Work vehicle

Abstract

To provide a work vehicle capable of avoiding a main frame from contacting a crawler belt while enabling a change in the back-and-forth inclination attitude relating to the track frame of the main frame.SOLUTION: A work vehicle includes: a plurality of guide wheels 7; a pair of crawler belts 8; a track frame 9; a pair of main frames 10 that support a machine body; and a pair of attitude change operating means SH capable of performing an operation so as to change an up-and-down position of the main frame 10 and a back-and-forth inclination attitude thereof relative to the track frame 9. The attitude change operating means SH includes: a front-side first swing linkage 24 that is pivotably coupled across the track frame 9 and the main frame 10; a rear-side second swing linkage 25; and a drive unit capable of performing swinging operation individually on the front and back swing linkages 24 and 25. Furthermore, a restricting member 37 is provided which restricts the up-and-down position of the main frame 10 relative to the track frame 9 to a predetermined up-and-down position when the main frame 10 changes the attitude to a front-up inclination attitude.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a work vehicle, such as a combine harvester or a tractor, that is equipped with a crawler travel device. [Background technology]

[0002] The crawler travelling device provided on a work vehicle is pivotally connected via a pair of front and rear swing links to a track frame that supports multiple contact rollers and tensioning wheels, and a main frame that supports the vehicle body, and is equipped with multiple drive mechanisms (hydraulic cylinders) that can swing the front and rear swing links separately. By using such a crawler travelling device, it is possible to change the height above the ground of the work vehicle and its tilt attitude for the front and rear. Conventionally, there has been a system configured as follows.

[0003] A large-diameter tension ring is used at the rear of the machine body, and the swing link at the rear is connected to the track frame via another link (called an auxiliary link or a cancel link) to absorb assembly errors, etc. When the main frame reaches its lowest position parallel to the track frame, a support shaft provided at the swing fulcrum of the swing link comes into contact with the main frame to restrict its position (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-96774 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described conventional configuration, the rear swing link is pivotally connected to the track frame via another link, so when the main frame assumes a forward-downward position relative to the track frame, the front-to-rear position of the main frame relative to the track frame may be slightly misaligned in the front-to-rear direction compared to when the track frame and the main frame are parallel.

[0006] As a result, when the main frame assumes a forward-downward position relative to the track frame, the track frame and the main frame may become close to each other near the rear swing link, which may cause the rear portion of the main frame to come into contact with the crawler belt.

[0007] In order to improve the crawler's ability to maneuver through wet fields, it is possible to reduce the size of the tensioning wheels and set them higher than the guide wheels, giving the rear contact surface of the crawler belt an inclined, upward-sloping position. However, when such a configuration is adopted, there is a particularly high risk that the rear part of the main frame will come into contact with the crawler belt.

[0008] Therefore, there has been a demand for a system that allows the forward / backward tilting posture of the main frame relative to the track frame to be changed while also preventing the main frame from coming into contact with the crawler belt. [Means for solving the problem]

[0009] A characteristic configuration of a work vehicle according to the present invention comprises a plurality of guide wheels, a crawler belt wound around the plurality of guide wheels, a track frame supporting the plurality of guide wheels, a main frame supporting a machine body, and attitude change operation means capable of changing the up-down position and fore-aft tilt attitude of the main frame relative to the track frame, the attitude change operation means having a front first swing link pivotally connected between the track frame and the main frame, a rear second swing link pivotally connected between the track frame and the main frame, and a drive unit capable of swinging the first swing link and the second swing link separately, and comprising a restricting member that restricts the approach distance of the main frame to a predetermined distance from the rear end of the track frame when the front part of the main frame has risen to a maximum raised position and the rear part of the main frame has lowered to a maximum lowered position, switching to a maximum front upward tilt attitude. The regulating member includes a first regulating portion that acts when the front portion of the main frame and the rear portion of the main frame are switched from a fully lowered position, in which they are lowest relative to the track frame, to the maximum front upward tilt position, and a second regulating portion that acts when the front portion of the main frame and the rear portion of the main frame are switched from a fully raised position, in which they are highest relative to the track frame, to the maximum front upward tilt position. The point is that

[0010] According to the present invention, when the main frame is switched to a front-upward tilted posture relative to the track frame, the restricting member restricts the approach distance of the main frame to a predetermined distance from the rear end of the track frame. As a result, even in a configuration in which the rear second swing link is connected to the track frame via a separate link to absorb assembly errors, etc., when the main frame is in the front-upward tilted posture, it is possible to maintain the vertical position of the rear part of the main frame at a vertical position that does not contact the crawler belt.

[0011] Therefore, it is possible to change the forward / backward tilting attitude of the main frame relative to the track frame while avoiding contact of the main frame with the crawler belt. Furthermore, when the main frame switches from a fully lowered position to a front-upward tilted position relative to the track frame, the front portion swings upward with the connecting point of the main frame on the second swing link side as a fulcrum. If the second swing link is connected via another link, the connecting point of the main frame on the second swing link side may move back and forth. On the other hand, when the main frame switches from a fully raised position to a front-upward tilted position relative to the track frame, the rear portion swings downward with the connecting point of the main frame on the first swing link side as a fulcrum. As a result, when switching from the fully lowered position to the front-upward tilt position, the manner in which the main frame changes position relative to the track frame differs from when switching from the fully raised position to the front-upward tilt position, and the contact position with the regulating member when the front-upward tilt position is reached changes. Therefore, by providing a first regulating member that acts when switching from the fully lowered position to the front-upward tilt position and a second regulating member that acts when switching from the fully raised position to the front-upward tilt position, it is possible to always perform appropriate position regulating operations.

[0012] In the present invention, it is preferable that the second swing link comes into contact with the restricting member to restrict the approach distance to the predetermined distance.

[0013] Because the main frame is located higher than the crawler belt, there is a large gap between the main frame and the track frame. As a result, if the restricting member were to contact the main frame, the restricting member would be large and complex. However, with this configuration, the restricting member contacts the second swing link, which is located close to the track frame, so it is possible to make the restricting member small and compact.

[0014] In the present invention, it is preferable that a swing fulcrum portion of the second swing link on the main frame side abuts against the restricting member.

[0015] With this configuration, the swing fulcrum portion of the second swing link on the main frame side moves up and down integrally with the main frame, and the load is supported by the main frame, so that the vertical position of the main frame can be accurately regulated.

[0016]

[0017]

[0018]

[0019] In the present invention, it is preferable that a position holding member be provided for holding the vertical position of the main frame relative to the track frame when the main frame is in the fully lowered position.

[0020] With this configuration, when the main frame is in the fully lowered position, it can be placed in as low and stable a position as possible, while preventing the main frame from coming closer to the track frame than necessary due to assembly errors or changes over time.

[0021] In the present invention, it is preferable that a downwardly open grooved portion is formed in the second swing link, and that when the main frame is in the fully lowered position, the regulating member enters and is stored in the grooved portion of the second swing link.

[0022] With this configuration, when the main frame is switched to the fully lowered position, the restricting member enters and is housed in the groove of the second swing link, thereby preventing the main frame from being unnecessarily high in the vertical direction when in the fully lowered position.

[0023] In the present invention, it is preferable that the plurality of guide wheels include a plurality of ground-contact guide wheels that guide the crawler belt against the ground, and a tensioning guide wheel located at the rear end, and that the tensioning guide wheel is located at a higher position than the plurality of ground-contact guide wheels, and that the underside of the rear end of the crawler belt is formed in a rearward-rising inclined position.

[0024] According to this configuration, the underside of the rear end of the crawler belt is formed in an inclined position with the rear rising upward, thereby improving the traveling performance when traveling backward through wet rice fields. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is an overall side view of a combine harvester. [Figure 2] FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 2 is a side view of the crawler traveling device in a fully lowered position. [Figure 5] FIG. 2 is a side view of the crawler travelling device in the maximum front-raised position. [Figure 6] FIG. 2 is a side view of the crawler traveling device in a fully raised position. [Figure 7] FIG. 2 is a side view of the crawler travelling device in the maximum front-raised position. [Figure 8] 10 is a side view of the restricting member mounting portion in a state where the first restricting portion is in operation. FIG. [Figure 9] 10 is a side view of the restricting member mounting portion in a state where the second restricting portion is in operation. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the direction indicated by the symbol (F) is the front side of the aircraft body, the direction indicated by the symbol (B) is the rear side of the aircraft body, the direction indicated by the symbol (U) is the upper side, and the direction indicated by the symbol (D) is the lower side.

[0027] [Overall structure] FIG. 1 shows a head-feeding combine as a work vehicle according to the present invention.

[0028] The combine harvester is equipped with a reaping unit 1 that raises and processes planted culms of rice, wheat, etc. and transports the reaped culms to the rear of the machine body, a rider-type driving unit 2, a threshing device 3 that threshers the reaped culms from the reaping unit 1, a grain tank 4 that stores the grains threshed by the threshing device 3, and a traveling body A equipped with an engine (not shown) located below the driving unit 5. It is also equipped with a pair of left and right crawler traveling devices B that support the traveling body A and drive it to travel.

[0029] [Crawler traveling device] The crawler traveling device B will be described below. 2 to 5, the crawler traveling device B includes a plurality of guide wheels 7, a crawler belt 8 wound around the plurality of guide wheels 7, a track frame 9 that supports the plurality of guide wheels 7, and a main frame 10 that supports the traveling body A. The front of the crawler traveling device B is provided with a drive wheel 11 to which power is transmitted from an engine E mounted on the traveling body A.

[0030] The plurality of guide wheels 7 are provided with a plurality (seven) of ground contact guide wheels 12 (hereinafter referred to as ground contact wheels) that guide the crawler belt 8 on the ground, and a tensioning guide wheel 13 (hereinafter referred to as tension wheel) located at the rearmost part. An upper guide wheel 14 is provided at a midpoint in the fore-and-aft direction of the main frame 10. The crawler belt 8 is wound around the drive wheels 11, ground contact wheels 12, tension wheels 13, and upper guide wheel 14.

[0031] The tensioning wheels 13 are provided at a position higher than the plurality of ground contact rollers 12. As a result, the lower surface of the rear end of the crawler belt 8 is formed in an inclined position with the rear rising upward.

[0032] 2 and 3, the truck frame 9 comprises an upper frame portion 9A shaped like a square pipe, a lower frame portion 19B shaped like a square pipe fixed to the underside of the upper frame portion 9A, a support frame portion 9C shaped like a square pipe connected to the rear of the upper frame portion 9A, and an extension frame portion 9D shaped like a square pipe fitted internally to the support frame portion 9C and mounted so as to be slidable in the fore-and-aft direction of the vehicle. A tension ring 13 is supported at the rear end of the extension frame portion 9D. The extension frame portion 9D is provided so that its position can be changed and adjusted in the fore-and-aft direction of the vehicle relative to the support frame portion 9C by a position adjustment mechanism 19 that utilizes a screw mechanism.

[0033] The drive wheels 11 are provided so that power is transmitted from a transmission case 20 (see Figure 1) fixed to the main frame 10 and engage with the crawler belt 8 to transmit the driving force. The upper guide wheels 14 are supported by the main frame 10 so that they rotate freely by contacting the inner circumferential surface of the upper side of the crawler belt 8. As shown in Figure 3, the ground contact rollers 12 are configured as outer rollers in which rotating bodies 22 are fixed to both ends of a rotating shaft 21 and each rotating body 22 contacts the inner circumferential surface of the crawler belt 8 on both the left and right sides of the left and right core metal protrusions 23 of the crawler belt 8.

[0034] [Attitude change operation means] The vehicle is provided with a position change operation means SH that can change the vertical position and longitudinal tilt position of the main frame 10 relative to the track frame 9. The position change operation means SH includes a front first swing link 24 (hereinafter referred to as the front link) pivotally connected between the track frame 9 and the main frame 10, a rear second swing link 25 (hereinafter referred to as the rear link) pivotally connected between the track frame 9 and the main frame 10, and a drive unit that can swing the front and rear links 24, 25 separately. As shown in Figures 2 and 4 to 7, the drive unit includes a front hydraulic cylinder 26 (hereinafter referred to as the front cylinder) that drives and swings the front link 24, and a rear hydraulic cylinder 27 (hereinafter referred to as the rear cylinder) that drives and swings the rear link 25.

[0035] 4 to 7, the front link 24 is configured in a bell crank shape, and its bending point is pivotally supported on the main frame 10 so as to be swingable about a horizontal axis. A first extension arm 29 extending upward from the pivotal support point is connected to the front end of the front cylinder 26, and a second extension arm 30 extending rearward is pivotally connected to a front support shaft 31 fixed to the upper part of the truck frame 9 so as to be swingable. The rear end of the front cylinder 26 is pivotally connected to the main frame 10.

[0036] The rear link 25 has a first link member 32 configured in a bell crank shape and a second link member 33 whose one end is pivotally connected to the track frame 9 so as to be swingable. The first link member 32 is pivotally supported on the main frame 10 near its bending point so as to be swingable about a horizontal axis. A first extension arm 34 extending upward from the pivotal support point is connected to the rear end of the rear cylinder 27, and a second extension arm 35 extending rearward is pivotally connected to the other end of the second link member 33. The second link member is in a vertical position, generally along the up-down direction.

[0037] As shown in FIG. 3, a fulcrum shaft is supported on the lower frame portion 9B of the track frame 9, and one end of the second link member 33 is pivotally connected to the fulcrum shaft so as to be swingable.

[0038] As shown in FIG. 4, by keeping the front cylinder 26 in the fully extended state and the rear cylinder 27 in the fully contracted state, the main frame 10 is lowered to the maximum relative to the track frame 9, the machine frame 6 is at its lowest height above the ground, and the main frame 10 is in a fully lowered position, approximately parallel to the traveling surface.

[0039] 5, by keeping the front cylinders 26 in the fully retracted state and the rear cylinders 27 in the fully retracted state, the main frame 10 assumes a maximum front-upward tilted posture in which the ground height increases toward the front. Also, although not shown, by keeping the front cylinders 26 in the fully extended state and the rear cylinders 27 in the fully extended state, the main frame 10 can be switched to a maximum front-downward tilted posture in which the ground height decreases toward the front.

[0040] As shown in FIG. 6, by keeping the front cylinder 26 in the fully contracted state and the rear cylinder 27 in the fully extended state, the main frame 10 rises to the maximum relative to the track frame 9, the main frame 10 reaches its highest height above the ground, and the main frame 10 assumes a fully raised position, approximately parallel to the traveling surface.

[0041] Therefore, by driving the front cylinder 26 and rear cylinder 27 provided corresponding to the left and right crawler traveling devices B and changing the posture of the left and right crawler traveling devices B separately, it is possible to perform left and right rolling adjustments, pitching adjustments, etc., and the height position and posture of the machine body traveling can be selected as desired depending on the work purpose.

[0042] The second link member 33 constituting the rear link 25 can absorb slight errors in dimensional accuracy, such as manufacturing errors of the cylinders 26, 27 and the front and rear links 24, 25 themselves, assembly errors, or the occurrence of play over long-term use, and is therefore effective in ensuring smooth operation of the posture-changing operating means.

[0043] The crawler traveling device B is provided with a regulating member 37 that regulates the vertical position of the main frame 10 relative to the track frame 9 to a predetermined vertical position when the main frame 10 is switched to the maximum front upward tilt posture.

[0044] 3, the restricting member 37 is fixed integrally to the upper surface of the upper frame portion 9A of the truck frame 9. The restricting member 37 is made of a plate-like block that is narrow in the left-right direction and wide in the up-down and front-rear directions. The restricting member 37 is fixed to the upper surface of a base portion 38 that is fixed integrally to the upper surface of the upper frame portion 9A.

[0045] The regulating member 37 includes a first regulating portion 39 which acts when the main frame 10 switches from a fully lowered position in which it is parallel to the track frame 9 and is at its lowest position to a maximum front upward tilt position, and a second regulating portion 40 which acts when the main frame 10 switches from a fully raised position in which it is parallel to the track frame 9 and is at its highest position to a maximum front upward tilt position.

[0046] The first restricting portion 39 is located at the front of the upper surface of the restricting member 37 and is formed in a shape that slopes downward toward the front. When the front cylinder 26 is extended and retracted until it reaches its most contracted state from the fully lowered position shown in Fig. 4 to switch to the front-lowered inclined position, as shown in Figs. 5 and 8, the swing fulcrum portion 41 of the first link member 32 of the rear link 25 on the main frame 10 side comes into contact with the first restricting portion 39, thereby restricting the vertical position of the main frame 10. Line L1 shown in Fig. 5 indicates an imaginary line that follows the lower edge of the main frame 10 in the fully lowered position.

[0047] Additionally, the second regulating portion 40 is formed in a horizontal position at the rear of the upper surface of the regulating member 37. When the rear cylinder 27 is extended from the fully raised position shown in Fig. 6 to its maximum extended state and switched to the maximum front-down tilt position, as shown in Figs. 7 and 9, the swing fulcrum portion 41 of the first link member 32 of the rear link 25 on the main frame 10 side abuts against the second regulating portion 40, regulating the vertical position of the main frame 10. Line L2 shown in Fig. 7 indicates an imaginary line that follows the lower edge of the main frame 10 in the fully raised position.

[0048] In this way, the regulating member 37 can be contacted from above by the swing fulcrum portion 41 of the rear link 25 on the main frame 10 side, thereby regulating the approach distance of the main frame 10 to the rear end of the track frame 9 to a predetermined distance.

[0049] When the main frame 10 is in a position approximately parallel to the track frame, the swing fulcrum part 41 does not come into contact with the regulating member 37, and the vertical position is not regulated. However, a position maintaining member 42 is provided to maintain the vertical position of the main frame 10 relative to the track frame 9 when the main frame 10 is in the fully lowered position. The position maintaining member 42 is provided in a position on the rear link 25 where the swing fulcrum part 41 comes into contact from above when the main frame 10 is in the fully lowered position (see FIG. 4).

[0050] As shown in Figure 3, a downwardly open groove is formed in the rear link 25 in an area other than the swing fulcrum portion 41. When the main frame 10 descends in a position parallel to the track frame 9, the regulating member 37 enters and is housed in the groove 43 of the rear link 25. This prevents the main frame 10 from coming into contact with the regulating member 37 in the fully lowered position, thereby preventing the up-down position from being restricted.

[0051] [Another embodiment] (1) In the above embodiment, the regulating member 37 is configured to contact the swing fulcrum portion 41 of the rear link 25 (second swing link) on the main frame 10 side to regulate the vertical position. However, instead of this configuration, it may contact a portion of the rear link 25 (swing link) other than the swing fulcrum portion 41. may be.

[0052] (2) In the above embodiment, the rear link 25 (second swing link) is configured to have the grooved portion 43 that is open downward. However, such a grooved portion 43 may not be formed.

[0053]

[0054] ( 3 In the above embodiment, the tensioning guide wheels 13 are positioned higher than the plurality of ground contact guide wheels 12, and the underside of the rear end of the crawler belt 8 is formed in a rearward-rising inclined position. However, instead of this configuration, the tensioning wheels may be formed with a large diameter, and the rear end of the crawler belt 8 may be formed in an arc shape. It's okay to have it.

[0055] ( 4 In the above embodiment, a head-feeding combine was used as an example of a work vehicle, but the invention is not limited to head-feeding combines and may be a normal combine, and the invention is not limited to combines and may be a tractor or other work vehicle. [Industrial Applicability]

[0056] The present invention can be applied to work vehicles equipped with crawler travelling devices, such as combine harvesters and tractors. [Explanation of symbols]

[0057] 7 Guide Wheel 8 Crawler Belt 9 Track Frame 10 Mainframe 12 Ground guide wheel 13 Tension guide wheel 24 First swing link 25 Second swing link 26, 27 Hydraulic cylinder (drive mechanism) 37 Regulatory components 39 First Regulatory Department 40 Second Regulatory Department 41 Swing fulcrum 42 Position-retaining member 43 Groove

Claims

1. A plurality of guide wheels; a crawler belt wound around the plurality of guide wheels; a track frame supporting a plurality of the guide wheels; A main frame that supports the aircraft; and a position change operation means for changing the vertical position and the longitudinal tilt attitude of the main frame relative to the track frame, the attitude change operation means includes a front first swing link pivotally connected between the track frame and the main frame, a rear second swing link pivotally connected between the track frame and the main frame, and a drive unit capable of swinging the first swing link and the second swing link separately, a restricting member is provided that restricts the approach distance of the main frame to a rear end of the track frame to a predetermined distance when the front portion of the main frame is raised to a maximum raised position and the rear portion of the main frame is lowered to a maximum lowered position, thereby switching to a maximum front upward tilt posture; The regulating member is a first restriction portion that acts when the front portion of the main frame and the rear portion of the main frame are switched from a fully lowered position, in which they are lowered most relative to the track frame, to the maximum front upward tilt position; a second regulating portion that acts when the front portion of the main frame and the rear portion of the main frame are switched from the fully raised position, in which they are raised most relative to the track frame, to the maximum front upward tilt position.

2. The work vehicle according to claim 1, wherein the second swing link comes into contact with the restricting member to restrict the approach distance to the predetermined distance.

3. The work vehicle according to claim 2, wherein the restricting member is abutted by a swing fulcrum portion of the second swing link on the main frame side.

4. 2. The work vehicle according to claim 1, further comprising a position holding member that holds the vertical position of said main frame relative to said truck frame when said main frame is in said fully lowered position.

5. A downwardly open groove portion is formed in the second swing link, 5. A work vehicle according to claim 4, wherein the restricting member is received in and accommodated in the groove portion of the second swing link when the main frame is in the fully lowered position.

6. A work vehicle as described in any one of claims 1 to 5, wherein the plurality of guide wheels are provided with a plurality of ground-contact guide wheels that guide the crawler belt onto the ground and a tensioning guide wheel located at the rearmost position, the tensioning guide wheel is located at a higher position than the plurality of ground-contact guide wheels, and the underside of the rear end of the crawler belt is formed in a rearward-rising inclined position.

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