JP2015126705A - Mid-mount type mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mid-mount type mower which enables the connection of a mower unit to a machine body without causing structural limitations to a conventional lift link mechanism.SOLUTION: A mid-mount type mower equipped with a mower unit 4 between a front wheel 2a and a rear wheel 2b under a machine body 1 comprises: a lift link mechanism 3 including a front link 31 and a rear link 32; an intermediate structure 6 for connecting one end of the front link 31 and one end of the rear link 32 through a swing shaft core; a blade housing 40 provided with an engaged part 620 that can be engaged with an engaging part 610 of the intermediate structure 6; and a guide surface 630 for guiding the engaging part 610 and the engaged part 620 to the engaging position so as to connect the blade housing 40 placed on a ground surface and the intermediate structure 6 in accordance with the movement of the machine body 1 in a back-and-forth direction.

Description

  The present invention relates to a mid-mount mower equipped with a mower unit between a front wheel and a rear wheel below a fuselage.

  In the mid-mount mower, a blade housing that covers a rotating blade is connected to a lifting / lowering link mechanism including a front link and a rear link that are provided in the airframe with a space in the longitudinal direction of the airframe. Thereby, the blade housing can be raised and lowered between the lowered working position and the raised non-working position. The mower unit is removed from the airframe during maintenance and inspection of the mower unit or when performing work other than mowing. It is very burdensome to perform connecting / disconnecting work in a narrow space between the front wheel and the rear wheel. For this reason, it has been proposed previously to automatically perform at least some of the steps in the connection / disconnection operation.

  For example, in the mid-mount mower described in Patent Document 1, the blades are positioned on the abdomen of the tractor by using the front wheel guide plates of the blade housing by moving the aircraft forward. By stepping over the housing and finally moving forward, the connecting pins provided at the free ends of the pair of left and right rear links are guided to the openings of the hook portions of the pair of left and right support stays provided at the blade housing. Go into the back. Next, the lock arm provided in each support stay is engaged with the connection pin by the action of a spring to prevent the connection pin from coming off, so that each connection pin on the airframe side is connected to each support stay on the mower side. . Thereafter, the connecting operation is completed by connecting the front link and the front support stay. In the connection structure according to Patent Document 1, the front link must be connected manually after the rear link is connected.

  Patent Document 2 has a structure in which a hitch pin provided on the front link side and a hitch pin provided on the rear link side are automatically and simultaneously connected to front and rear hitch brackets (support stays) provided on a mower deck (blade housing). It is disclosed. However, in this structure, the hitch bracket is only formed with a long hole that opens in the longitudinal direction of the fuselage, and this connecting operation requires a highly accurate positioning between the mower deck and the fuselage. In addition, since the automatic linkage structure with the mower deck is incorporated in the lifting link mechanism, the structural design of the lifting link mechanism is restricted. For this reason, this automatic connection structure cannot be implemented using the conventional lifting link mechanism as it is.

  Patent Document 3 and Patent Document 4 also disclose an automatic connection structure between a lifting link mechanism and a mower deck (blade housing) including automatic connection of power transmission paths. However, here again, the automatic link structure with the mower deck is integrally incorporated in the lift link mechanism, which makes the lift link mechanism itself special. When adopting this automatic connection structure, it is difficult to divert the conventional lifting link mechanism.

Japanese Utility Model Laid-Open No. 4-110428 (FIGS. 1 and 3) Japanese Patent Laid-Open No. 10-339169 (FIGS. 3 and 4) US Pat. No. 7,877,972 (FIGS. 2 and 4) US Pat. No. 8,234,847 (FIGS. 2 and 4)

  In view of the above circumstances, there is a need for a mid-mount mower that enables the mower unit to be connected to the airframe without structurally restricting the conventional lifting link mechanism.

  A mid-mount mower equipped with a mower unit between a front wheel and a rear wheel below a fuselage according to the present invention includes a front link and a rear link provided on the fuselage with an interval in the front-rear direction of the fuselage. An elevating link mechanism, an intermediate structure that connects one end of the front link and one end of the rear link via a swing axis, and an engaged state that can be engaged with an engaging portion of the intermediate structure A blade housing provided with a portion, and the engagement portion and the engaged portion so that the blade housing placed on the ground and the intermediate structure are connected to each other as the machine body moves in the front-rear direction. And a guide surface that leads to the engagement position.

  In this configuration, in order to automatically connect the blade housing to the lifting link mechanism, an intermediate structure that relays the connection between the lifting link mechanism and the blade housing is provided. This intermediate structure is only swingably connected to one end of the front link and one end of the rear link constituting the lift link mechanism with respect to the lift link mechanism. The engaging portion and the engaged portion that function for this purpose are provided in the intermediate structure and the blade housing. Therefore, the conventional elevating link mechanism can be used as it is. In addition, since the alignment between the engaging portion and the engaged portion that must be achieved at the time of connection is guided by the guide surface, a certain amount of positional deviation is allowed in the movement of the aircraft in the front-rear direction, which is a burden on the aircraft operator. Is reduced.

  In order to manufacture the intermediate structure lightly and firmly, it is advantageous to configure the plate material and the bar material in a frame shape. For this reason, in one of the preferred embodiments of the present invention, the intermediate structure includes a first member and a second member extending in the longitudinal direction of the machine body with a space therebetween, and the first member and the second member. A front connecting member that connects the front portions of the first member and the rear connecting member that connects the rear portions of the first member and the second member, and the engaging portion includes both end portions of the first member and the first member. It is formed at both ends of the second member. In this configuration, a frame is created by the first member, the second member, the front connecting member, and the rear connecting member, and the engaged portion provided in the blade housing at a position spaced in the front-rear direction of the frame. Since the engaging part which engages with is arrange | positioned, the stable connection is implement | achieved between an intermediate structure and a blade housing.

  As a simple configuration for smoothly performing automatic connection between the intermediate structure and the blade housing as the machine body moves in the front-rear direction, a hole-pin engagement type is preferable. Therefore, in one of the preferred embodiments of the present invention, the engaging portion and the engaged portion are engaged with the long hole and the long hole that extend in the longitudinal direction of the body and open in the rear direction of the body. It is formed by a hole-pin engagement type consisting of an engagement pin.

  The simple structure of the guide surface that guides the engaging portion and the engaged portion to the engaging position with the movement of the airframe in the front-rear direction is the surface of the members that create the engaging portion and the engaged portion facing each other. It is to be a guide surface. In particular, in order to perform automatic automatic alignment with movement, it is preferable to use an inclined surface that contacts each other as a guide surface.

  When transmitting rotational power from the engine mounted on the airframe to the blade rotatably supported by the blade housing, a structure in which the power transmission mechanism is separated in the middle is employed. At this time, a power transmission mechanism for supplying engine power to the blades provided in the blade housing is divided into a body-side power transmission mechanism and a mower-side power transmission mechanism, and an output shaft of the body-side power transmission mechanism and the mower An embodiment in which a power coupling mechanism that couples the input shaft of the side power transmission mechanism is supported by the intermediate structure is advantageous. In this configuration, since the intermediate structure and the blade housing and the power system can be connected in the region of the intermediate structure, there is an advantage for the automatic connection in the present invention.

  In a preferred embodiment for constructing such a power coupling mechanism on the intermediate coupling body, the power coupling mechanism includes a first coupling end coupled to the output shaft and a first coupling end detachably coupled to the input shaft. A coupling body having two coupling ends, a coupling holding part for holding the coupling body, and an attachment unit for attaching the coupling holding part to the intermediate structure so as to be displaceable in the longitudinal direction of the machine body. In that case, the said attachment unit is comprised so that the said coupling holding | maintenance part may move straightly between the connection position in which connection is implement | achieved, and the release position in which connection release is implement | achieved. The first connection end and the output shaft can be connected in advance, but the second connection end and the input shaft must be connected or disconnected when the blade housing is connected or disconnected. In this embodiment, since the intermediate connection body that has been connected to the blade housing has a precise positional relationship with the blade housing, the second connection end and the input shaft are connected after the connection is completed. If it does in this way, the connection with a reliable 2nd connection end part and an input shaft will be implement | achieved only by linearly moving a coupling holding part.

  In order to reliably maintain the connection between the intermediate connecting body and the blade housing, it is necessary to lock the engaging connection between the engaging portion and the engaged portion. Further, in order to reliably maintain the power coupling mechanism of the power transmission mechanism in the coupled state, it is necessary to lock the coupling holding portion at the coupling position. Here, the lock mechanism that locks the coupling holding portion in the coupling position is referred to as a first lock mechanism, and the lock mechanism that locks the engagement portion and the engaged portion in the engagement position is the second. It is called a lock mechanism. In one preferred embodiment, the first lock mechanism and the second lock mechanism are integrally formed. In such an integrated lock mechanism, the first lock mechanism and the second lock mechanism have a common rotation operation shaft, and the first action portion provided on the rotation operation shaft rotates. Due to the displacement, the first locking mechanism locks the coupling holding portion at the coupling position, and the second locking mechanism is moved from the engaging portion by the rotational displacement of the second action portion provided on the rotational operation shaft. The engaged portion is locked at the engagement position. In this configuration, the first action portion acts on the coupling holding portion so as to prevent the coupling holding portion from being detached from the coupling position due to the rotation displacement of the common rotation operation shaft. The second action part acts on the engagement part so as to prevent the engagement part from being disengaged from the engagement position with the engaged part due to the rotation displacement of the common rotation operation shaft. Thus, the lock device is simplified by obtaining the rotation displacement that brings about locking or unlocking in the first lock device and the second lock device from the common rotation operation shaft. Furthermore, as a preferred embodiment, if the rotation operation with respect to the common rotation operation shaft is performed by the operation arm extending to the periphery of the driver seat, the locking operation of the two locking devices can be performed easily and Can be done simultaneously.

  In the normal blade housing, the lower end of the blade housing is floated by a gauge ring, so when connecting the intermediate connection body and the blade housing by forward movement of the aircraft over the blade housing placed on the ground, The blade housing may move during connection. When the blade housing moves, the connecting position is not secured and the connection becomes impossible. In order to prevent this, in one preferred embodiment of the present invention, the blade housing is provided with a gauge ring unit for changing the height of the blade housing with respect to the ground. The position can be switched to a setting position that creates a different ground height, and the setting position includes a position where at least a part of the blade housing is in contact with the ground. Accordingly, when the position of the gauge wheel unit is adjusted in advance so that at least a part of the blade housing is in contact with the ground during the connection operation, the movement of the blade housing can be prevented.

It is a schematic diagram explaining the basic structure of the mid-mount type mower according to the present invention, (a) shows the state immediately before connecting the intermediate structure mower unit 4 to the fuselage, (b) is the mower unit to the fuselage. Indicates a connected state. 1 is a side view of a mid-mount mower that is one specific embodiment of the present invention. FIG. It is a perspective view which shows a mower unit. It is a top view which shows a raising / lowering link mechanism and an intermediate structure. It is a perspective view which shows a raising / lowering link mechanism and an intermediate structure. It is a disassembled perspective view which shows a raising / lowering link mechanism and an intermediate structure separately. It is sectional drawing which shows the raising mechanism of a gauge ring, (a) shows the state in which the rear gauge ring is in contact with the ground, and (b) shows the state in which the rear gauge ring was flipped up. It is a top view which shows a mower unit. It is a top view which shows the mower unit and intermediate structure before the connection of a power connection mechanism. It is a top view which shows the mower unit and intermediate structure after the connection of a power connection mechanism. It is a vertical sectional view showing the action part on the right side of the first lock mechanism. It is the side view which showed the 1st locking mechanism before connection, and the blade housing was shown by the section. It is the side view which showed the 1st locking mechanism after a connection, and the blade housing was shown by the cross section. It is a side view which shows the mower unit raised by the raising / lowering link mechanism. It is a perspective view which shows a 1st locking mechanism and a 2nd locking mechanism. It is a perspective view which shows the state in which a part of connection location of an intermediate structure and a blade housing is locked by the 1st locking mechanism and the 2nd locking mechanism.

Before describing a specific embodiment of the mid-mount mower according to the present invention, a basic configuration characterizing the present invention will be described with reference to FIG.
The mid-mount mower shown in FIG. 1 (hereinafter simply referred to as “mower”) includes a mower unit 4 between a front wheel 2a and a rear wheel 2b below a machine body 1 having a machine frame 10 as a core element. Can be equipped. In the lower part of the machine body 1, an elevating link mechanism 3 including a pair of left and right front links 31 and a rear link 32 is provided. The intermediate structure 6 is suspended by the free end of the front link 31 and the free end of the rear link. The free end of the front link 31 and the free end of the rear link 32 are connected to the intermediate structure 6 through a swing axis, and the intermediate structure 6 is displaced up and down with respect to the ground by the swing of the lift link mechanism 3. To do. That is, the upper structure 9 for mounting the mower unit 4 on the airframe 1 is constructed by the lifting link mechanism 3 and the intermediate structure 6. Here, the upper structure 9 is detachably connected to the blade housing 40 which is the core member of the mower unit 4. That is, in one embodiment, the upper structure 9 functions as an adapter that connects the airframe 1 and the mower unit so as to be movable up and down. In another embodiment, the intermediate structure 6 functions as an adapter for connecting the elevating link mechanism 3 and the mower unit 4. Therefore, the intermediate structure 6 is provided with an engaging portion 610, and the blade housing 40 of the mower unit 4 is provided with an engaged portion 620 that can be connected to the engaging portion 610.

  FIG. 1A shows a state immediately before the connection between the intermediate structure 6 and the mower unit 4, and FIG. 1B shows a state immediately after the connection. The locus of the front wheel 2a at the time of connection is indicated by a dotted line in FIG. As can be understood from FIGS. 1A and 1B, the mower moves over the mower unit 4 placed horizontally on the ground, so that the engaged portion 620 of the blade housing 40 has an intermediate structure. When the engaging part 610 of the body 6 is engaged, the mower unit 4 and the intermediate structure 6 are connected, and as a result, the mower unit 4 and the machine body 1 of the mower are realized. In order to facilitate the engagement between the engaging portion 610 of the intermediate structure 6 and the engaged portion 620 of the blade housing 40 accompanying the movement of the airframe 1 in the front-rear direction, the airframe 1 is moved in the front-rear direction. A guide surface 630 that guides the engaging portion 610 to an engaging position where the engaging portion 610 engages with the engaged portion 620 is formed on the intermediate structure 6 and / or the mower unit 4.

  Various types of engagement between the engaging portion 610 and the engaged portion 620 can be adopted. However, as a simple structure, a long hole extending in the machine body moving direction and the long hole are engaged. A hole (slit) -pin engagement type consisting of an engagement pin is suitable. Alternatively, a concave-spherical form composed of a curved concave portion that opens in the machine movement direction and a spherical body that enters the curved concave portion is also suitable. As the simple structure of the guide surface 630, an inclined surface that is inclined with respect to the moving direction of the airframe and is guided to an appropriate position as the airframe 1 travels is suitable. If it is provided at 620 or both, the structure is simplified and convenient.

  In general, since the mower unit 4 does not include a power source, in order to rotate the blade 43 provided in the blade housing 40, the power from the engine 23 mounted on the mower is used as the work power transmission mechanism 25. Receive through. The work power transmission mechanism 25 is divided into a body-side power transmission mechanism 25A and a mower-side power transmission mechanism 25B. The engine power is transmitted to the blade 43 by connecting the free shaft end (hereinafter also referred to as output shaft) of the machine body side power transmission mechanism 25A and the free shaft end (hereinafter also referred to as input shaft) of the mower side power transmission mechanism 25B. The The output shaft of the machine body side power transmission mechanism 25 </ b> A and the input shaft of the mower side power transmission mechanism 25 </ b> B are connected by the power connection mechanism 7. The power coupling mechanism 7 is preferably supported by the intermediate structure 6, but may be supported by the mower unit 4. The power connection mechanism 7 includes a coupling body 70 having a first connection end connected to the output shaft and a second connection end detachably connected to the input shaft. The coupling body 70 is relatively displaced, preferably linearly moved, between a release position where the connection between the airframe side power transmission mechanism 25A and the mower side power transmission mechanism 25B is released and a connection position where the connection is realized.

  A lock that mechanically holds the connecting position of the engaging portion 610 and the engaged portion 620 and the connecting position of the coupling body 70 that realize the connection between the elevating link mechanism 3 and the mower unit 4 via the intermediate structure 6. A mechanism is provided but not shown in FIG. Such a locking mechanism can be constructed by a spring biasing mechanism or a locking mechanism. The operation of the locking mechanism is conveniently performed by an operating body extending to the periphery of the driver seat 21. In particular, the connecting position of the engaging portion 610 and the engaged portion 620 and the connecting position of the coupling body 70 are preferably locked by a common locking mechanism, but may be constructed separately.

  The blade housing 40 is provided with a front gauge wheel unit 45 at the front edge of the fuselage and a rear gauge wheel unit 46 at the rear edge of the fuselage in order to change the height of the blade housing to the ground. At least one gauge wheel included in the gauge wheel unit 46 including the front gauge wheel unit 45 and the rear gauge wheel unit 46 can be changed to a position where at least a part of the blade housing 40 comes into contact with the ground. By bringing at least a part of the blade housing 40 into contact with the ground, the mower unit 4 is restrained from moving in the connecting operation of the mower unit 4 including traveling over the mower unit 4 with the mower.

  In the description using FIG. 1 and FIG. 2, the intermediate structure 6 and the lifting link mechanism 3 have been described in the embodiments that are separate components. The upper structure 9 integrated with the link mechanism 3 can also be used in an embodiment in which the upper structure 9 functions as an attachment adapter for the mower unit 4. If the function of the intermediate structure 6 as an attachment adapter for the mower unit 4 and the function of the lifting link mechanism 3 for lifting and lowering the mower unit 4 are realized, the configurations of the intermediate structure 6 and the lifting link mechanism 3 are free. is there. In the present invention, the intermediate structure 6 and the elevating link mechanism 3 are not limited to being a single component.

Next, one specific embodiment of a mower according to the present invention will be described with reference to the drawings. FIG. 2 is a side view of the mower. Although this mower is equipped with the mower unit 4 between the front wheel 2a and the rear wheel 2b, it can be used as a general tractor by removing the mower unit 4.
The mower includes a water-cooled diesel engine (hereinafter referred to as an engine) 23 covered with a bonnet 11 in the front half of the body frame 10, and a driver seat 21 in the latter half of the body frame 10. The front wheel 2a is a steered wheel operated by the steering wheel 22, and at the same time is a drive wheel. This four-wheel drive is used, and the rear wheel 2b is also a drive wheel. A transmission case (hereinafter referred to as a T / M case) 13 is provided in the rear half of the body frame 10.

  The power from the engine 23 is a hydrostatic continuously variable transmission (hereinafter referred to as HST) 15 connected to the front portion of the T / M case 13 via a transmission shaft (not shown) constituting the power transmission mechanism 24. The output of the HST 15 is transmitted to a gear transmission (not shown) provided in the T / M case 13. The power from the gear transmission is distributed to the front wheel driving power and the rear wheel driving power inside the T / M case 13. The power for driving the front wheels is transmitted to the left and right front wheels 2a via the front wheel power transmission mechanism (which constitutes the power transmission mechanism 24) from the T / M case 13 to the left and right front wheels 2a. The power for driving the rear wheels is transmitted to the left and right rear wheels 2b via the rear wheel power transmission mechanism (which constitutes the power transmission mechanism 24) from the T / M case 13 to the left and right rear wheels 2b.

  On the other hand, the motive power input to the HST 15 includes a rearward first power take-off shaft 16 provided at the rear end of the T / M case 13 and a forward second power take-out shaft 17 provided at the bottom of the T / M case 13. Is transmitted to. The first power extraction shaft 16 and the second power extraction shaft 17 constitute a work power transmission mechanism 25, and the second power extraction shaft 17 supplies power to the mower unit 4.

  At the rear part of the T / M case 13, 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 the lift arms 18 are interlocked with the up and down swings. And a link mechanism 19 that swings up and down in the vertical direction. A single acting hydraulic cylinder is adopted as the lift cylinder. The link mechanism 19 includes a pair of left and right lower links 19a that enable attachment / detachment of a working device (not shown) such as a rotary tiller or a plow.

  This mower has the basic configuration of the present invention described with reference to FIG. A mower unit 4 is provided below the body frame 10 between the front wheels 2a and the rear wheels 2b. Between the body frame 10 and the mower unit 4, the elevating link mechanism 3 and the intermediate structure 6 are interposed. The lift link mechanism 3 suspends and supports the mower unit 4 via the intermediate structure 6 so as to be lifted and lowered. The intermediate structure 6 functions as an adapter, and is connected to the lifting link mechanism 3 on the one hand and to the mower unit 4 on the other hand.

  The elevating link mechanism 3 includes a pair of left and right front links (oscillating links) 31 that connect the front part of the body frame 10 and the front part of the intermediate structure 6 in a rearward downward tilting posture, and the airframe frame 10 in a rearward downward tilting posture. A pair of left and right rear links (oscillating links) 32 that connect the front and rear intermediate portions of the intermediate structure 6 and the rear portion of the intermediate structure 6, and a parallel link that moves the mower unit 4 up and down in a predetermined trimming posture via the intermediate structure 6. It is composed. The left and right rear links 32 are linked to the left and right lower links 19 a of the link mechanism 19 via the linkage mechanism 34.

  The linkage mechanism 34 is a pair of left and right rotating shafts 341 that are mounted on the body frame 10 so as to be rotatable, and a pair of left and right mounted integrally on the rotating shaft 341 in a state of extending from the rotating shaft 341 toward the front of the vehicle body. One linkage arm 342, a pair of left and right second linkage arms 343 integrally provided on the rotation shaft 341 in a state of extending from the rotation shaft 341 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 13 The interlocking arms 344, the pair of left and right first linkage rods 345 that link the left and right first linkage arms 342 to the free end side of the corresponding rear link 32, and the left and right second linkage arms 343 are linked to the corresponding linkage arms 344. And a pair of left and right second linkage rods 346. The left and right interlocking arms 344 are externally fitted on the support shaft 347 of the corresponding lower link 19a so as to be able to swing relative to each other. The upper part of the left and right interlocking arms 344 abuts against the upper edge of the lower link 19a of the link mechanism 19 from above as a stopper for restricting the swinging of the interlocking arm 344 due to the load applied to the left and right rear links 32. One part is bent.

  That is, the mower unit 4 is connected to the machine body frame 10 via the lifting link mechanism 3 and the intermediate structure 6, and the lifting link mechanism 3 is linked to the link mechanism 19 via the linkage mechanism 34, thereby The unit 4 can be moved up and down at the lower abdomen of the tractor.

  Although not shown in detail in FIG. 2, the rotating shaft 341 is integrally provided with a single third linkage arm 348 extending toward the rear of the vehicle body. The machine body frame 10 has a lower limit setting mechanism 35 that receives the third linkage arm 348 that swings up and down in conjunction with the downward swing of the left and right rear links 32, thereby preventing the left and right rear links 32 from swinging downward. Equipped. The lower limit setting mechanism 35 includes an operating body 36 that can be rotated around the vertical axis from the boarding operation unit, an operating body 36 and a cylindrical receiving portion 37 that rotates integrally around the vertical axis. Has been. And the lower edge of the receiving part 37 which receives the 3rd linkage arm 348 is formed in the step shape from which height differs in the circumferential direction.

  With this configuration, by rotating the operating body 36 about the longitudinal axis from the boarding operation unit, the receiving height position of the third linkage arm 348 by the receiving unit 37 can be changed to an arbitrary height position. The lower limit position of the left and right rear links 32 relative to the body frame 10 (hereinafter referred to as the lower limit position of the rear links 32) can be easily changed.

  That is, the lower limit setting mechanism 35 can change the setting of the lower limit position of the left and right rear links 32. As a result, the lower limit height of the mower unit 4 with respect to the machine frame 10 is changed.

  FIG. 2 shows the lifting / lowering link mechanism 3, the intermediate structure 6, and the mower unit 4. Here, the intermediate structure 6 and the mower unit 4 are connected to each other. In FIG. 3, only the mower unit 4 is shown. 4, 5, and 6 show the intermediate structure 6 connected to the lift link mechanism 3. In FIG. 6, the front link 31, the rear link 32, and the intermediate structure 6 are separated. It is shown. As is clear from FIG. 3, the mower unit 4 is not confirmed in FIG. 3, but the vertical rotation shaft 43a for rotating the three blades arranged in the transverse direction of the aircraft in a plan view in the clockwise direction and these blades. A blade housing 40 that covers from above is provided. The blade housing 40 includes a top plate 41 and a side plate 42 extending downward from the periphery of the top plate 41. The top plate 41 of the blade housing 40 is provided with a power distribution mechanism 44 for driving the blade. Also, a transmission cover that covers the belt transmission mechanism 44c of the power distribution mechanism 44 from above is detachably attached, but is omitted in FIG. The blade housing 40 forms an upwardly extending bulging portion on the left and right sides in the front region thereof, thereby creating a conveyance path for cutting grass therein. A discharge cover 40a is attached to the right end of the blade housing 40 that serves as a discharge port of the conveyance path.

  That is, the mower unit 4 moves the grass cut by the three blades from the discharge port at the right end to the outside through the conveyance path formed inside the blade housing 40 by the conveyance air generated as each blade rotates. It is configured to discharge side discharge.

  As shown in FIG. 3, a front gauge wheel unit 45 whose height can be adjusted and a rear gauge wheel unit 46 whose height can be adjusted are provided at the left and right ends of the front and rear parts of the blade housing 40, respectively. In FIG. 7, only the rear gauge wheel unit 46 is shown enlarged. The front gauge wheel unit 45 includes a support bracket 45b having a vertical boss portion 45c, and a front gauge wheel 45a provided on an axle fixed to a sliding support shaft 45d that is slidably inserted into the vertical boss portion 45c. It has. The sliding support shaft 45d is fixed at a selected position by pin fixing. As shown in detail in FIG. 7, the rear gauge wheel unit 46 is slidable on the support bracket 46 b provided with a vertical boss portion 46 c that is flipped upward by a flip-up mechanism 47, and the vertical boss portion 46 c. And a rear gauge wheel 46a provided on an axle fixed to the sliding support shaft 46d to be inserted. The sliding support shaft 46d is also fixed at a selected position by pin fixing. In this embodiment, the flip-up mechanism 47 slides by locking the vertical boss portion 46c supported so as to be swingable around the horizontal axis with respect to the support bracket 46b by a spring-biased swing arm. While maintaining the vertical posture of the moving support shaft 45d (see FIG. 7A), the sliding support shaft 45d is brought into an inclined posture by releasing the locking arm (see FIG. 7B). ) Configuration. That is, the flip-up mechanism 47 has a function of jumping up the rear gauge wheel 46a upward by releasing the spring bias. When the rear gauge wheel 46a is flipped upward, the lower end of the side plate 42 of the blade housing 40 comes into contact with the ground. As a result, a large frictional force acts between the blade housing 40 and the ground, so that the movement of the blade housing 40 is suppressed even when a force is applied from the outside.

  Although clearly illustrated in FIG. 8, the power distribution mechanism 44 includes an input shaft 44 (a component of the mower-side power transmission mechanism 25 </ b> B) that extends rearward from a housing 44 a disposed in the center of the blade housing 40, an input shaft. A belt transmission mechanism 44c is provided that distributes the power received by 44b to the three rotary shafts 43a to which the blades 43 are fixed.

  Next, an embodiment of the intermediate structure 6 will be described with reference to FIGS. 4, 5, 6, 9 and 10. The intermediate structure 6 includes a first member 61 and a second member 62 that extend in the longitudinal direction of the machine body with a space therebetween, and a front connecting member 63 that connects the front portions of the first member 61 and the second member 62. And the frame structure comprised from the back connection member 64 which connects the rear parts of the 1st member 61 and the 2nd member 62 is provided. The front connecting member 63 is a rod body having a central portion protruding in a convex shape, and a hook-like free end portion of the front link 31 of the elevating link mechanism 3 is swingably locked to the protruding portion. . A free end portion of the rear link 32 of the lifting link mechanism 3 is pin-coupled to the rear portions of the first member 61 and the second member 62 through a link pin 39 so as to be swingable.

  In order to connect the intermediate structure 6 and the blade housing 40, an engagement portion 610 is provided in the intermediate structure 6, and the top plate 41 of the blade housing 40 can be engaged with the engagement portion 610. An engaged portion 620 is provided. In this embodiment, the engaging portion 610 includes a body-side first front guide 611 that is a bent portion formed in a joining region of the first member 61 with the front connecting member 63, and the front connecting member 63 of the second member 62. A fuselage-side second front guide 612 that is a bent portion formed in a joining area between the fuselage, and a fuselage-side first rear guide 613 that is a bracket-like member protruding outward from the rear end portion of the first member 61. The airframe side second rear guide 614 is a bracket-like member that protrudes outward from the rear end portion of the first member 61.

  The engaged portion 620 is divided in the left-right direction in the mower-side first front guide 621 and the mower-side second front guide 622, which are erected in the front-side region of the top plate 41, and the rear-side region in the top-plate 41. The mower-side first rear guide 623 and the mower-side second rear guide 624 are provided. Mower side first front guide 621 and body side first front guide 611, mower side second front guide 622 and body side second front guide 612, mower side first rear guide 623 and body side first rear guide 613, mower side The second rear guide 624 and the airframe side second rear guide 614 are disposed at positions where they are engaged with each other in the connected state of the intermediate structure 6 and the blade housing 40.

  In this embodiment, the airframe side first front guide 611 and the airframe side second front guide 612 are each provided with an engagement pin 69A extending horizontally in the diagonally forward direction, and the airframe side first rear guide. 613 and the airframe side second rear guide 614 are provided with a long hole 69C that extends horizontally in an oblique direction and opens to the front side. Furthermore, each of the mower-side first front guide 621 and the mower-side second front guide 622 is provided with a long hole 69B that extends horizontally in the oblique rearward direction and opens to the rear side.

  Further, in the rear region of the top plate 41, a rotation operation shaft 80 of the lock mechanism 8, which will be described in detail later, extends in the vehicle body transverse direction (lateral direction). The side first rear guide 613 and the machine body side second rear guide 614 function as engaging pins into which the elongated holes 69C are engaged.

  Airframe side first front guide 611, Airframe side second front guide 612, Airframe side first rear guide 613, Airframe side second rear guide 614, Mower side first front guide 621, Mower side second front guide 622, Mower The side first rear guide 623 and the mower side second rear guide 624 each have an inclined surface that approaches the longitudinal axis of the machine body as it goes forward, and the corresponding inclined surfaces are the intermediate structure 6 and the blade housing 40. In the connected state, they are formed so as to substantially contact each other. That is, these inclined surfaces function as guide surfaces that guide the intermediate structure 6 to a connection position with the blade housing 40 when the mower advances with respect to the blade housing 40 placed on the ground. That is, a guide surface as an inclined surface is formed on each of the engaging portion 610 of the intermediate structure 6 and the engaged portion 620 of the blade housing 40, and these guide surfaces mutually move along with the longitudinal movement of the machine body. Contact.

  The second power take-off shaft 17 transmits power to the input shaft 44b (see FIG. 6) of the power distribution mechanism 44 of the mower unit 4, and the working power transmission mechanism 25 in the meantime is composed of the machine-side power transmission mechanism 25A and the mower. It is divided into a side power transmission mechanism 25 </ b> B, and both can be connected and separated by a power connection mechanism 7 provided in the intermediate structure 6. In this embodiment, the input shaft 44b is included in the first universal joint 25b and the mower side power transmission mechanism 25B. The fuselage side power transmission mechanism 25A includes the relay shaft 25a, the first universal joint 25b, A second universal joint 25c is included. The first universal joint 25b connects the second power take-out shaft 17 and the relay shaft 25a. The second universal joint 25c connects the relay shaft 25a that functions as the output shaft of the machine body side power transmission mechanism 25A and the input shaft 44b that functions as the input shaft of the mower side power transmission mechanism 25B. The second universal joint 25c is formed with a spline type connecting portion that enables connection to and disconnection from the input shaft 44b. A mechanism for performing this connection and disconnection is a power connection mechanism 7. The detached state of the power coupling mechanism 7 is shown in FIG. 9, and the coupled state is shown in FIG.

  As can be understood from FIGS. 9 and 10, the power coupling mechanism 7 includes a coupling main body 70 that is the second universal joint 25 c in this embodiment, and an outer peripheral surface surrounding the coupling main body 70. A coupling holding portion 73 that holds the coupling main body 70 and an attachment unit 75 that attaches the coupling holding portion 73 to the intermediate structure so as to be displaceable in the longitudinal direction of the machine body. The coupling body 70 includes a first connection end 71 connected to the relay shaft 25a and a second connection end 72 connected to the input shaft 44b. The second connection end 72 is formed on the input shaft 44b. And an inner peripheral surface formed with a spline that engages with the spline. The coupling holding portion 73 is a boss body having protrusions on both sides, and the coupling body 70 is fixed to the boss hole of the boss body, and is moved toward the input shaft 44b of the power distribution mechanism 44. The input shaft 44b and the second connecting end 72 have a function of spline engagement. The mounting unit 75 realizes such movement of the coupling holding portion 73. For this reason, the attachment unit 75 is configured as a slider mechanism for moving the coupling holding portion 73. By applying a force (for example, an operating force by the driver) to the slider mechanism from the outside, the coupling holding portion 73 moves and the connection of the power connecting mechanism 7 is realized. In this embodiment, in order to translate the coupling holding portion 73, a first leg 75a and a second leg 75b as a pair of left and right slider rods and a guide hole as a slide guide for each slider rod are provided. ing. The first leg portion 75a is a rod-like member that is fixed to the left end portion of the coupling holding portion 73 and extends rearward, and the second leg portion 75b is fixed to the right end portion of the coupling holding portion 73 and rearward. It is the rod-shaped member extended in. The guide hole is a through hole formed in the first bracket 65a and the second bracket 65b provided in the first member 61 and the second member 62 as described below. The first leg portion 75a and the second leg portion 75b are slidably supported by the first bracket 65a and the second bracket 65b by being inserted into the through hole. In this embodiment, the attachment unit 75 is supported by the first member 61 and the second member 62, that is, supported by the intermediate structure 6. 1 may be supported.

  The intermediate structure 6 has an end fixed to the first member 61 and extends toward the second member 62. The intermediate structure 6 has a U-shaped first bracket 65 a in plan view and an end on the second member 62. A U-shaped second bracket 65b that is fixed and extends toward the first member 61 in a plan view is provided. A gap through which the relay shaft 25a can pass is formed between the tip of the first bracket 65a and the tip of the second bracket 65b. A hole through which the first leg 75a is inserted is provided in the distal end region of the first bracket 65a, and a hole through which the second leg portion 75b is inserted is provided in the distal end region of the second bracket 65b. The first leg portion 75a and the second leg portion 75b are supported by the attachment unit 75 so as to be movable in the longitudinal direction of the machine body. In a state where the intermediate structure 6 is connected to the blade housing 40, the coupling holding portion 73 is moved together with the attachment unit 75 toward the input shaft 44 b of the power distribution mechanism 44 to a predetermined connection position, thereby coupling body ( The second connecting end 72 of the second universal joint 25c) is splined to the input shaft 44b.

  As shown in FIGS. 9 and 10, there is a cup between the first leg 75a and the first bracket 65a and between the second leg 75b and the second bracket 65b of the power distribution mechanism 44. A spring 76 that biases the coupling main body 70 held by the ring holding portion 73 and the input shaft 44b of the power distribution mechanism 44 in a direction to release the connection is disposed. Therefore, when the lock mechanism 8 is rotated in the unlocking direction, the coupling body 70 automatically comes off the input shaft 44b. In FIG. 9, the spring 76 is shown in an expanded state, that is, a state before the input shaft 44b and the second connecting end 72 are spline-engaged, and in FIG. 10, the spring 76 is in a compressed state, that is, A state after the input shaft 44b and the second connecting end portion 72 are spline engaged is shown.

  Next, the lock mechanism 8 provided in the blade housing 40 in this embodiment will be described with reference to FIGS. As shown in a plan view in FIG. 8, in this embodiment, the lock mechanism 8 includes a first lock mechanism 8 </ b> A that locks the coupling holding portion 73 at the coupling position, an engagement portion 610, and an engaged portion. And a second lock mechanism 8B that locks 620 at the engagement position. The first lock mechanism 8A and the second lock mechanism 8B are provided with a common rotation operation shaft 80. The rotation operation shaft 80 moves the rear end region of the top plate 41 of the blade housing 40 in the transverse direction. It extends and is rotatably supported by a plurality of bearing stands. The rotation operation shaft 80 is provided with two first action portions 81 for the first lock mechanism 8A and two second action portions 82 for the second lock mechanism 8B. As the rotation operation shaft 80 rotates, the first action portion 81 contacts a contact portion provided at the rear end of the first leg portion 75a and the second leg portion 75b of the power coupling mechanism 7. However, it is an arm that presses the coupling holding portion 73 against the connecting position and holds the connecting position. The second action part 82 contacts the pin-like protrusion 61 a provided on the first member 61 and the pin-like protrusion 62 a provided on the second member 62 as the turning operation shaft 80 rotates. The hook-like arm holds the connection between the intermediate structure 6 and the blade housing 40 by holding the engaging portion 610 and the engaged portion 620 in the engaging position while being held. A rod-shaped operation arm 83 extending to the periphery of the driver seat 21 is fixed to one end of the rotation operation shaft 80, and the lock mechanism 8 is locked by the operation of the operation arm 83 by the driver sitting on the driver seat 21. And unlocking becomes possible.

  When the mower unit according to the present invention is equipped with the mower unit 4 in the airframe 1, the mower unit 4 travels over the mower unit 4 placed horizontally on the ground. For this reason, the blade housing 40 is provided with a climbing mechanism 5. As shown in FIGS. 3 and 11, the climbing mechanism 5 is prepared for each of the left and right front wheels 2a, and the interval thereof corresponds to the front wheel tread width. The climbing mechanism 5 extends above the belt transmission mechanism 44c disposed on the top plate 41 of the blade housing 40 in the front-rear direction, and extends obliquely from the front end of the bridge portion 50 toward the ground. It consists of a front auxiliary plate 51 and a rear auxiliary plate 52 extending obliquely from the rear end of the bridge portion 50 toward the ground. The bridge portion 50 is composed of a pair of arch-shaped rods having a flat middle portion and a footboard laid on the upper surface of the middle portion of the pair of rods. Further, side plates 53 are provided on both sides of the bridge portion 50. It is attached. The front auxiliary plate 51 and the rear auxiliary plate 52 are configured to be slidable so as to be housed in the bridge portion 50 when not in use. In this case, the slide-type storage is realized by the guide pin 51a provided at the rear end of the front auxiliary plate 51, the guide pin 52a provided at the front end of the rear auxiliary plate 52, and the guide slit 53a. . The guide slits 53a are formed substantially horizontally in the front-rear direction so that each of the guide pins 51a and the guide pins 52a is engaged and guided when moving, but the guide slits 53a are in front and are pulled out. In order to securely hold the inclined postures of the auxiliary plate 51 and the rear auxiliary plate 52, the end portions are formed as vertical slit portions.

  First, in order to equip the lower abdomen of the tractor with the mower unit 4, the lifting link mechanism 3 is operated to lower the intermediate structure 6 to the lower limit position. Subsequently, the body 1 is advanced so that the front wheel 2 a passes over the blade housing 40 through the upper part of the blade housing 40 by using the climbing mechanism 5 from behind the mower unit 4. When the front wheel 2a gets over the blade housing 40, the engaging portion 610 provided in the intermediate structure 6 is just in the engaged portion 620 (four front and rear, left and right guides 621 to 624) provided in the blade housing 40. (Four guides 611 to 614 on the front, rear, left and right) engage. That is, the engagement pins 69A provided on the machine body side first front guide 611 and the machine body side second front guide 612 are guided by the respective guide surfaces 630, and the mower side first front guide 621 and the mower side second front. It enters the long hole 69B provided in the guide 622. At that time, the machine-side first rear guide 613 and the machine-side second rear guide 614 are in surface contact with the mower-side first rear guide 623 and the mower-side second rear guide 624, respectively, and the mower-side first rear guide. 623 and the mower side second rear guide 624 enter the area restricted by the second side guide 624. At the same time, the rotation operation shaft 80 of the lock mechanism 8 as an engagement pin relatively enters the elongated hole 69 provided in the machine body side first rear guide 613 and the machine body side second rear guide 614. After the front wheel 2a gets over the blade housing 40, the airframe 1 is stopped.

  At this time, the shaft of the coupling body 70 of the power coupling mechanism 7 provided in the intermediate structure 6 on the axis of the input shaft 44b protruding rearward in the longitudinal direction of the power distribution mechanism 44 of the mower unit 4 The wick is located. The input shaft 44b and the coupling body 70 are arranged coaxially in the longitudinal direction of the body.

  After the airframe 1 is stopped, the driver operates the operation arm 83 of the lock mechanism 8 to rotate the rotation operation shaft 80 (see FIGS. 13 and 14). As a result, the arm constituting the first action part 81 of the lock mechanism 8 has the rear ends (the contact parts) of the first leg part 75a and the second leg part 75b of the power coupling mechanism 7 provided in the intermediate structure 6. ) And the coupling holding portion 73 is moved together with the coupling main body 70 to connect the input shaft 44b and the coupling main body 70 (see FIG. 16). At the same time, the two hook-like arms constituting the second action part 82 rotate and hold the pin-like protrusion 61 a provided on the first member 61 and the pin-like protrusion 62 a provided on the second member 62. Include. Thereby, the engaging part 610 and the to-be-engaged part 620 will be in a final engagement state. That is, in this embodiment, the airframe side first front guide 611 and the mower side first front guide 621, the airframe side second front guide 612 and the mower side second front guide 622, the airframe side first rear guide 613 and the mower side first guide. The first rear guide 623, the machine body side second rear guide 614, and the mower side second rear guide 624 are in their final engaged state. This engaged state is maintained as long as the two hook-like arms that are the second action portions 82 hold down the protrusions 61a and 62a, respectively. This engagement holding state is shown enlarged in FIG. Further, in order to maintain this engaged state, a lock device 84 that locks the rotation operation shaft 80 at the engagement rotation position is provided at a connection portion between the operation arm 83 and the rotation operation shaft 80. Since the structure of the lock device 84 is well known and not shown in detail, in this embodiment, the lock operation shaft 80 is locked by engaging the lock pin in the lock hole at the engagement rotation position. The lock operation shaft 80 is unlocked by removing the lock pin from the lock hole. Of course, other lock structures may be employed.

  When detaching the mower unit 4 from the airframe 1, the driver operates the operation arm 83 of the lock mechanism 8 after lowering the elevating link mechanism 3 so that the mower unit 4 contacts the ground. The rotation operation shaft 80 is rotated to the unlock position. As a result, the connection between the input shaft 44b and the coupling body 70 is released. Further, the body 1 is moved backward so that the front wheel 2 a passes over the blade housing 40 through the upper portion of the blade housing 40 by using the climbing mechanism 5 from the front of the mower unit 4. Through this backward movement, the engaging portion 610 (four front / rear and left / right guides 611 to 614) provided in the intermediate structure 6 is engaged with the engaged portion 620 (four front / rear and left / right guides 621) provided in the blade housing 40. Exit from ~ 624). When the front wheel 2a gets over the blade housing 40, the mower unit becomes free and can be carried out freely.

[Another embodiment]
[1] The engagement structure of the engaging portion 610 provided in the intermediate structure 6 and the engaged portion 620 provided in the blade housing 40 for connecting the intermediate structure 6 and the blade housing 40 is an airframe. Any engagement type other than the hole-pin engagement type, for example, a claw engagement type, as long as it can be engaged by approaching in the front-rear direction of the machine and disengaged by separation in the front-rear direction of the machine Etc. may be adopted, or these may be mixed. The engagement connection points created by the engagement portion 610 and the engaged portion 620 are four positions in the front, rear, left and right in the above embodiment, but may be two or more.

[2] In the above-described embodiment, the plate surfaces of the airframe side first front guide 611 and the mower side first front guide 621 that are in contact with each other are used as the guide surface 630, and the airframe side second front guide 612 and the mower side first guide The plate surfaces of the two front guides 622 that are in contact with each other are used as the guide surfaces 630, but instead of this, members that create the guide surfaces 630 may be provided separately. Further, the rotation operation shaft 80 of the lock mechanism 8 is used as an engagement pin that engages with the long hole 69C provided in the machine body side first rear guide 613 and the machine body side second rear guide 614. An engagement pin may be provided on the blade housing 40.

[3] The mower unit 4 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 blade housing 40. The grass cut by the blade may be configured to have a mulching specification in which the grass is chopped by flowing inside the blade housing 40 and then dropped onto the ground below from the opening at the bottom of the blade housing 40. Further, the number of blades provided in the mid-mount mower unit 4 and the transmission structure for the blades can be variously changed.

  The present invention can be applied to a mower equipped with various mower units 4 configured to be able to get over the left and right front wheels detachably between the front wheels and the rear wheels, and the structure of the lifting link mechanism and mower unit 4. There is no limit.

1: Airframe 10: Airframe frame 21: Driver's seat 25: Power transmission mechanism for work 25A: Airframe side mechanism 25B: Mower side mechanism 25a: Relay shaft 25b: First universal joint 25c: Second universal joint 3: Lifting link mechanism 31 : Front link 32: Rear link 4: More unit 40: Blade housing 41: Top plate 42: Side plate 44: Power distribution mechanism 44b: Input shaft 44c: Belt transmission mechanism 45: Front gauge wheel unit 46: Rear gauge wheel unit 47: Bounce mechanism 5: Overpass mechanism 6: Intermediate structure 610: Engagement part 611: Airframe side first front guide 612: Airframe side second front guide 613: Airframe side first rear guide 614: Airframe side second rear guide 620 : Engaged portion 621: mower side first front guide 622: mower side second front guide 623: mower side first rear guide 624: Moer side second rear guide 630: Guide surface 61: First member 61a: Projection 62: Second member 62b: Projection 65: Intermediate member 69A: Engagement pin 69B: Long hole 69C: Long hole 7: Power connection Mechanism 70: Coupling body 71: First connecting end 72: Second connecting end 73: Coupling holding portion 75: Mounting unit 75a: Leg portion 8: Lock mechanism 8A: First lock mechanism 8B: Second lock mechanism 80: Rotating operation shaft 81: First action part 82: Second action part 83: Operation arm 9: Upper structure (elevating link mechanism + intermediate structure)

Claims (13)

A mid-mount mower with a mower unit between the front and rear wheels below the fuselage,
An elevating link mechanism including a front link and a rear link provided in the airframe with a space in the longitudinal direction of the airframe;
An intermediate structure that connects one end of the front link and one end of the rear link via a swing axis;
A blade housing provided with an engaged portion engageable with the engaging portion of the intermediate structure;
A guide surface that guides the engaging portion and the engaged portion to an engaging position so that the blade housing placed on the ground and the intermediate structure are connected to each other as the machine body moves in the front-rear direction; ,
Mid-mount mower with   The intermediate structure includes a first member and a second member that extend in the longitudinal direction of the machine body with a space therebetween, and a front connection member that connects front portions of the first member and the second member to each other. 2. A rear connection member that connects the rear portions of the member and the second member, and the engagement portions are formed at both ends of the first member and both ends of the second member. The described mid-mount mower.   The engaging portion and the engaged portion are formed in a hole-pin engagement type that includes a long hole that extends in the longitudinal direction of the body and opens in the rear direction of the body and an engagement pin that engages with the long hole. The mid-mount mower according to claim 2.   The mid-mount mower according to claim 2 or 3, wherein the guide surface is an inclined surface formed in the engaging portion and the engaged portion.   5. The mid-mount mower according to claim 4, wherein the guide surface of the engaging portion and the guide surface of the engaged portion are in contact with each other as the aircraft moves in the longitudinal direction.   A power transmission mechanism that supplies engine power to the blades provided in the blade housing is divided into a body side power transmission mechanism and a mower side power transmission mechanism, and an output shaft of the body side power transmission mechanism and the mower side power transmission The mid-mount mower according to any one of claims 1 to 5, wherein a power coupling mechanism that couples an input shaft of the mechanism is supported by the intermediate structure.   The power connection mechanism includes a coupling body having a first connection end connected to the output shaft and a second connection end connected to the input shaft in a detachable manner, and a coupling holding portion for holding the coupling body And a mounting unit for attaching the coupling holding portion to the intermediate structure so as to be displaceable in the longitudinal direction of the machine body.   The attachment unit includes a coupling position at which the coupling holding portion is coupled to the input shaft of the second coupling end, and a release position at which the coupling release of the second coupling end from the input shaft is achieved. The mid-mount mower according to claim 7, wherein the mid-mount mower is moved linearly between the two.   The mid-mount mower according to claim 8, further comprising a first lock mechanism that locks the coupling holding portion at the connection position.   The mid-mount mower according to any one of claims 1 to 9, further comprising a second lock mechanism that locks the engagement portion and the engaged portion at the engagement position. A first lock mechanism that locks the coupling holding portion at the connection position, and a second lock mechanism that locks the engagement portion and the engaged portion at the engagement position;
The first lock mechanism and the second lock mechanism have a common rotation operation shaft, and the first lock mechanism is coupled to the coupling by a rotation displacement of a first action portion provided on the rotation operation shaft. The holding portion is locked at the connection position, and the second locking mechanism causes the engagement portion and the engaged portion to move to the engagement position by the rotation displacement of the second action portion provided on the rotation operation shaft. The mid-mount mower according to claim 8, which is locked by a rocker.   The mid-mount mower according to claim 11, wherein the rotation operation with respect to the rotation operation shaft is performed by an operation arm extending to the periphery of the driver seat.   The blade housing is provided with a gauge wheel unit for changing the ground height of the blade housing, and the gauge wheel unit can be switched to a set position that creates a different ground height. The mid-mount mower according to any one of claims 1 to 12, wherein a position where at least a part of the blade housing is brought into ground contact is included.

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