JP2008265379A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working vehicle enhancing the working environment by reliably absorbing the vertical vibration of a vehicle body to be propagated from the vehicle body to a seat and reducing the vibration of the seat. <P>SOLUTION: A seat for the steering is provided on an upper part of a vehicle body, and a dynamic damper is provided, which comprises an elastic body consisting of a seat pan below the seat and an arm mounted on a stay for supporting the seat on the seat pan substantially parallel to the seat pan and a mass mounted on the stay. The parameter of the dynamic damper is changed so that the natural frequency in the vertical direction of the vehicle body of the dynamic damper is matched with the natural frequency of the entire vehicle body in the vertical direction of the vehicle body. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work vehicle provided with a seat for steering at the upper part of the fuselage, and more specifically, a seat pan at a lower part of the seat and a seat pan on a stay supporting the seat on the seat pan. A dynamic vibration absorber consisting of an elastic body provided between the arms attached in parallel and a mass body attached to the stay is provided, and the natural vibration frequency of the dynamic vibration absorber in the vertical direction of the fuselage is It relates to making it possible to change the parameters of the dynamic vibration absorber so as to match the natural frequency of the direction.

  In a conventional work vehicle, for example, a seat provided in a cabin disposed in the upper center of the fuselage is supported by the airframe in an anti-vibration manner by an air spring in which an air chamber is formed in front, rear, left, and right to have a C shape. In addition to those (Patent Document 1), there are some which are supported by the metal body with vibration prevention by metal springs or the like. However, with only the sheet support by these springs, the low in the vertical direction of the aircraft that is easily felt by humans when the aircraft is running It is difficult to effectively reduce the frequency vibration, so there is also a method of extremely softening the members making up the seat and supporting the seat on the fuselage, but in this case, such as sitting on the seat and stepping on the clutch There was a problem of giving uncomfortable feeling to the operator who performed the operation. In view of this, there is also a type in which a dynamic vibration absorber that generates the same natural frequency as that of the airframe and absorbs vibration propagated from the airframe to the seat by resonance is provided in the lower part of the seat (Patent Document 2).

Japanese Utility Model Publication No. 7-4152 JP 2003-226179 A

However, in the seat of a work vehicle equipped with such a dynamic vibration absorber, for example, when the mass of the entire fuselage changes due to an attachment such as a rotary attached to a tractor, or when the vehicle drive unit is a wheel type, it is installed Because the spring constant of the entire fuselage changes depending on the type of tires used, the natural frequency of the vertical vibration of the entire aircraft will change, so the natural frequency of the vertical vibration of the entire aircraft will change. However, the vibration damping in the vertical direction of the fuselage installed on the seat does not match the preset natural frequency and the vertical vibration transmitted from the fuselage to the seat cannot be absorbed by resonance. There was a problem that the vibration action was significantly reduced.
SUMMARY OF THE INVENTION An object of the present invention is to provide a work vehicle with an improved work environment that can reliably absorb vibrations in the vertical direction of the airframe transmitted from the airframe to the seat to reduce the vibration of the seat.

  For this reason, the invention described in claim 1 is a work vehicle including a steering seat at an upper portion of the fuselage, and the seat pan at the lower portion of the seat and a stay that supports the seat on the seat pan. A dynamic vibration absorber comprising an elastic body provided between a pan and an arm attached substantially in parallel with the mass body attached to the stay; and the natural vibration frequency of the dynamic vibration absorber in the vertical direction of the machine body The parameters of the dynamic vibration absorber can be changed so as to coincide with the natural frequency of the entire body in the vertical direction of the body.

  According to a second aspect of the present invention, in the work vehicle according to the first aspect, any or all of the stay, the elastic body, and the mass body are slidably provided.

  According to a third aspect of the present invention, in the work vehicle according to the first aspect, the dynamic vibration absorber includes a transfer body, and the transfer body sets an installation position of either or both of the mass body and the stay. It is made to slide.

  According to a fourth aspect of the present invention, in the work vehicle according to the third aspect of the present invention, the transfer body is configured to be based on detection information of a detector that detects acceleration of the airframe attached to the airframe. It is connected to an analyzer for analyzing the frequency.

  According to the first aspect of the present invention, in a work vehicle provided with a seat for steering at the upper part of the fuselage, the seat pan below the seat and the stay supporting the seat on the seat pan are substantially parallel to the seat pan. A dynamic vibration absorber comprising an elastic body provided between the arm attached to the arm and a mass body attached to the stay, and the natural vibration frequency of the dynamic vibration absorber in the vertical direction of the machine body Since the parameters of the dynamic vibration absorber can be changed to match the natural frequency of the direction, the mass of the entire fuselage changes due to the attachment of the attachment, etc., or the tire drive when the vehicle drive part is a wheel type Even if the tire spring constant changes depending on the type, change the parameters such as replacing the mass body and elastic body constituting the dynamic vibration absorber and adjusting the installation position. Of the natural frequency, to match the natural frequency of the fuselage vertical whole body can be absorbed by the resonance vibration of the fuselage vertical propagated from fuselage sheet. Accordingly, it is possible to provide a work vehicle in which the vibration propagated from the machine body to the seat is reduced and the work environment is improved.

  According to the invention described in claim 2, since any or all of the stay, the elastic body, and the mass body are slidably provided, the mass of the entire body changes due to attachment of the attachment, Even if the spring constant of the tire changes depending on the type of tire when the vehicle drive unit is a wheel type, any or all of the mass body, elastic body, and stay installation position that make up the dynamic vibration absorber can be easily As a result of adjustment, by changing the parameters of the dynamic vibration absorber, the natural frequency in the vertical direction of the body of the dynamic vibration absorber is made to match the natural frequency of the whole body in the vertical direction of the body and propagates from the body to the seat. The vibration in the vertical direction of the machine body can be absorbed by resonance. Accordingly, it is possible to provide a work vehicle in which the vibration propagated from the machine body to the seat is reduced and the work environment is improved.

  According to the third aspect of the present invention, the dynamic vibration absorber includes the transfer body, and the transfer body slides the installation position of either or both of the mass body and the stay. As a result of the change, the mass body and stay can be automatically slid to the preset installation position by the transfer body. As a result, the parameters of the dynamic vibration absorber can be easily changed. Therefore, the vibration in the vertical direction of the airframe transmitted from the airframe to the seat can be absorbed by resonance. Accordingly, it is possible to provide a work vehicle in which the vibration propagated from the machine body to the seat is reduced and the work environment is improved.

  According to the invention described in claim 4, since the transfer body is connected to the analyzer for analyzing the natural frequency of the airframe based on the detection information of the detector attached to the airframe that detects the acceleration of the airframe. The result is that the mass body and stay can be automatically slid by the transfer body to the installation position corresponding to the natural frequency in the vertical direction of the entire body calculated from the detected acceleration of the traveling body. By easily changing the parameters of the dynamic vibration absorber, the natural frequency of the dynamic vibration absorber in the vertical direction of the fuselage is matched to the natural frequency of the entire aircraft in the vertical direction of the aircraft. Directional vibration can be absorbed by resonance. Accordingly, it is possible to provide a work vehicle in which the vibration propagated from the machine body to the seat is reduced and the work environment is improved.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a left side view of a wheel tractor as a work vehicle according to an embodiment of the present invention, and FIG. 2 is a plan view of the tractor.

  A tractor 1 which is a working vehicle of this example includes a front wheel 3 and a rear wheel 4 before and after a body frame 2, a bonnet 5 is formed above the front wheel 3, and an engine 6 and an engine 6 as a prime mover part are formed inside thereof. A clutch housing 7 is disposed at the rear, and a transmission case 8 is disposed at the rear of the clutch housing 7, and power from the engine 6 is transmitted to the front wheels 3 and the rear wheels 4. A cabin 9 is provided on the body frame 2 continuously to the rear part of the bonnet 5. The drive unit of the tractor 1 is not limited to the wheel type as described above, and may be a crawler type.

  Next, an operating pedal 10 such as a brake pedal or a clutch pedal, a steering handle 11, and a seat 12, which is a main part of the present invention to be described later, are provided in the cabin 9 as vehicle operating units. Further, the left and right fenders 13 provided on both sides of the seat 12 are provided with various operation levers 14 such as a main transmission lever, a sub transmission lever, and a PTO transmission lever protruding. And the windshield 15, the rear glass 16, the door 17, the roof 18, etc. may be attached to the outer periphery of the cabin 9, respectively. Also, below the cabin 9, an elevating step 19 for the driver to get on and off the cabin 9 is fixed to the body frame 2.

  The power from the engine 6 is transmitted to a PTO shaft (not shown) protruding from the rear end of the transmission case 8, and from this PTO shaft via a work equipment mounting device 20 such as a universal joint or a three-point link type (not shown). A working machine (not shown) attached to the rear end of the vehicle is driven.

  Next, a specific configuration of the vibration-proof sheet that reduces vibration propagated from the machine body to the sheet will be described. 3 is an external perspective view of a sheet having an internal vibration isolation structure, FIG. 4 is a schematic side view of the sheet showing the internal vibration isolation structure, and FIG. 5 is an enlarged schematic side view of the dynamic vibration absorber showing each parameter. 6 is a schematic side view of the vicinity of the dynamic vibration absorber showing the sliding of the mass body, FIG. 7 is a schematic side view of the vicinity of the dynamic vibration absorber showing the change of the installation position of the elastic body, and FIG. FIG. 9 is a schematic side view of the vicinity of the vibration absorber, FIG. 9 is a schematic side view of the vicinity of the dynamic vibration absorber provided with a transfer body in the mass body, and FIG. 10 is a schematic side view of the vicinity of the dynamic vibration absorber that automatically controls the sliding position of the mass body. .

  As shown in FIG. 3, the seat 12 used for maneuvering the aircraft is provided on the floor 21 at the bottom of the cabin 9, for example. As shown in FIG. 4, the seat 12 is provided with a pantograph 22 on the floor 21 that can adjust the vertical height position of the seat 12, and on the front and rear of the mounting table 23 fixed on the pantograph 22. A seat pan 26 is fixed through the provided stays 24 and 25. Then, the sheet 12 is mounted on the seat pan 26.

  Next, a dynamic vibration absorber 28 for absorbing vibration generated in the vertical direction of the entire machine body is attached between the stays 24 and 25 and in a space s between the seat pan 26 and the mounting table 23. . This dynamic vibration absorber 28 is attached to one end of the stay 25 below the seat pan 26, and has an arm 29 made of metal or the like provided substantially parallel to the seat pan 26. It is composed of a mass body 30 that is a weight of a steel ball or the like attached in the vicinity of the end, and an elastic body 31 such as a spring made of metal or the like attached between the seat pan 26 and the arm 29. The The space s can be covered with covers 32 provided on both sides of the stays 24 and 25. Further, the arm 29 may be attached to the stay 24.

  One end of the arm 29 attached to the middle portion of the stay 25 serves as a fulcrum a of the dynamic vibration absorber 28. The material and shape of the arm 29 and the mass body 30 are not limited.

Here, as shown in FIG. 5, the mass of the mass body 30 in the dynamic vibration absorber 28 is m (kg), the spring constant of the elastic body 31 is k (N / m), and the distance of the elastic body 31 from the fulcrum a is When r (m), the distance of the mass body 30 from the fulcrum a is L (m), and the natural frequency of the vibration of the entire aircraft in the vertical direction of the aircraft is f (Hz), this natural frequency f is It is represented by Formula A.
f = (1 / 2π) × (r / L) × (A)

  Therefore, parameters such as the mass m of the mass body 30 in the dynamic vibration absorber 28, the spring constant k of the elastic body 31, the distance r of the elastic body 31 from the fulcrum a, and the distance L of the mass body 30 from the fulcrum a are set. Then, by making the natural frequency f in the vertical direction of the dynamic vibration absorber 28 coincide with the natural frequency f in the vertical direction of the entire body, the vertical vibration of the entire body resonates with the vertical vibration of the dynamic vibration absorber 28. Thus, the vertical vibration of the entire machine body is absorbed by the dynamic vibration absorber 28, and the vertical vibration of the entire machine body transmitted to the seat 12 is reduced, so that the operator can obtain a comfortable work space with little vibration.

  However, when the mass of the machine changes due to attachment or replacement of various work machines to the rear of the machine, or when the tire spring constant changes due to tire replacement of the front wheels 3 and rear wheels 4, etc. Since the natural frequency f in the direction also changes and does not coincide with the natural frequency f in the vertical direction in the dynamic vibration absorber 28 in which each parameter is set in advance as described above, the vertical vibration and dynamic vibration absorber 28 of the entire body are not matched. Therefore, the vertical vibration of the entire body cannot be absorbed by the dynamic vibration absorber 28.

  In such a case, for example, the operator removes the cover 32 and replaces the mass body 30 with the mass body 30 with a different mass or the elastic body 31 with the elastic body 31 with a different spring constant or both. (At this time, the value of the distance r of the elastic body 31 from the fulcrum a and the value of the distance L of the mass body 30 from the fulcrum a are fixed.) Further, the natural frequency f in the vertical direction of the dynamic vibration absorber 28 can be easily matched.

  Further, in addition to the replacement of the mass body 30 and the elastic body 31, the distance r of the elastic body 31 from the fulcrum a and the distance L of the mass body 30 from the fulcrum a are changed so The natural frequency f in the vertical direction of the dynamic vibration absorber 28 can be matched with the frequency f.

  In this case, for example, as shown in FIG. 6, first, a mass body 30 penetrating the arm 29 is provided slidably with respect to the arm 29, and before and behind the mass body 30 on the arm 29. The stopper 33 is provided in contact with the mass body 30.

  With such a configuration, the conditions of the work machine, tires, and the like change as described above, and the natural frequency f in the vertical direction of the dynamic vibration absorber 28 matches the vertical natural frequency f in the changed entire body. For example, the operator removes the cover 32, loosens a screw (not shown) of the stopper 33, slides the mass body 30 along the arm 29 in the longitudinal direction of the machine body, and the distance L of the mass body 30 from the fulcrum a corresponds to After adjusting the position (at this time, the mass m of the mass body 30, the spring constant k of the elastic body 31 and the distance r of the elastic body 31 from the fulcrum a are fixed), the screw of the stopper 33, etc. Is fastened to fix the mass body 30. The arm 29 is formed by a screw and the stopper 33 is a lock nut so that the mass body 30 is slid along the arm 29 in the front-rear direction by turning the screw of the arm 29. Good.

  The installation position by sliding the mass body 30 on the arm 29 may be arbitrarily set according to the operator's feeling, but the entire body calculated in advance by the weight of the body by a work machine or the spring constant of the tire. It is also possible to set the distance L of the mass body 30 from the fulcrum a set in advance based on the natural frequency f in the vertical direction at.

  Next, the values of the distance L of the mass body 30 from the fulcrum a, the mass m of the mass body 30 and the spring constant k of the elastic body 31 are fixed, and the value of the distance r of the elastic body 31 from the fulcrum a Thus, the natural frequency f in the vertical direction of the dynamic vibration absorber 28 can be made to coincide with the natural frequency f in the vertical direction of the entire changed body as described above. In this case, as shown in FIG. 7, hooks 34 are appropriately provided at a plurality of locations at equal intervals in the longitudinal direction of the machine body between the lower end portion of the seat pan 26 and the arm 29.

  With such a configuration, the conditions of the work machine, tires, and the like change as described above, and the natural frequency f in the vertical direction of the dynamic vibration absorber 28 matches the vertical natural frequency f in the changed entire body. For example, the operator removes the cover 32 and hangs the elastic body 31 on the corresponding hook 34 in the longitudinal direction of the body to adjust the value of the distance r of the elastic body 31 from the fulcrum a. The natural frequency f in the vertical direction of the dynamic vibration absorber 28 can be set to the natural frequency f. The installation position of the elastic body 31 by being hooked on the hook 34 may be arbitrarily set according to the operator's feeling, as described above, but the weight of the machine body by a working machine or the tire spring depending on the type of tire. The hook 34 can be a distance r of the elastic body 31 from the fulcrum a set in advance based on the natural frequency f in the vertical direction of the entire body calculated in advance by a constant.

  Further, as described above, the distance L of the mass body 30 from the fulcrum a, the mass m of the mass body 30 and the spring constant k of the elastic body 31 are fixed, and the stay 25 is slid to move from the fulcrum a. Only the distance r of the elastic body 31 can be changed. In this case, as shown in FIG. 8, a plurality of position adjustment holes 35 are appropriately provided in the left and right side portions of the seat pan 26, and the upper portion of the stay 25 provided in the left and right side portions of the seat pan 26, Fastening holes 36 that can be fastened with fasteners 37 such as bolts are provided on both the left and right sides in alignment with the position adjustment holes 35. The lower end portion of the elastic body 31 is locked to a hook (not shown) of a sliding member 38 such as a cylinder (the shape and structure are not limited) provided to be slidable on the arm 29.

  With such a configuration, the conditions of the work machine, tires, and the like change as described above, and the natural frequency f in the vertical direction of the dynamic vibration absorber 28 matches the vertical natural frequency f in the changed entire body. For example, the operator removes the cover 32, loosens the fastener 37 that fastens the position adjustment hole 35 and the fastening hole 36, slides the stay 25 in the longitudinal direction of the machine body, and moves the fastening hole 36 of the stay 25 to the seat pan 26. It matches with the corresponding position adjustment hole 35. At this time, the lower end portion of the elastic body 31 can be slid to a position vertically below the upper end portion of the elastic body 31 fixed by the sliding member 38 corresponding to the sliding of the arm 29 accompanying the stay 25. it can. Then, the value of the distance r of the elastic body 31 from the fulcrum a is adjusted by fastening both with the fastener 37, and the vertical direction in the dynamic vibration absorber 28 matched with the natural frequency f in the vertical direction in the entire machine body. Of the natural frequency f.

  As described above, the sliding position of the stay 25 may be arbitrarily set according to the operator's feeling. However, the airframe calculated in advance based on the weight of the airframe due to the working machine or the spring constant of the tire depending on the type of tire. Based on the natural frequency f in the vertical direction in the whole, the position can be a position where the distance r of the elastic body 31 from the fulcrum a set in advance.

  With the above configuration, even if the mass of the entire fuselage changes due to attachments, etc., or even if the spring constant of the tire changes due to the type of tire when the vehicle drive unit is a wheel type, dynamic vibration absorption By changing each parameter such as replacement of the mass body 30 and elastic body 31 constituting the device 28 and adjustment of the installation position, the natural vibration frequency of the dynamic vibration absorber 28 in the vertical direction of the aircraft is changed. The vibrations in the vertical direction of the airframe transmitted from the airframe to the seat 12 can be absorbed by resonance so as to match the natural frequency. In addition, the replacement of the mass body 30 and the elastic body 31 and the sliding of the mass body 30, the elastic body 31, or the stay 25, which are the work for changing each parameter described above, are performed individually, and all the parameters are changed simultaneously. It may be implemented or changed in combination.

  Next, the parameters as described above are automatically changed so that the natural frequency in the vertical direction of the body of the dynamic vibration absorber 28 matches the natural frequency in the vertical direction of the body of the entire body, and the seat 12 The vibration in the vertical direction of the machine body that is propagated to the vehicle can be absorbed by resonance. FIG. 9 is a schematic side view of the vicinity of the dynamic vibration absorber showing the sliding of the mass body including the actuator, and FIG. 10 is a schematic side view of the vicinity of the dynamic vibration absorber that automatically controls the sliding of the mass body including the actuator.

  In this case, for example, as shown in FIG. 9, an actuator that is slidable along the arm 29, which is similar to the mass body 30 and includes a pulse motor, a pinion slide mechanism, and the like that penetrates the arm 29. A transfer body 39 is attached to the mass body 30. A switch 40 (not shown in detail) that slides the transfer body 39 is provided in the vicinity of the sheet 12 (the installation position is not limited) via a controller 41 (not shown in detail). At this time, the mass m of the mass body 30 in the dynamic vibration absorber 28 may be obtained by adding the mass of the transfer body 39 to the mass of the mass body 30.

  By adopting such a configuration, the conditions of the work machine, tires, and the like are changed as described above, and the natural frequency f in the vertical direction of the dynamic vibration absorber 28 is changed to the natural frequency f in the vertical direction in the changed whole body. When matching, the operator operates the switch 40 in the vicinity of the sheet 12, for example, and the mass body 30 is slid to the corresponding position together with the transfer body 39 according to an instruction from the controller 41. As a result, the natural vibration frequency of the dynamic vibration absorber 28 in the vertical direction of the fuselage is made to match the natural frequency of the entire fuselage in the vertical direction of the fuselage, and vibration in the vertical direction of the fuselage transmitted from the fuselage to the seat 12 is absorbed by resonance. Can do.

  The sliding positions of the mass body 30 and the transfer body 39 may be arbitrarily set by the switch 40 according to the operator's feeling, as described above. However, the weight of the machine body by the work machine or the tire type depending on the tire type may be set. The switch 40 can be set so that the distance L of the mass body 30 from the fulcrum a set in advance by the controller 41 is based on the natural frequency in the vertical direction of the entire body calculated in advance by the spring constant. .

  Further, the installation of the transfer body 39 is not limited to the mass body 30, for example, it is attached to the previously operated stay 25 (or the stay 24) and the stay 25 is automatically slid by the operation of the switch 40, Alternatively, the stay 25 and the mass body 30 may be attached to both the stay 25 and the mass body 30, and the stay 25 and the mass body 30 may be slid simultaneously.

  Furthermore, parameter changes can be automatically controlled. In this case, as shown in FIG. 10, for example, a detector 42 such as an acceleration sensor for detecting the acceleration of the airframe is mounted on the mounting table 23 (the installation position is not limited). The detector 42 may be a contact type, a non-contact type, or the like, and the type of the electric signal conversion method is not limited to a piezoelectric type, a charge type, or a voltage type.

  The detector 42 is operated based on the detection information of the detector 42 and calculates the natural frequency of the vibration in the vertical direction of the aircraft that occurs in the entire aircraft. 43 is connected, and the analyzer 43 is connected to the transfer body 39 via the controller 41. Moreover, the transfer body 39 is attached to the mass body 30, for example as mentioned above.

  By adopting such a configuration, the conditions of the work machine, tires, and the like are changed as described above, and the natural frequency f in the vertical direction of the dynamic vibration absorber 28 is changed to the natural frequency f in the vertical direction in the changed whole body. When matching, the acceleration of the airframe detected by the detector 42 by traveling for a certain period or time by running the airframe is the vibration of the vertical motion of the airframe generated by the analyzer 43 in the entire airframe (vertical direction). A natural frequency is calculated. Then, based on the value of the distance L of the mass body 30 from the fulcrum a calculated from the natural frequency by the analyzer 43, the controller 41 slides the transfer body 39 to slide the mass body 30 to the position, The natural vibration frequency of the dynamic vibration absorber 28 in the vertical direction of the machine body is made to coincide with the natural frequency of the entire machine body in the vertical direction of the machine body, and vibrations in the vertical direction of the machine body transmitted from the machine body to the seat 12 can be absorbed by resonance.

  At this time, the installation of the transfer body 39 is not limited to the mass body 30. For example, the transfer body 39 is attached to the previously operated stay 25 (or the stay 24) and the stay 25 is used as information from the detector 42 and the analyzer 43. On the basis of this, the controller 41 may be automatically slid, or may be attached to both the stay 25 and the mass body 30, and the stay 25 and the mass body 30 may be slid simultaneously.

  With the above configuration, even if the mass of the entire fuselage changes due to attachments, etc., or even if the spring constant of the tire changes due to the type of tire when the vehicle drive unit is a wheel type, dynamic vibration absorption Since the installation positions of the mass body 30 and the stay 25 constituting the device 28 are easily adjusted by automatic sliding, the natural vibration frequency of the dynamic vibration absorber 28 in the vertical direction of the airframe is determined as the natural vibration in the vertical direction of the entire airframe. The number of vibrations in the vertical direction of the aircraft transmitted from the aircraft to the seat 12 can be absorbed by resonance. The dynamic vibration absorber 28 is not limited to be installed below the seat 12, and when the cabin 9 is provided, the dynamic vibration absorber 28 is installed at the lower end portion of the cabin 9, so that the vertical direction of the aircraft propagated from the aircraft to the cabin 9. The vibration may be reduced.

  As described in detail above, the tractor 1 of this example includes the seat 12 for steering at the upper part of the fuselage, the seat pan 26 below the seat 12, and the stay 25 that supports the seat 12 on the seat pan 26. In addition, a dynamic vibration absorber 28 including an elastic body 31 provided between the seat pan 26 and an arm 29 attached substantially parallel to the seat pan 26 and a mass body 30 attached to the stay 25 is provided. The parameter of the dynamic vibration absorber 28 can be changed so that the natural frequency f in the direction matches the natural frequency f in the vertical direction of the entire aircraft. In addition, any or all of the stay 25, the elastic body 31, and the mass body 30 are slidably provided, and the dynamic vibration absorber 28 includes a transfer body 39. 30 and / or the stay 25 is slid, and the transfer body 39 is attached to the airframe, and the natural vibration of the airframe is detected based on the detection information of the detector 42 that detects the acceleration of the airframe. Connect to the analyzer 43 which analyzes the number f.

  Moreover, in the above-mentioned example, the wheel type tractor (agricultural working machine) has been described as an example of the working vehicle, but the present invention is not limited to this. As a construction work machine, it can be applied to any work vehicle equipped with a seat and cabin for steering, such as a backhoe and a bulltoza.

It is a left view which shows the wheel type tractor as an example of this invention. It is a top view of a wheel type tractor. It is an external appearance perspective view of a sheet | seat provided with an anti-vibration structure inside. It is the side surface schematic diagram of the sheet | seat which showed the internal anti-vibration structure. It is the side surface schematic diagram which expanded the dynamic vibration damper which shows each parameter. It is a side surface schematic diagram near the dynamic vibration absorber which shows sliding of a mass body. It is a side surface schematic diagram of the dynamic vibration absorber vicinity which shows the installation position change of an elastic body. It is a side surface schematic diagram near the dynamic vibration absorber which shows the sliding of a stay. It is a side surface schematic diagram of dynamic vibration absorber vicinity provided with a transfer body in a mass body. It is a side surface schematic diagram of the dynamic vibration absorber vicinity which controls automatically the sliding position of a mass body.

Explanation of symbols

12 Seat 21 Floor 22 Pantograph 23 Mounting table 24, 25 Stay 26 Seat pan 28 Dynamic vibration absorber 29 Arm 30 Mass body 31 Elastic body 32 Cover 33 Stopper 34 Hook 35 Position adjustment hole 36 Fastening hole 37 Fastening tool 38 Sliding member 39 Transfer Body 40 switch 41 controller 42 detector 43 analyzer A formula a fulcrum s space f natural frequency r distance of the elastic body from the fulcrum L distance of the mass from the fulcrum k spring constant m mass of the mass

Claims (4)

In a work vehicle equipped with a seat for steering at the top of the fuselage,
An elastic body provided between a seat pan below the seat and an arm attached to a stay supporting the sheet on the seat pan substantially parallel to the seat pan;
A mass attached to the stay;
A dynamic vibration absorber made of
Natural frequency of the machine body vertical direction of the dynamic vibration reducer is, the machine body whole (we have modified all below) to match the natural frequency of the machine body vertically, changing the parameters of the dynamic vibration reducer A work vehicle characterized by being made possible.   The work vehicle according to claim 1, wherein any one or all of the stay, the elastic body, and the mass body are slidably provided.   2. The work vehicle according to claim 1, wherein the dynamic vibration absorber includes a transfer body and causes the transfer body to slide an installation position of either or both of the mass body and the stay.   The said transfer body is connected to the analyzer which analyzes the said natural frequency of the said airframe based on the detection information of the detector which detects the acceleration of this airframe attached to the said airframe. The work vehicle as described in.

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