JP2014147350A - Working device connection structure for riding type working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably connect with a transmission system of a mid-mount type working device by a climbing over and forward movement.SOLUTION: A working device connection structure for a riding type working vehicle comprises an engaging connection mechanism B and a parallel linkage mechanism C. The engaging connection mechanism B is provided so that right and left rear links 24 of a linkage mechanism 22 and right and left auxiliary links 37 adjacent to the linkage mechanism in a back and forth direction are pivotally connected with a car body frame 1, and in accompany with a climbing over and forward movement of right and left front wheels 4 which climb over a mid-mount type working device 21, engaging parts 64 of the respective rear links 24 are guided to engage and connect with parts 45A to be engaged of the working device 21. The parallel linkage mechanism C is provided so that a car body side output shaft 68 engaged with an input shaft 47 of the working device 21 to transmit power or shut off the transmission is rotatably supported by a holder 69, free end parts of the right and left rear links 24 and free end parts of the pair of right and left auxiliary links 37 are connected through the holder 69, and hoisting of the output shaft 68 is allowed while keeping a prescribed fitted attitude of the output shaft 68 with respect to the input shaft 47.

Description

  The present invention relates to a mid-mount type working device disposed between a pair of left and right front wheels and a pair of left and right rear wheels, and a vertical swing provided with a pair of left and right front links and a pair of left and right rear links on a body frame. The power from the power take-off shaft arranged at the rear of the vehicle body is connected via a link mechanism of the type, and the power is supplied from the first universal joint, the relay transmission shaft configured to be stretchable, and the second universal joint. The present invention relates to a work device connection structure for a passenger work vehicle configured to transmit to a rearward input shaft provided in the work device.

  As a work device connection structure for a passenger work vehicle as described above, a mid-mount mower (mid-mount work device) is formed by the left and right front wheels stepping over the front wheel guide plate as the tractor (passenger work vehicle) moves forward. When reaching the abdomen of the tractor, the connecting pins provided at the free ends of the pair of left and right rear links are guided by the openings of the hooks in the pair of left and right support stays provided at the mid-mount mower and reach the innermost part. There is a configuration in which a clutch driving body provided at the rear end of the rear link is fitted to a clutch follower (input shaft) of a mid-mount mower so as to be capable of transmission (see, for example, Patent Document 1).

Japanese Utility Model Publication No.4-110428

  In the above configuration, when connecting the connecting pin of each rear link to the corresponding support stay of the mid-mount mower, the height position of each connecting pin is suitable for connection with the corresponding support stay (Patent Document) 1, after lowering each rear link to its lower limit position so as to be lower than the height position of the opening in each support stay, the left and right front wheels pass over the mower through the upper part of the front wheel guide plate. Go over the tractor and drive forward. Then, the left and right rear links or connecting pins slide in contact with the left and right support stays, etc. as the vehicle travels forward and forward, so that the left and right rear links and connecting pins resist the weight of the left and right support stays, etc. Displacement rises along. When the connecting pin reaches a height position suitable for connection with the corresponding support stay due to this upward displacement, each connection pin is engaged to the innermost part of the opening of the corresponding support stay and is supported. Engage with. In conjunction with this, the clutch driving body provided at the rear ends of the left and right rear links automatically reaches a height position suitable for fitting with the clutch driven body of the mid-mount mower and becomes the clutch driven body. Fits so that transmission is possible.

  By the way, in the technique described in Patent Document 1, a clutch support case that rotatably supports the clutch drive body is provided, and the pair of support pins protruding left and right from the clutch support case have the same height as the left and right connection pins. The clutch drive body is inserted into the connecting pipe fixed in the left-right direction at the rear end of the rear link so as to be positioned, so that the clutch drive body is allowed to change its posture with the pair of support pins as fulcrums. The rear link is provided at the rear end of the rear link.

  That is, in the technique described in Patent Document 1, since the clutch support case is configured to freely change the posture with a pair of support pins as fulcrums, the mid-mount moor is connected by traveling forward. In addition, the posture of the clutch drive body is deviated from the posture suitable for fitting with the clutch follower, and the problem that the clutch drive body does not fit into the clutch follower is easily caused.

  It is an object of the present invention to reliably connect a transmission system to a mid-mount working device by overcoming and traveling forward.

The problem solving means of the present invention is:
An up-and-down swing type link mechanism in which a mid-mount working device arranged between a pair of left and right front wheels and a pair of left and right rear wheels is provided on a body frame with a pair of left and right front links and a pair of left and right rear links. It can be moved up and down via
The power from the power take-out shaft provided at the rear of the vehicle body is transmitted to the rearward input shaft provided in the working device via the first universal joint, the relay transmission shaft configured to be extendable and the second universal joint. Configured as
The vehicle body frame is pivotally connected to the pair of left and right rear links and the pair of left and right auxiliary links that are close to the left and right rear links in the front-rear direction,
The engagement device includes an engagement portion provided at the free end portion of the pair of left and right rear links as the pair of left and right front wheels travels over the work device from behind the work device and travels forward. An engagement coupling mechanism that guides and engages the joint portion;
A holder that rotatably supports the output shaft of the second universal joint that is fitted to the input shaft in an intermittent manner; and the free end portions of the left and right rear links and the pair of left and right auxiliary members via the holder. By connecting the free end portion of the link, a parallel link mechanism that allows the output shaft to move up and down while maintaining the output shaft in a predetermined fitting posture with respect to the input shaft is configured.

  According to this means, for example, the vehicle moves forward in a state where the left and right rear links are lowered to their lower limit positions so that the height position of the engaging portion is lower than the height position suitable for connection with the engaged portion. When running, the left and right rear links and the engaging part are lifted and displaced against their own weight by the action of the engaging and connecting mechanism, and this rising displacement makes the engaging part suitable for connection with the engaged part. If it raises to the height position, an engaging part will engage with an to-be-engaged part with subsequent forward travel.

  Further, when the left and right rear links are moved upward, the output shaft of the second universal joint is moved upward together with the engaging portion while maintaining a predetermined fitting posture by the action of the parallel link mechanism. Reaches a height position suitable for connection with the engaged portion, and the output shaft of the second universal joint reaches a height position suitable for fitting with the input shaft of the work device, and then travels forward. As a result, the engaging portion engages with the engaged portion, and the output shaft of the second universal joint is engaged with the input shaft of the working device so as to be able to transmit.

  As a result, as a preparatory work before traveling forward, the height position of the output shaft of the engaging portion and the second universal joint is connected or fitted to the engaged portion or the input shaft of the working device. It is only necessary to adjust the height position of the output shaft of the engaging portion and the second universal joint so that it is lower than the suitable height position, and it is necessary to accurately adjust the height position suitable for connection or fitting. Since there is no such thing, preparation work before getting over and traveling forward becomes easy.

  Accordingly, it is possible to connect the transmission system to the work device with certainty, as well as the connection of the mid-mount work device by the over-traveling forward travel, while facilitating the preparatory work before performing the forward travel.

As one of the means for making the present invention more suitable,
One of the output shaft and the input shaft is constituted by a cylindrical shaft provided with a diameter-expanding guide portion having a pre-expanded shape that guides the other of them into the interior.

  According to this means, when the output shaft of the second universal joint is fitted to the input shaft of the work device due to the undulation of the ground at the place where the vehicle travels forward and forward, they are displaced in the vertical direction. Even so, one of the output shaft of the second universal joint and the input shaft of the working device can be guided into the other by the guiding action of the diameter expanding guide portion, and the output shaft of the second universal joint can be guided to the working device. It can be fitted to the input shaft so that it can be transmitted.

  Therefore, it is possible to more reliably connect the transmission system to the mid-mount type work device by traveling forward.

It is a left view of a passenger work vehicle. It is a cross-sectional top view of the principal part which shows the connection structure of a mower. It is a left view of the passenger work vehicle which shows the state just before connecting a mower. It is a vertical left view of the principal part which shows the state just before connecting a moor. It is a vertical left view of the principal part which shows the state which connected and grounded the mower. It is the vertical left side view of the principal part which shows the state which connected and moored the mower. It is a vertical left view of the principal part which shows the removal process of a mower.

  Hereinafter, as an example of an embodiment for carrying out the present invention, an embodiment in which a working device connection structure for a passenger work vehicle according to the present invention is applied to a tractor that is an example of a passenger work vehicle will be described with reference to the drawings.

  As shown in FIG. 1, the tractor exemplified in the present embodiment includes a driving portion 2 in the front half of the body frame 1, and forms a boarding operation portion 3 in the rear half of the body frame 1. A front wheel 4 that can be driven to the left and right of the driving unit 2 is provided, and a rear wheel 5 that is a braking wheel that can be braked to the left and right of the riding operation unit 3 to provide a four-wheel drive type. doing.

  The vehicle body frame 1 has a water-cooled diesel engine (hereinafter referred to as an engine) 7 connected to a rear portion of a front frame portion 6, a clutch housing 8 connected to a rear lower portion of the engine 7, and a rear portion of the clutch housing 8. A transmission case (hereinafter referred to as a T / M case) 10 is connected via an intermediate frame portion 9 so as to extend across the tractor.

  The prime mover 2 is configured by disposing an engine 7 and a radiator 12 in an engine room formed by a hood 11. The boarding driver 3 is provided with a steering wheel 13 and a driver seat 14 for front wheel steering.

  The power from the engine 7 is supplied from a hydrostatic continuously variable transmission (hereinafter referred to as HST) connected to the front portion of the T / M case 10 through a main clutch (not shown) provided in the clutch housing 8. This is transmitted to 15 input shafts (not shown). Then, the power from the output shaft (not shown) of the HST 15 is transmitted to a gear type transmission (not shown) provided inside the T / M case 10 for traveling, and the power from the gear type transmission is obtained. Is branched into a front wheel drive and a rear wheel drive inside the T / M case 10. Power for driving the front wheels is transmitted from the inside of the T / M case 10 to the left and right front wheels 4 via a front wheel transmission system (not shown) extending from the left and right front wheels 4. Power for driving the rear wheels is transmitted from the inside of the T / M case 10 to the left and right rear wheels 5 via a rear wheel transmission system (not shown) extending from the left and right rear wheels 5. On the other hand, the power from the input shaft of the HST 15 is rearward provided at the rear end portion of the T / M case 10 via a work transmission system (not shown) provided inside the T / M case 10 for working. The first power take-off shaft 16 and the forward second power take-out shaft 17 provided at the bottom of the T / M case 10 are transmitted.

  As shown in FIGS. 1 and 3, at the rear of the T / M case 10, a pair of left and right lift arms 18 that swing up and down by the operation of a lift cylinder (not shown) provided therein, and these A first link mechanism 19 that moves up and down in conjunction with the vertical swing of the lift arm 18 is provided. A single acting hydraulic cylinder is adopted as the lift cylinder. The first link mechanism 19 includes a pair of left and right lower links 20 that enable attachment and detachment of a working device (not shown) such as a rotary tiller or a plow.

  That is, by connecting and equipping the first link mechanism 19 with a working device such as a rotary tiller or a plow, the working device can be installed at the rear of the tractor so that it can be raised and lowered by operating the lift cylinder. Can do. And when the working device is a drive type operated by power from a tractor, such as a rotary tiller, an input shaft (not shown) of the working device is used as an external transmission shaft (not shown). By connecting to the first power take-off shaft 16 via the above, the working power taken out from the first power take-out shaft 16 can be transmitted to the work device to operate the work device.

  Although not shown, the lift cylinder is a supply state in which a switching valve that switches the flow of oil to the lift cylinder based on the operation of the lifting lever provided in the boarding operation unit 3 supplies oil from the hydraulic pump to the lift cylinder. Is switched to the extended state in which the working device is raised by the oil from the hydraulic pump. When the switching valve is switched to a discharge state in which the oil in the lift cylinder is discharged based on the operation of the lifting lever, the switching valve is switched to a contracted state in which the working device is lowered due to the weight of the working device. Based on the operation of the lift lever, when the switching valve is switched to a supply / discharge stop state in which oil supply / discharge to / from the lift cylinder is stopped, the switching valve is switched to an expansion / contraction stop state in which the working device is stopped to move up and down.

  As shown in FIGS. 1 to 6, the lower abdomen (hereinafter referred to as the lower abdomen of the tractor) between the left and right front wheels 4 and the left and right rear wheels 5 of the tractor is an example of a mid-mount working device. A mid-mount mower (hereinafter referred to as mower) 21 is equipped. Between the vehicle body frame 1 and the mower 21, a second link mechanism 22 that supports the mower 21 so as to be lifted and lowered is interposed. The second link mechanism 22 includes a pair of left and right front links 23 extending from the front of the vehicle body frame 1 to the front end of the mower 21 in a rearward downward tilt posture, and the mower 21 from the front and rear intermediate portion of the vehicle body frame 1 in a rearward downward tilt posture. A pair of left and right rear links 24 and the like extending across the rear part are provided, and the mower 21 is configured in a parallel link type that moves up and down in a predetermined mowing posture. The left and right rear links 24 are linked to the left and right lower links 20 of the first link mechanism 19 via a linkage mechanism 25.

  The linkage mechanism 25 is a pair of left and right rotating shafts 26 that are mounted on the vehicle body frame 1 so as to be rotatable, and a pair of left and right mounted integrally on the rotating shaft 26 in a state of extending from the rotating shaft 26 toward the front of the vehicle body. One linkage arm 27, a pair of left and right second linkage arms 28 integrally mounted on the pivot shaft 26 in a state of extending from the pivot shaft 26 toward the upper side of the vehicle body, and a pair of left and right provided on the rear portion of the T / M case 10. A pair of left and right first linkage rods 30 that link the interlocking arm 29, the left and right first linkage arms 27 to the free end side of the corresponding rear link 24, and a pair of left and right second linkage arms 28 are linked to the corresponding linkage arms 29. And a pair of left and right second linkage rods 31. The left and right interlocking arms 29 are externally fitted to the support shaft 32 of the corresponding lower link 20 so as to be capable of relative swinging. At the upper part of the left and right interlocking arms 29, an abutting piece 29A that contacts one side from above is bent at the upper edge of the corresponding lower link 20 of the first link mechanism 19 due to the weight of the left and right rear links 24, and the like.

  That is, the mower 21 is connected to the vehicle body frame 1 via the second link mechanism 22, and the second link mechanism 22 is linked to the first link mechanism 19 via the linkage mechanism 25. The lower abdomen of the tractor is equipped to move up and down.

  As shown in FIGS. 1 and 3 to 6, the rotating shaft 26 is integrally provided with a single third linkage arm 33 extending toward the rear of the vehicle body. The intermediate frame portion 9 of the vehicle body frame 1 receives the third linkage arm 33 that swings up and down in conjunction with the downward swing of the left and right rear links 24, thereby preventing the left and right rear links 24 from swinging downward. A receiving device 34 is provided. The receiving device 34 includes a gripping portion 34A that can be rotated around the vertical axis from the boarding operation unit 3, and a cylindrical receiving portion 34B that rotates integrally with the gripping portion 34A around the vertical axis. Etc. And the lower edge of the receiving part 34B which receives the 3rd linkage arm 33 is formed in the step shape from which height differs in the circumferential direction.

  With this configuration, the holding height position of the third linkage arm 33 by the receiving tool 34 can be arbitrarily determined by holding the holding part 34A from the boarding operation unit 3 and rotating the receiving tool 34 about the longitudinal axis. The lower limit position of the left and right rear links 24 relative to the vehicle body frame 1 (hereinafter referred to as the lower limit position of the rear links 24) can be easily changed.

  That is, the lower limit height of the mower 21 relative to the vehicle body frame 1 by changing the setting of the lower limit position of the left and right rear links 24 by the third linkage arm 33 and the catch 34 (hereinafter referred to as the lower limit height of the mower 21). A lower limit setting mechanism 35 is set.

  As described above, in the linkage mechanism 25 that links the left and right rear links 24 to the left and right lower links 20, the contact pieces 29A of the left and right interlocking arms 29 are separated from the upper edge of the corresponding lower links 20 from above. In the lower limit setting mechanism 35, the lower link setting mechanism 35 is configured to receive the third linkage arm 33 that swings upward and downward by a receiving device 34 disposed above the lower link setting mechanism 35. When the mower 21 equipped on the vehicle rides on a partially raised portion or the like of the work site, the ascent displacement of the mower 21 due to the upward swing of the second link mechanism 22 with respect to the vehicle body frame 1 can be allowed. Even in the state where the lowering and swinging of the left and right rear links 24 is prevented by the receiving member 34, the left and right lower links 20 can be lowered and swung by the operation of the lift cylinder.

  As shown in FIGS. 1 to 6, the mower 21 includes a corresponding vertical rotation shaft 36 and three blades (not shown) that rotate integrally clockwise in plan view, and a mower deck that covers these blades from above. 38, etc. On the upper part of the mower deck 38, a transmission mechanism 39 for driving the blade is provided. In addition, left and right transmission covers 40 that cover the left and right ends of the transmission mechanism 39 from above are detachably attached. The mower deck 38 is configured such that the front upper portion 38A is formed so as to bulge upward across the left and right of the mower deck 38, so that the interior of the front upper portion 38A can be used as a conveying path 38B for mowing grass. A discharge port 38C is formed at the right end of the mower deck 38, which is the end of the transport path 38B, and a discharge cover 41 is provided.

  That is, the mower 21 discharges the grass cut by the three blades to the outside from the discharge port 38C on the right end through the transport path 38B of the front upper portion 38A in the mower deck 38 by the transport wind generated as each blade rotates. The side discharge specification is configured.

  The mower deck 38 is provided with a gauge wheel 42 whose height can be adjusted at both left and right end portions of the rear portion. In addition, guide rollers 43 are provided at the front left and right center locations and the left and right end locations. The left and right front links 23 are pivotally connected to a pair of left and right first brackets 44 that support the left and right center guide rollers 43 so as to be vertically swingable. At the rear of the moor deck 38, a second bracket 45 as a pair of left and right engaging members that enables engagement with the free end portions of the left and right rear links 24 pivotally connected to the body frame 1 so as to be swingable up and down. Is standing.

  The transmission mechanism 39 interlocks and connects the input shaft 47 extending rearward from the transmission case 46 disposed in the center of the mower deck 38, and the rotation shaft 36 disposed in the center of the mower deck 38 inside the transmission case 46 and the input shaft 47. A pair of bevel gears (not shown), a driving pulley 48 that rotates integrally with the central rotating shaft 36, left and right driven pulleys 49 that rotate integrally with the left and right rotating shafts 36 disposed on both left and right sides of the mower deck 38, and a driving pulley 48 A tension pulley 50 disposed behind the transmission pulley 50, a transmission belt 51 wound around the pulleys 48 to 50, and the like, and by transmitting the power transmitted to the input shaft 47 to each rotary shaft 36, A belt transmission type is configured to rotate each blade together with the rotating shaft 36 clockwise in plan view.

  The input shaft 47 of the transmission mechanism 39 receives power from the second power take-out shaft 17 of the tractor via the first universal joint 52, the relay transmission shaft 53 configured to be extendable, the second universal joint 54, and the like. Is communicating.

  The left and right transmission covers 40 are provided in a state having a high strength that allows the front wheel 4 to get over at a front wheel overrunning portion of the mower deck 38 in order to allow the left and right front wheels 4 to get over the mower 21. Further, when mounted on the mower deck 38, the upper surface of the front upper portion 38A of the mower deck 38 and the upper surfaces of the transmission covers 40 are configured to have substantially the same height.

  With this configuration, when the mower 21 is positioned on the lower abdomen of the tractor, the left and right front wheels 4 pass over the corresponding transmission cover 40 from the rear of the moor 21 and advance over the tractor so that the tractor moves forward. By running, the mower 21 is simply arranged on the lower abdomen of the tractor without the need to push the mower 21 between the left and right front wheels 4 and the left and right rear wheels 5 from the lateral side of the tractor. be able to.

  On the other hand, when the mower 21 is taken out from the lower abdomen of the tractor, the left and right front wheels 4 pass over the corresponding transmission cover 40 from the front of the moor 21 and ride over the reverse so that the tractor moves backward. By doing so, it is possible to easily remove the mower 21 from the lower abdomen of the tractor without having to take out the mower 21 from between the left and right front wheels 4 and the left and right rear wheels 5 to the lateral outside of the tractor. .

  A reinforcing member 55 that also serves as a guide plate for guiding the corresponding front wheel 4 across the front and rear ends of the transmission cover 40 is welded to the inner end portion of the upper surface of each transmission cover 40. Thereby, while increasing the strength of the left and right transmission covers 40, it is possible to suppress the occurrence of inconvenience that the left and right front wheels 4 are displaced in the left and right directions with respect to the left and right transmission covers 40 when getting over the mower 21. it can.

  As shown in FIG. 2, the moor deck 38 has a flat anti-slip member 56 attached to a front portion of the left and right transmission covers 40 in the front upper portion 38 </ b> A. As a result, when the vehicle travels over the tractor and moves forward, the left and right anti-slip members 56 can be used as an index, and the vehicle can travel forward and travel more easily and appropriately. Further, the sliding of the front wheels 4 with respect to the mower deck 38 that may occur when the left and right front wheels 4 get on and off the front portion 38A of the mower deck 38 can be suppressed. It is possible to avoid the possibility of being pushed out.

  As shown in FIGS. 1 to 6, in the second link mechanism 22, the left and right front links 23 connect their front end portions, which are free end portions, via a left and right connecting shaft 57. And it is comprised so that engagement connection with the front-end part of the vehicle body frame 1 via the connection shaft 57 is attained. Further, between the left front link 23 and the left first bracket 44, the left and right front links 23 are returned and urged to a connecting posture in which the left and right front links 23 are inclined upwardly from the mower 21 by a predetermined angle. An urging means 58 for maintaining 57 at a predetermined height position is interposed. The biasing means 58 includes an upper spring receiving portion 23A provided on the left front link 23, a rod 59 that is pivotably connected to the left first bracket 44 in a state of passing through the upper spring receiving portion 23A, and The compression spring 60 is externally fitted to the rod 59 so as to be positioned between the upper spring receiving portion 23A and the lower spring receiving portion 59A provided in the rod 59.

  On the other hand, the front end portion of the vehicle body frame 1 functions as an engagement member that engages with the connecting shaft 57 of the second link mechanism 22 from the rear as the left and right front wheels 4 travel forward after the mower 21 is passed. A pair of left and right brackets 61 formed as described above is suspended. Each bracket 61 is formed with a recess 61A as an engaging portion that is recessed backward from the front end thereof. Further, on the front side of each recess 61A, upper and lower guide portions 61a and 61b for guiding the connecting shaft 57 to an appropriate height as the vehicle travels forward, and a receiving portion 61c for receiving the connecting shaft 57 having an appropriate height. It has.

  That is, the left and right brackets 61 on the tractor side and the connecting shaft 57 on the mower side cause the connecting shafts 57 to be recessed in the respective brackets 61 as the left and right front wheels 4 travel forward from the rear of the moor 21 over the mower 21. A first engagement connection that engages and connects the free end portions of the left and right front links 23 on the mower side to a predetermined position of the vehicle body frame 1 by engaging and guiding 61A to reach the receiving portion 61c at the rear end of the recess. Mechanism A is configured.

  As shown in FIGS. 1 to 7, left and right support shafts 62 that extend to the left and right rear links 24 are provided at the rear ends of the left and right rear links 24. The support shaft 62 passes through the rear end portions of the left and right rear links 24 in a rotatable manner. The left and right end portions of the support shaft 62 projecting laterally outward from the left and right rear links 24 are engaged and connected between the free end portions of the left and right rear links 24 and the left and right second brackets 45 provided in the mower 21. It is comprised so that it may function as the engaging pin 64 which is an engaging part which enables this.

  On the other hand, the left and right second brackets 45 are formed with recesses 45 </ b> A as engaged portions that enable engaging connection with the free ends of the left and right rear links 24. The recess 45A is formed in the upper part of each second bracket 45 so as to be recessed forward from the rear end of the second bracket 45 to allow the engagement pin 64 to be engaged from behind. In addition, a guide portion 45B is formed at the rear end of each second bracket 45 to guide the engaging pin 64 corresponding to the time when the vehicle travels forward and travels to the recess 45A.

  That is, the left and right engagement pins 64 are moved by the tractor-side support shaft 62 and the mower-side left and right second brackets 45 as the left and right front wheels 4 move forward from the rear of the mower 21 and move forward. The engaging end of the left and right rear links 24 on the tractor side is engaged with and connected to a predetermined position of the mower 21 by engaging and guiding the corresponding recessed portion 45A of the second bracket 45 to reach the front end portion of the recessed portion 45A. A two-engagement coupling mechanism B is configured.

  Each second bracket 45 is equipped with a lock mechanism 65 that maintains the free end portions of the left and right rear links 24 and the left and right second brackets 45 in an engaged and connected state. Each lock mechanism 65 includes a lock arm 66 connected to the second bracket 45 so as to be swingable up and down, and a tension spring 67 that urges the lock arm 66 to return to the lock posture. The lock arm 66 is in a locked posture such that the lock arm 66 resists the biasing force of the tension spring 67 by the contact of the engagement pin 64 with respect to the engagement pin 64 that is engaged toward the front end portion of the recess 45A. By swinging downward, the engagement pin 64 is allowed to be engaged with the front end portion of the recess 45A, and for the engagement pin 64 engaged with the front end portion of the recess 45A, By receiving the engagement pin 64 at the front end of the lock arm 66, the engagement pin 64 is set to a forward rising inclination posture so as to be held at the front end portion of the recess 45A.

  As shown in FIGS. 1 to 6, a pair of left and right auxiliary links 37 are not overlapped with the left and right rear links 24 in the front and rear direction view at the rear portion of the left and right rear links 24 in the body frame 1. It is pivotally connected so as to be close to each other in the front-rear direction while being displaced in the left-right direction. At the free ends of the left and right auxiliary links 37, a left and right support shaft 63 spans the left and right auxiliary links 37, and the distance from the swing fulcrum of the left and right auxiliary links 37 to the support shaft 63 is It is provided in a state set to be the same as the distance from the swing fulcrum to the support shaft 62. The support shaft 63 passes through the free end portions of the left and right auxiliary links 37 in a rotatable manner. A holder 69 for supporting the output shaft 68 provided in the output portion 54A of the second universal joint 54 is installed over the support shaft 63 and the support shaft 62 on the rear link side located in front of the support shaft 63.

  The output shaft 68 of the second universal joint 54 is constituted by a cylindrical shaft that is spline-fitted to the input shaft 47 of the mower 21 in an intermittent manner. A front-end portion that is a fitting start end portion of the mower 21 with respect to the input shaft 47 is provided with a diameter-expanding guide portion 68A having a pre-expanded shape that guides the input shaft 47 of the mower 21 to the inside. Further, the extension length from the holder 69 to the front is that before the left and right engaging pins 64 are engaged with the corresponding recesses 45A of the second bracket 45 when the mower 21 is mounted by overcoming forward traveling. The enlarged diameter guide portion 68 </ b> A is configured to have a length that fits around the input shaft 47 of the mower 21.

  The holder 69 supports the output shaft 68 of the second universal joint 54 via the bearing 70 so as to be rotatable and non-slidable. In addition, the center-to-center distance between the first fitting hole 69a that allows external fitting to the support shaft 62 on the rear link side and the second fitting hole 69b that enables external fitting to the support shaft 63 on the auxiliary link side. However, the distance between the centers of the swing fulcrum of the rear link 24 and the swing fulcrum of the auxiliary link 37 is the same. Furthermore, the vertical center distance between the first fitting hole 69 a and the bearing 70 is the vertical distance between the vertical intermediate position of the recess 45 </ b> A of each second bracket 45 and the axis of the input shaft 47 in the mower 21. It is configured to be the same.

  That is, by connecting the free end portions of the left and right rear links 24 and the free end portions of the left and right auxiliary links 37 via the support shafts 62 and 63 and the holder 69, the output shaft 68 of the second universal joint 54 is connected. While maintaining the fitting posture of the moor 21 in the front-rear direction with respect to the input shaft 47, the vertical separation distance between the left and right engaging pins 64 and the output shaft 68 of the second universal joint 54 is set to each second in the moor 21. A parallel link mechanism C that allows the output shaft 68 to move up and down while maintaining the same distance as the vertical distance between the concave portion 45A of the bracket 45 and the input shaft 47 is configured.

  When the mower 21 is mounted on the lower abdomen of the tractor from the above configuration, first, the height positions of the respective engagement pins 64 provided at the free ends of the left and right rear links 24 are set to the left and right provided to the mower 21. The lower limit setting mechanism 35 is operated to change the lower limit position of the left and right rear links 24 so that the height of the second bracket 45 can be made lower than the height position suitable for the connection with the recess 45A.

  Next, the left and right rear links are operated by operating the elevating lever so that the height position of each engagement pin 64 is lower than the height position suitable for engagement with the corresponding recess 45A of the second bracket 45. Lower the dead weight to the lower limit position.

  When the above-described overriding traveling is performed in this state, the left and right rear links 24 or the engaging pins 64 slide on the left and right second brackets 45 as the left and right front wheels 4 get over the mower 21. Thus, the left and right rear links 24 and the engagement pins 64 are displaced upwardly along the left and right second brackets 45 and the like by their action of the second engagement connecting mechanism B and the like. Further, due to the action of the parallel link mechanism C, the output shaft 68 of the second universal joint 54 is displaced upward while maintaining the fitting posture in the front-rear direction.

  Thereafter, when the left and right front wheels 4 get over the mower 21, the left and right engagement pins 64 reach a height position suitable for engagement with the corresponding recess 45 </ b> A of the second bracket 45 with the subsequent forward travel. At the same time, the output shaft 68 of the second universal joint 54 reaches a height position suitable for fitting with the input shaft 47 of the mower 21 in a fitting posture in the front-rear direction.

  As the vehicle travels forward after the arrival, the left and right engaging pins 64 push down the lock arm 66 of the corresponding lock mechanism 65 against the urging force of the tension spring 67, and the corresponding second bracket 45. The recess 45 </ b> A is engaged from behind, and the output shaft 68 of the second universal joint 54 is externally fitted to the input shaft 47 of the mower 21 from behind.

  Thereafter, when the left and right engaging pins 64 reach the front end portions of the corresponding recesses 45 </ b> A of the second bracket 45, the lock arms 66 of the respective lock mechanisms 65 return to the locked posture by the urging of the tension springs 67. Then, by receiving the corresponding engagement pin 64 from the rear lower side by the front end, the corresponding engagement pin 64 is prevented from being detached from the front end portion of the recess 45 </ b> A of the second bracket 45. Further, by preventing the separation, the output shaft 68 of the second universal joint 54 is externally fitted so as to be able to transmit to the input shaft 47 of the mower 21 (spline-fitted state).

  Also, if the output shaft 68 of the second universal joint 54 is externally fitted to the input shaft 47 of the mower 21 due to the undulation of the ground at the place where the vehicle travels forward and travels, they are displaced in the vertical direction. Even if it does, the input shaft 47 of the mower 21 can be fitted and guided to the inside of the output shaft 68 while absorbing the positional deviation by the guiding action of the diameter expansion guide portion 68A. The output shaft 68 can be externally fitted to the input shaft 47 of the mower 21 so as to be able to transmit.

  In other words, by performing the above-mentioned traveling forward movement, the free end portions of the left and right rear links 24 can be easily and reliably engaged and connected to the left and right second brackets 45 of the mower 21, and the tractor side The output shaft 68 can be easily and reliably connected to the input shaft 47 of the mower 21 so as to be able to transmit power, and the connected state and the connected state can be maintained.

  On the other hand, at the front end portion of the tractor, when the left and right front wheels 4 get over the mower 21, the mower side connecting shaft 57 is moved to the tractor side by the action of the first engagement connecting mechanism A described above during the forward traveling. It engages with the recess 61A of the left and right brackets 61 and reaches the receiving portion 61c at the rear end of the recess. Thus, the free end portions of the left and right front links 23 on the mower side including the connecting shaft 57 can be engaged and connected to the left and right brackets 61 (predetermined positions on the vehicle body frame 1) on the tractor side. This engagement connection can be maintained by the lock mechanism 65 maintaining the state where the free end portions of the left and right rear links 24 are connected to the left and right second brackets 45 of the mower 21 by its action.

  In short, by performing the above-mentioned traveling forward and overcoming, the mower 21 can be easily and surely connected to the lower abdomen of the tractor so that it can be lifted and lowered, and the transmission system is easily and reliably connected to the mower 21. Can be done.

  As shown in FIGS. 1, 2, and 7, the lock arm 66 of each lock mechanism 65 includes a linkage pin 66 </ b> A that protrudes laterally outward at the front end portion thereof. The boarding operation unit 3 is provided with a release pedal 71 that enables the left and right lock mechanisms 65 to be released from the boarding operation unit 3. The release pedal 71 swings up and down about a left and right support shaft 72 provided on the vehicle body frame 1, and contacts a stopper 74 provided on the vehicle body frame 1 by the action of a torsion spring 73 fitted on the support shaft 72. It is configured to automatically return to the stepping release position that touches it. The support shaft 72 is equipped with left and right linkage arms 75 that swing together with the release pedal 71 via the support shaft 72. The left and right linkage arms 75 are L-shaped in a side view and are arranged so as to swing up and down at the free ends of the left and right rear links 24 via left and right release wires 76 routed along the left and right rear links 24. The operation arm 77 is linked. In a state where the release pedal 71 is located at the depression release position, the left and right operation arms 77 are separated upward from the link pins 66A of the corresponding lock arm 66 by the action of the corresponding torsion spring 78, and the left and right tension springs 67 The lock pins 66A of the corresponding lock arm 66 are allowed to resist the action of the corresponding torsion spring 78 in conjunction with the depression operation of the release pedal 71 while allowing the lock arms 66 to return to the locked posture by urging. Is pressed from above, and the left and right lock arms 66 are switched from the locked position to the unlocked position against the bias of the tension spring 67.

  In other words, by depressing the release pedal 71, the lock mechanism 65 releases the maintenance connection state between the free end portions of the left and right rear links 24 on the tractor side and the left and right second brackets 45 on the mower side. can do. As a result, the moor side connecting shaft 57 is disengaged from the recess 61A of the left and right brackets 61 on the tractor side and the left and right rear sides of the tractor side from the recess 45A of the left and right second bracket 45 on the tractor side due to reverse travel The disengagement of the engagement pin 64 of the link 24 and the disengagement of the output shaft 68 on the tractor side from the input shaft 47 of the mower 21 can be permitted.

  Accordingly, when the mower 21 is removed from the lower abdomen of the tractor, first, the elevating lever is operated to the lowered position, and the mower 21 is lowered by its own weight to be grounded. Next, after depressing the release pedal 71 to release the lock by each lock mechanism 65 and performing the above-described overriding backward traveling, the first traveling by the backward traveling until the left and right front wheels 4 ride on the mower 21 is performed. Engagement connection between the left and right brackets 61 on the tractor side by the engagement connection mechanism A and the connection shaft 57 on the mower side, and a free end portion of the left and right rear links 24 on the tractor side by the second engagement connection mechanism B and the mower side The engagement connection with the left and right second brackets 45 and the spline fitting between the output shaft 68 on the tractor side and the input shaft 47 of the mower 21 can be easily released. Then, when the left and right front wheels 4 get over the mower 21 by the subsequent reverse travel, the mower 21 can be easily taken out from the lower abdomen of the tractor.

  [Another embodiment]

[1] The riding work vehicle may be a riding mower configured so that the mid-mount mower 21 can be attached and detached. Also, a mower dedicated hydraulic lifting mechanism, or a mower dedicated manual lifting mechanism that manually lifts and lowers the mower 21 may be provided.

[2] The mid-mount working device 21 may be a grass collecting device configured to be able to ride over the left and right front wheels 4.

[3] The mid-mount mower 21 may be configured to have a rear discharge specification in which the cut grass is discharged rearward from a discharge port formed at the rear end of the mower. The grass cut by the blade may flow in the mower deck 38 and chopped, and then fallen to the ground below from the bottom opening of the mower deck 38. Further, the number of blades provided in the mid-mount mower 21 and the transmission structure for the blades can be variously changed.

[4] The pair of left and right auxiliary links 37 may be arranged close to the front side of the left and right rear links 24.

[5] As the engagement connecting mechanism B, a concave portion formed so as to be recessed backward from the front side to the free end portion of the left and right rear links 24 becomes an engaging portion 64, and the concave portion can be engaged from the front. The left and right engaging pins provided in the work device 21 may be configured to be the engaged portion 45A.

[6] The input shaft 47 of the work device 21 may be constituted by a cylindrical shaft provided with a diameter-expanding guide portion having a pre-expanded shape that guides the output shaft 68 on the tractor side.

[7] Regarding the connection of the work device 21, the output of the engaging portion 64 provided in the left and right rear links 24 and the output of the second universal joint 54 provided in the parallel link mechanism C in the stage before overcoming and traveling forward. The raising / lowering operation of the link mechanism 22 may be performed in advance so that the shaft 54A is located at a height position suitable for connection with the engaged portion 45A or the input shaft 47 provided in the work device 21.

  The working device connection structure for a passenger work vehicle according to the present invention is applied to a passenger work vehicle such as a tractor or a riding mower that is detachably provided with a mid-mount working device configured to be able to ride over the left and right front wheels. Can do.

DESCRIPTION OF SYMBOLS 1 Body frame 4 Front wheel 5 Rear wheel 17 Power take-out shaft 21 Working device 22 Link mechanism 23 Front link 24 Rear link 37 Auxiliary link 45A Engagement part 47 Input shaft 52 First universal joint 53 Relay transmission shaft 54 Second universal joint 64 Engagement section 68 Output shaft 68A Diameter expansion guide section 69 Holder B Engagement connection mechanism C Parallel link mechanism

That is, in the technique described in Patent Document 1, since the clutch support case is configured to freely change the posture with the pair of support pins as fulcrums, when the mid-mount mower is connected by forward traveling , Therefore, the clutch drive body is likely to be out of the posture suitable for fitting with the clutch follower and the clutch drive body is not fitted into the clutch follower.

An object of the present invention is to reliably connect a transmission system to a mid-mount working device by forward traveling .

The problem solving means of the present invention is:
An up-and-down swing type link mechanism in which a mid-mount working device arranged between a pair of left and right front wheels and a pair of left and right rear wheels is provided on a body frame with a pair of left and right front links and a pair of left and right rear links. It can be moved up and down via
The power from the power take-out shaft provided at the rear of the vehicle body is transmitted to the rearward input shaft provided in the working device via the first universal joint, the relay transmission shaft configured to be extendable and the second universal joint. Configured as
The vehicle body frame is pivotally connected to the pair of left and right rear links and the pair of left and right auxiliary links that are close to the left and right rear links in the front-rear direction,
An engagement portion provided at the free end portion of the pair of left and right rear links in association with the forward traveling for connection after the work device is disposed between the pair of left and right front wheels and the pair of left and right rear wheels. An engagement connecting mechanism that guides and engages an engaged portion provided in the working device;
And a free end portion of the right and left pair of auxiliary links and the free end portion of the link after the pair linked via a lower link, and the lower link, wherein the intermittently allow fitted to the input shaft A parallel link mechanism that allows the output shaft to move up and down while maintaining the output shaft in a predetermined fitting posture with respect to the input shaft by fixedly mounting a shaft support portion that rotatably supports the output shaft of the universal joint. Configured.

According to this means, for example, for connection in a state where the right and left rear links are lowered to their lower limit positions so that the height position of the engaging portion is lower than the height position suitable for connection with the engaged portion . When the forward traveling is performed, the left and right rear links and the engaging portion are lifted and displaced against their own weight by the action of the engaging and connecting mechanism, and the engaging portion is connected to the engaged portion by this rising displacement. If it raises to the height position suitable for, an engaging part will engage with an to-be-engaged part with subsequent forward travel.

Thus, as a preparatory work before the forward traveling for connection, the height position of the output shaft of the engaging portion and the second universal joint is connected or fitted to the engaged portion or the input shaft of the work device. It is only necessary to adjust the height position of the output shaft of the engaging portion and the second universal joint so that it is lower than the height position suitable for the joint, and accurately adjust to the height position suitable for connection or fitting Since it is not necessary to do this, the preparatory work before the forward traveling for connection is facilitated.

Therefore, while making the preparatory work before performing the forward traveling for the connection easy, it is possible to reliably connect the transmission system to the working device together with the connection of the mid-mount type work device by the forward traveling for the connection.

According to this means, when the output shaft of the second universal joint is fitted to the input shaft of the work device due to the undulation of the ground at the place where the forward traveling for connection is performed, they are displaced in the vertical direction. Even if it does, one of the output shaft of the second universal joint and the input shaft of the working device can be guided into the other by the guiding action of the diameter expansion guide portion, and the output shaft of the second universal joint can be The input shaft of the working device can be fitted so as to be able to transmit.

Therefore, it is possible to more reliably connect the transmission system to the mid-mount work device by the forward traveling for connection.

As shown in FIGS. 1 to 6, a pair of left and right auxiliary links 37 are not overlapped with the left and right rear links 24 in the front-rear direction view at the rear portion of the left and right rear links 24 in the vehicle body frame 1. It is pivotally connected so as to be close to each other in the front-rear direction while being displaced in the left-right direction. At the free ends of the left and right auxiliary links 37, a left and right support shaft 63 spans the left and right auxiliary links 37. The distance from the swing fulcrum of the left and right auxiliary links 37 to the support shaft 63 is the distance between the left and right rear links 24. It is provided in a state set to be the same as the distance from the swing fulcrum to the support shaft 62. The support shaft 63 passes through the free end portions of the left and right auxiliary links 37 in a rotatable manner. A holder 69 for supporting the output shaft 68 provided in the output portion 54A of the second universal joint 54 is installed over the support shaft 63 and the support shaft 62 on the rear link side located in front of the support shaft 63. The holder 69 has a pair of left and right lower links 69A across the front and rear support shafts 62 and 63, and a shaft support portion 69B that supports the output shaft 68 is fixedly mounted in a state of being spanned between the left and right lower links 69A. .

DESCRIPTION OF SYMBOLS 1 Body frame 4 Front wheel 5 Rear wheel 17 Power take-out shaft 21 Working device 22 Link mechanism 23 Front link 24 Rear link 37 Auxiliary link 45A Engagement part 47 Input shaft 52 First universal joint 53 Relay transmission shaft 54 Second universal joint 64 Engagement section 68 Output shaft 68A Diameter expansion guide section
69A bottom link
69B shaft support B engagement coupling mechanism C parallel link mechanism

Claims (2)

An up-and-down swing type link mechanism in which a mid-mount working device arranged between a pair of left and right front wheels and a pair of left and right rear wheels is provided on a body frame with a pair of left and right front links and a pair of left and right rear links. It can be moved up and down via
The power from the power take-out shaft provided at the rear of the vehicle body is transmitted to the rearward input shaft provided in the working device via the first universal joint, the relay transmission shaft configured to be extendable and the second universal joint. Configured as
The vehicle body frame is pivotally connected to the pair of left and right rear links and the pair of left and right auxiliary links that are close to the left and right rear links in the front-rear direction,
The engagement device includes an engagement portion provided at the free end portion of the pair of left and right rear links as the pair of left and right front wheels travels over the work device from behind the work device and travels forward. An engagement coupling mechanism that guides and engages the joint portion;
A holder that rotatably supports the output shaft of the second universal joint that is fitted to the input shaft in an intermittent manner; and the free end portions of the left and right rear links and the pair of left and right auxiliary members via the holder. A work device connection for a passenger work vehicle that forms a parallel link mechanism that allows the output shaft to move up and down while maintaining the output shaft in a predetermined fitting posture with respect to the input shaft by connecting the free end portion of the link. Construction.   The working device connection structure of a passenger work vehicle according to claim 1, wherein one of the output shaft and the input shaft is constituted by a cylindrical shaft provided with a diameter-expanding guide portion having a widening shape that guides the other of the output shaft and the other into the interior. .

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