous opening ratio at the center portion. As described above, the ranges of the left and right large aperture ratio portions 43a and 43b are individually set on the left and right, or the sound absorption characteristics such as the hole diameter, the thickness of the sound absorbing material 44, and the porosity are individually set on the left and right sides. The effect similar to the above can be obtained by dealing with the difference between the left and right noises. In addition, as shown in the longitudinal sectional view (b) of the configuration example 2 in FIG. 7, the left and right sound absorbing materials 44a and 44b are configured so as to individually set the thickness so as to cover the left and right large aperture ratio portions 43a and 43b. Thus, the same effect as described above can be obtained.

(Air column resonance sound absorption mechanism)
Next, a configuration example by the air column resonance sound absorbing mechanism will be described.
As shown in the interior view of the cabin interior of the tractor in FIG. As shown in the cross-sectional view of the main part of FIG. 9, the sound absorbing portion 51 by the air column resonance sound absorbing mechanism is configured by defining a closed cavity portion C communicating with the small hole B opened to the indoor side in the interior portion. In the sound absorbing portion 51, when sound waves enter the small holes B from the indoor side, the air in the small holes B vibrates, and the air in the closed cavity C repeats compression and expansion, and the sound waves are generated by the viscous resistance of the wall surface during the period The sound absorption characteristics are determined by the area and height of the small hole B, the roughness of the wall surface of the small hole B, the capacity of the closed cavity C, and the sound absorption performance inside. It is possible to set sound absorption characteristics over a wide range by changing.

  In this way, the same effect as described above can be obtained by individually setting the sound absorption characteristics of the left and right sound absorbing portions 51, 51 of the interior portion of the rear fender. Further, the same effect as described above can be obtained including the case where the left and right sound absorbing portions 52, 52 are provided in the roof inner portion and further provided in the center pillar and the rear pillar.

(Cabin floor)
Next, the example which comprises a sound absorption part in a cabin floor is demonstrated.
As shown in the side view of the airframe representing the floor configuration of FIG. 10, the cabin is provided with a sound absorbing material 61 capable of setting sound absorbing characteristics and a floor mat 62 superimposed on the foot plate of the bottom plate 15 constituting the floor. The sound absorption characteristics of the sound absorbing material 61 are divided into left and right so that the setting can be changed.

  Specifically, as shown in the plan view of the example of FIG. 11, the sound absorbing material 61 is formed with two sound absorbing portions 63 and 63, and these two sound absorbing portions 63 and 63 are connected to the center of the cabin floor. The line D is divided into left and right parts and arranged on the bottom plate 15, and a floor mat 62 is provided on top of the line D.

  As shown in the enlarged cross-sectional view of the sound absorbing material by the resonance sound absorbing mechanism in FIG. 12, each sound absorbing portion 63 of the sound absorbing material 61 is configured in three layers by the sound absorbing plates of the lower layer 61a, the middle layer 61b, and the upper layer 61c. A resonance sound absorbing mechanism is formed by forming a large-diameter circular hole that becomes a hollow portion F concentric with the small-diameter circular hole E in the small-diameter circular hole E and the middle layer 61b. A lower layer 61 a side of the sound absorbing material 61 is in contact with the bottom plate 15, a floor mat 62 is stacked on the upper layer 61 c side, and a sound insulating material 64 is interposed below the floor mat 62 as necessary.

  By configuring the cabin floor with the sound absorbing material 61, the approach noise from the bottom plate 15 which is the bottom structural member of the cabin 5 is absorbed by the left and right sound absorbing portions 63, 63, and the volume of the small-diameter circular hole E and the cavity F is reduced. Is set separately for left and right, and each sound absorption characteristic is made to correspond to the frequency of the left and right approaching noise, so that the vibration of the floor board is suppressed to the left and right equally by the additional mass body at the left and right symmetrical position described in JP-A-2008-265374 The difference between the left and right noises that cannot be eliminated depending on the technology can be removed, so that operator discomfort can be reduced.

  Further, the cabin floor by another sound absorbing material 65 will be described. As shown in the plan view of the configuration example of FIG. 13, the sound absorbing material 65 is formed with a plurality of sound absorbing portions 66. The center line D of the cabin floor is divided into left and right parts and arranged on the bottom plate 15, and a floor mat 62 is provided thereon.

  As shown in the enlarged sectional view of the sound absorbing material by the partition plate in FIG. 14, each sound absorbing portion 66 of the sound absorbing material 65 is configured in three layers by upper and lower sound absorbing plates 65a and 65a and an intermediate partition plate 65b. A circular plate G is formed in 65b to constitute a partition plate sound absorbing mechanism with holes. The sound absorbing material 65 is in contact with the bottom plate 15, and a floor mat 62 is stacked on the side, and a sound insulating material 64 is provided below the floor mat 62 as necessary.

  By constituting the cabin floor with the sound absorbing material 65, the approach noise from the bottom plate 15 which is the bottom structural member of the cabin 5 is absorbed by the left and right sound absorbing portions 66, and the volume of the small diameter circular hole E and the cavity portion F is increased. By separately setting the left and right and making each sound absorption characteristic correspond to the frequency of the left and right approach noise, the difference between the left and right of the approach noise can be removed, so that the operator's discomfort can be reduced.

  Further, the cabin floor by another sound absorbing material 67 will be described. As shown in the plan view of the configuration example of FIG. 15, the left and right sound absorbing materials 67 and 67 are both left and right with respect to the center line D of the cabin floor as a sound absorbing portion. The floor mat 62 is placed on the bottom plate 15, and a sound insulating material 64 is provided below the floor mat 62 as necessary.

  As shown in the enlarged sectional view of the sound-absorbing material having a multilayer structure in FIG. 16, the sound-absorbing material 67 is configured in three layers by upper and lower sound-absorbing plates 67a and 67a and an intermediate adhesive layer 67b. By configuring the cabin floor with the sound absorbing material 67, the approach noise from the bottom plate 15 which is the bottom structural member of the cabin 5 is absorbed by the left and right sound absorbing materials 67, 67, and the characteristic value (bulk) regarding the ventilation performance of the sound absorbing plate 67a. (Density, porosity, number of stacks) are set separately for the left and right, and each sound absorption characteristic corresponds to the frequency of the left and right approach noise, so that the difference between the left and right of the approach noise can be eliminated. Can be reduced.

1 Tractor (Anti-vibration cabin type work vehicle)
4 frame 5 cabin 11 cabin roof 12 front window 12a front pillar 13 rear window 13a rear pillar 14a center pillar 14b door 14c side window 15 bottom plate 16 control seat 17 sound absorbing portion 18 sound absorbing portion 21 vertical frame 22 cover 23 porous plate 24 sound absorbing material 41 Sound absorbing portion 42 Roof inner member 44 Sound absorbing material 44a Sound absorbing material 44b Sound absorbing material 51 Sound absorbing portion 52 Sound absorbing portion 61 Sound absorbing material 61a Lower layer 61b Middle layer 61c Upper layer 62 Floor mat 63 Sound absorbing portion 64 Sound insulating material 65 Sound absorbing material 65a Sound absorbing plate 65b Sound absorbing plate 65b Part 67 Sound absorbing material 67a Sound absorbing plate 67b Adhesive layer A Back air layer B Small hole C Closed cavity part D Center line E Small diameter circular hole F Cavity part G Circular hole

Claims (2)

A vehicle configuration in which a cabin (5) including a control seat (16) for an operator to sit on and operate various devices is supported by vibration isolation on a vehicle underframe and noise is asymmetrically applied to the cabin (5). In a vibration-proof cabin type work vehicle equipped with equipment,
Left and right sound absorbing portions (17, 17) for absorbing noise in the cabin (5) are formed on the left and right sides of the cabin (5) so as to face the control seat (16), and both the sound absorbing portions (17, 17) An anti-vibration cabin type work vehicle characterized by setting a sound absorption characteristic difference corresponding to a sound pressure difference between left and right noises due to a specific sound pressure distribution that is asymmetric left and right.   The sound absorbing portion (17) includes a perforated plate (23) exposed in the cabin (5) to form a plurality of through holes, a sound absorbing material (24) covering the back side thereof, and the sound absorbing material (24). The anti-vibration cabin type work vehicle according to claim 1, comprising a rear air layer (A) for noise reduction defined on the rear side of the vehicle.

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