Work vehicle

Abstract

To provide a work vehicle that allows a positioning frame to be adjusted according to machine body vibration, a radio wave state, etc., and is high in safety at the time of the adjustment.SOLUTION: A positioning frame 20 is configured so as to be expanded and contracted in a vertical direction, and can be switched to a first posture in which at least a positioning device 30 is positioned at a first height according to an expansion and contraction operation, and a second posture in which the positioning device 30 is positioned at a second height lower than the first height. Further, the positioning frame 20 includes fall prevention means (detent mechanism 60) for stopping the fall of the positioning device 30 at a middle height between the first height and the second height when a hand is released from the positioning frame at the time of expansion and contraction operation.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a work vehicle such as a riding rice transplanter.

Background Art

[0002] There is known a work vehicle that acquires position information of a traveling body by a positioning device and displays the acquired position information or automatically travels the traveling body based on the acquired position information. For example, the work vehicle shown in Patent Document 1 includes a positioning frame in a front view inverted U shape erected at the front of the body, and acquires position information of the traveling body with a positioning device provided at the upper part of the positioning frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the positioning frame of Patent Document 1 is difficult to adjust according to factors such as body vibration and radio wave conditions, and there is room for improvement.

Means for Solving the Problems

[0005] The present invention was created for the purpose of solving these problems in view of the above circumstances. The invention according to claim 1 is a work vehicle comprising a traveling body, a positioning device for acquiring position information of the traveling body, and a front-view inverted U-shaped positioning frame erected on the traveling body and supporting the positioning device. The positioning frame is configured to be telescopically operable in the vertical direction, and in response to the telescopic operation, it can be switched to at least a first posture in which the positioning device is positioned at a first height and a second posture in which the positioning device is positioned at a second height lower than the first height. Further, the positioning frame is provided with a fall prevention means for stopping the fall of the positioning device at an intermediate height between the first height and the second height when the hand is released from the positioning frame during the telescopic operation. Moreover, the invention according to claim 2 is the work vehicle according to claim 1, wherein the fall prevention means is configured using a detent mechanism capable of locking the telescopic movement of the positioning frame at the intermediate height, and the detent mechanism is provided with a locking release means for releasing the locking in response to a predetermined operation. Moreover, the invention according to claim 3 is the work vehicle according to claim 2, wherein the detent mechanism is configured to be able to lock the telescopic movement of the positioning frame at the intermediate height, the first height, and the second height. Moreover, the invention according to claim 4 is the work vehicle according to claim 2, wherein the positioning frame has left and right vertical frame portions extending upward from the traveling body and a horizontal frame portion connecting the upper ends of the left and right vertical frame portions, the positioning device is attached to the horizontal frame portion, the height is switched in response to the telescopic operation of the vertical frame portion, and the fall prevention means is provided only on one of the left and right vertical frame portions.

Advantages of the Invention

[0006] According to the invention of claim 1, the positioning frame is configured to be telescopically operable in the vertical direction. In response to the telescopic operation, at least the first posture for positioning the positioning device at the first height and the second posture for positioning the positioning device at the second height lower than the first height can be switched. Therefore, it is possible to adjust according to the situation, such as reducing the influence of the body vibration with the positioning device at the second height or increasing the reception sensitivity with the positioning device at the first height. Further, the positioning frame is provided with a fall prevention means for stopping the fall of the positioning device at an intermediate height between the first height and the second height when the hand is released from the positioning frame during the telescopic operation. This not only improves the safety during the telescopic operation but also prevents the positioning device from being damaged by the impact associated with the fall. Also, according to the invention of claim 2, the fall prevention means is configured using a detent mechanism that can lock the telescopic movement of the positioning frame at the intermediate height. The detent mechanism is provided with a locking release means for releasing the lock in response to a predetermined operation. Therefore, even when the telescopic movement of the positioning frame is locked at the intermediate height, the lock can be quickly released by a predetermined operation, and the height adjustment operation of the positioning device can be continued. Also, according to the invention of claim 3, the detent mechanism is configured to be able to lock the telescopic movement of the positioning frame at the intermediate height, the first height, and the second height. Therefore, it can be used both as a fall prevention means for preventing the fall of the positioning device and as a positioning means for positioning the positioning device at the first height and the second height. Also, according to the invention of claim 4, since the fall prevention means is provided only on one of the left and right vertical frame portions, it is possible to handle the operation by one person by performing the unlocking operation of the detent mechanism with one hand and telescoping the positioning frame with the other hand.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIGS. 1 to 4, reference numeral 1 denotes a traveling body of a riding rice transplanter (work vehicle). An implantation work implement 2 is connected to the rear part of the traveling body 1 via a lift link mechanism (not shown) so as to be liftable.

[0009] The traveling body 1 includes an engine mounting portion 3 on which an engine (not shown) is mounted, a transmission case (not shown) that changes the engine power and outputs it as traveling power and working power (the power of the implantation work implement 2), a front wheel 4 that is driven by the traveling power output from the transmission case and is steered in response to an operation of a steering handle S, a rear wheel 5 that is driven by the traveling power output from the transmission case, a control unit 6 on which an operator rides, and a positioning frame 20 in an inverted U shape when viewed from the front and erected at the front of the body.

[0010] A positioning device 30 including GNSS antennas 31, 32, a GNSS unit 33, etc., which are components of the positioning system, is attached to the upper end portion of the positioning frame 20. The positioning system acquires the position information of the traveling body 1 and provides the acquired position information to a position information display device (not shown) and an automatic travel control device (not shown) provided on the traveling body 1. Thereby, the traveling body 1 can display the acquired position information or automatically travel the traveling body 1 based on the acquired position information.

[0011] As a positioning system, for example, an RTK-GNSS positioning system capable of highly accurate positioning with an error of several centimeters is adopted. The RTK-GNSS positioning system performs GNSS positioning such as GPS at each of a fixed base station and a moving mobile station, and corrects positioning data in real time with a correction signal transmitted from the base station to the mobile station, thereby realizing highly accurate positioning with an error of several centimeters. Further, if two GNSS antennas are installed at a predetermined interval on the mobile station, not only the absolute position of the mobile station but also the traveling direction (azimuth) of the mobile station can be detected with high accuracy based on the two positioning results.

[0012] Specifically, the positioning system of the present embodiment includes a reference GNSS antenna 31 and an azimuth GNSS antenna 32 attached to the upper end portion of the positioning frame 20 at a predetermined interval in the left-right direction, and a correction signal receiving device (not shown) that receives a correction signal from a fixed RTK base station (not shown), and a GNSS unit 33 that performs RTK-GNSS positioning based on the GNSS positioning signal and the RTK correction signal. The GNSS unit 33 transmits positioning data (absolute position data and traveling direction data) obtained by RTK-GNSS positioning to a position information display device or an automatic driving control device via a wired communication means such as CAN.

[0013] The positioning frame 20 is formed in a reverse U shape in a front view by left and right vertical frame portions 21 extending upward from the front end portion of the traveling aircraft 1 and a horizontal frame portion 22 connecting the upper end portions of the left and right vertical frame portions 21, and the positioning device 30 is attached to the horizontal frame portion 22. For example, the reference GNSS antenna 31 is attached to one end portion in the left-right direction of the horizontal frame portion 22, the azimuth GNSS antenna 32 is attached to the other end portion in the left-right direction of the horizontal frame portion 22, and the GNSS unit 33 is attached to the middle portion in the left-right direction of the horizontal frame portion 22.

[0014] The left and right vertical frame portions 21 are configured to be telescopically operable in the vertical direction. For example, the vertical frame portion 21 of the present embodiment includes a pipe member 21a extending upward from the front end portion of the traveling body 1, a rod member 21b slidably inserted into the pipe member 21a from above, with the upper end portion connected to the horizontal frame portion 22, a slide fixing mechanism 50 capable of fixing the slide of the rod member 21b at a plurality of positions, and a detent mechanism 60 capable of locking the slide of the rod member 21b at a plurality of positions. Note that the rod member 21b of the present embodiment is formed integrally with the horizontal frame portion 22 by bending a single member, but the rod member 21b and the horizontal frame portion 22 may be separate members and connected by any connecting means.

[0015] The positioning frame 20 can be switched at least between a first posture (see FIGS. 1, 2, and 4) in which the positioning device 30 is positioned at a first height and a second posture (see FIG. 3) in which the positioning device 30 is positioned at a second height lower than the first height in accordance with the telescopic operation of the vertical frame portion 21. Further, the slide fixing mechanism 50 is configured to be able to fix the telescopic movement (slide of the rod member 21b) of the vertical frame portion 21 in the first posture and the second posture. According to such a positioning frame 20, it is possible to adjust the height according to the situation, such as reducing the influence of airframe vibration with the positioning device 30 at the second height or increasing the reception sensitivity with the positioning device 30 at the first height.

[0016] The slide fixing mechanism 50 of the present embodiment includes a pipe-side fixing hole 51 formed in the upper end portion of the pipe member 21a so as to penetrate in the left-right direction, rod-side fixing holes 52 formed in two upper and lower positions of the rod member 21b so as to penetrate in the left-right direction, a fixing pin 53 that can be inserted into the pipe-side fixing hole 51 and the rod-side fixing holes 52, and a retaining pin 54 that prevents the fixing pin 53 from coming out.

[0017] When fixing the positioning frame 20 in the first position, align the pipe-side fixing hole 51 and the lower rod-side fixing hole 52, and insert the fixing pin 53 through both fixing holes 51 and 52. Also, when fixing the positioning frame 20 in the second position, align the pipe-side fixing hole 51 and the upper rod-side fixing hole 52, and insert the fixing pin 53 through both fixing holes 51 and 52. As a result, the vertical frame portion 21 becomes non-extensible and contractible, and the positioning frame 20 is fixed in the first position or the second position.

[0018] The detent mechanism 60 includes a plurality of locking grooves 61A to 61D formed at predetermined intervals in the vertical direction on the rod member 21b, a locking lever 63 provided at the upper end of the pipe member 21a so as to be swingable back and forth via a support shaft 62, an engaging pin 64 provided at the tip of the locking lever 63 and engaging with the locking grooves 61A to 61D, and a return spring 65 that biases the locking lever 63 in a direction in which the engaging pin 64 engages with the locking grooves 61A to 61D.

[0019] According to such a detent mechanism 60, it becomes possible to lock the rod member 21b at a plurality of slide positions by the selective engagement of the engaging pin 64 with the locking grooves 61A to 61D. Also, this locked state is released by swinging the locking lever 63 backward against the biasing force of the return spring 65 (locking release means), and the telescoping operation of the vertical frame portion 21 becomes possible.

[0020] Among the plurality of locking grooves 61A to 61D, the lowermost locking groove 61A is formed at a position corresponding to the first position of the positioning frame 20. That is, when the engaging pin 64 is engaged with the locking groove 61A, the pipe-side fixing hole 51 and the lower rod-side fixing hole 52 are positioned. As a result, the operation of inserting the fixing pin 53 into both fixing holes 51 and 52 becomes easy.

[0021] Among the plurality of locking grooves 61A to 61D, the locking groove 61D formed at the uppermost side is formed at a position corresponding to the second posture of the positioning frame 20. That is, when the engagement pin 64 is engaged with the locking groove 61D, the pipe-side fixing hole 51 and the upper rod-side fixing hole 52 are positioned. Thereby, the insertion operation of the fixing pin 53 into both the fixing holes 51 and 52 becomes easy.

[0022] Among the plurality of locking grooves 61A to 61D, the locking grooves 61B and 61C formed in the middle part are formed to enable the detent mechanism 60 to function as a fall prevention means for the positioning device 30. That is, when the hand is released from the positioning frame 20 during the expansion and contraction operation of the positioning frame 20 (vertical frame portion 21), the positioning device 30 may fall as the positioning frame 20 contracts due to its own weight. However, in the detent mechanism 60 of the present embodiment, the engagement of the engagement pin 64 with the locking groove 61B or the locking groove 61C (automatic engagement by the biasing force of the return spring 65) functions as a fall prevention means for stopping the fall (contraction of the vertical frame portion 21) of the positioning device 30 at an intermediate height between the first height and the second height. Thereby, not only the safety during the expansion and contraction operation of the positioning frame 20 is improved, but also the positioning device 30 can be prevented from being damaged by the impact caused by the fall. Note that the engagement pin 64 may be provided so as not to be rotatable with respect to the locking lever 63, or may be provided so as to be rotatable with respect to the locking lever 63. When the engagement pin 64 is rotatable with respect to the locking lever 63, damage to the rod member 21b due to rubbing against the engagement pin 64 can be reduced.

[0023] In addition, the detent mechanism 60 of the present embodiment is provided only on one of the left and right vertical frame portions 21. In this way, by performing the unlocking operation of the detent mechanism 60 with one hand and expanding and contracting the positioning frame 20 (vertical frame portion 21) with the other hand, even one person can perform the posture switching operation of the positioning frame 20.

[0024] According to the present embodiment configured as described above, the positioning frame 20 is configured to be telescopically operated in the vertical direction, and according to the telescopic operation, at least the first posture for positioning the positioning device 30 at the first height and the first posture for positioning the positioning device 30 at the first height. Since it can be switched to the second posture located at the second height lower than the height, it is possible to reduce the influence of the airframe vibration with the positioning device 30 as the second height, or increase the reception sensitivity with the positioning device 30 as the first height. Thus, height adjustment according to the situation becomes possible.

[0025] Further, the positioning frame 20 includes a fall prevention means (detent mechanism 60) that stops the fall of the positioning device 30 at an intermediate height between the first height and the second height when the hand is released from the positioning frame 20 during the telescopic operation. Therefore, not only the safety during the telescopic operation is improved, but also it is possible to prevent the positioning device 30 from being damaged by the impact associated with the fall.

[0026] Further, the fall prevention means is configured using a detent mechanism 60 that can lock the telescopic movement of the positioning frame 20 at the intermediate height, and the detent mechanism 60 includes a locking release means that releases the locking in response to a predetermined operation. Therefore, even when the telescopic movement of the positioning frame 20 is locked at the intermediate height, the locking can be quickly released by a predetermined operation, and the height adjustment operation of the positioning device 30 can be continued.

[0027] Further, the detent mechanism 60 is configured to be able to lock the telescopic movement of the positioning frame 20 at the intermediate height, the first height, and the second height. Therefore, it can be used both as a fall prevention means for preventing the fall of the positioning device 30 and as a positioning means for positioning the positioning device 30 at the first height and the second height.

[0028] Further, since the detent mechanism 60 is provided only on one of the left and right vertical frame portions 21, it is possible to handle the work alone by operating the locking release of the detent mechanism 60 with one hand and telescoping the positioning frame 20 with the other hand.

Description of Reference Numerals

[0029] 1 Traveling airframe 20 Positioning frame 21 Vertical frame portion 21a Pipe member 21b Rod member 22 Horizontal frame part 30 Positioning device 31 Reference GNSS antenna 32 Azimuth GNSS antenna 33 GNSS unit 50 Slide fixing mechanism 51 Pipe-side fixing hole 52 Rod-side fixing hole 53 Fixing pin 54 Retaining pin 60 Detent mechanism 61A~61D Locking grooves 62 Support shaft 63 Locking lever 64 Engagement pin 65 Return spring

Claims

1. A work vehicle comprising: a traveling body; a positioning device that acquires position information of the traveling body; and a positioning frame in a front view inverted U shape that is erected on the traveling body and supports the positioning device, wherein the positioning frame is configured to be telescopically operated in the vertical direction, and in response to the telescopic operation, at least a first posture in which the positioning device is positioned at a first height and a second posture in which the positioning device is positioned at a second height lower than the first height can be switched; and furthermore, the positioning frame includes a fall prevention means for stopping the fall of the positioning device at an intermediate height between the first height and the second height when the hand is released from the positioning frame during the telescopic operation. The work vehicle is characterized by this.

2. The fall prevention means is configured using a detent mechanism that can lock the telescopic movement of the positioning frame at the intermediate height, and the detent mechanism includes a locking release means for releasing the locking in response to a predetermined operation. The work vehicle according to Claim 1 is characterized by this.

3. The work vehicle according to Claim 2, wherein the detent mechanism is configured to be able to lock the telescopic movement of the positioning frame at the intermediate height, the first height, and the second height.

4. The positioning frame includes: left and right vertical frame portions extending upward from the traveling body; and a horizontal frame portion connecting the upper end portions of the left and right vertical frame portions, the positioning device is attached to the horizontal frame portion, and the height is switched in response to the telescopic operation of the vertical frame portion, and the work vehicle according to Claim 2, wherein the fall prevention means is provided only on one of the left and right vertical frame portions.

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