WO2023276372A1

WO2023276372A1 - Walk-behind cultivator

Info

Publication number: WO2023276372A1
Application number: PCT/JP2022/015127
Authority: WO
Inventors: 大地亀田; 伸治前田; 剛渡; 栄作森田
Original assignee: 株式会社クボタ
Priority date: 2021-06-28
Filing date: 2022-03-28
Publication date: 2023-01-05
Also published as: KR20240026152A

Abstract

Provided is a walk-behind cultivator having a clutch lever that returns to an initial position when not in operation, wherein the engine can be prevented from starting up in a state in which the clutch lever is being operated.　The present invention comprises: a clutch lever 40 that can be operated so as to swing between an initial position and an operation position, that switches a clutch mechanism 10 to a motive power transmittable state when switched to the operation position, and that switches the clutch mechanism 10 to a motive power non-transmittable state when switched to the initial position; and a startup restraint mechanism 100 that restrains the startup of an engine 4 if it is detected that the clutch lever 40 has been switched to the operation position.

Description

Walking type management machine

The present invention relates to the technology of a walk-behind management machine equipped with a clutch lever.

Conventionally, the technology of walk-behind management machines equipped with clutch levers is publicly known. For example, it is as described in Patent Document 1.

Patent Document 1 discloses a walk-behind tending machine that includes a main clutch mechanism capable of transmitting power from the engine to the running wheels, and a dead man's clutch lever that engages and disengages the power transmission of the main clutch mechanism. The dead man's clutch lever is swingable between a clutch engagement position and a clutch release position displaced above the clutch engagement position around the pivot shaft. Also, the dead man's clutch lever is biased toward the clutch release position so as to return to the clutch release position when not operated.

In the walk-behind management machine described above, the engine is generally started with the clutch disengaged. The operator can operate the walk-behind tending machine by operating the deadman's clutch lever to engage the clutch after starting the engine.

However, in the walking type tending machine, if the engine is started while the deadman's clutch lever is being operated, the walking type tending machine may start moving unintentionally. Therefore, there is a demand for a technique for preventing the engine from starting while the deadman's clutch lever is being operated.

JP 2015-97491 A

One aspect of the present disclosure has been made in view of the above situation, and the problem to be solved is to provide a walk-behind tending machine having a clutch lever that returns to an initial position when not operated, in which the clutch lever is To provide a walking type management machine capable of preventing an engine from starting while being operated.

The problem to be solved by one aspect of the present disclosure is as described above, and the means for solving this problem will now be described.

That is, in the walk-behind tending machine according to one aspect of the present disclosure, the swing operation is possible between the initial position and the operating position, and in the state switched to the operating position, the clutch mechanism is in a state capable of transmitting power. a clutch lever that switches the clutch mechanism to a state in which power cannot be transmitted when the clutch mechanism is switched to the initial position; and a check mechanism.

Further, the start restraint mechanism includes a link mechanism having a plurality of link members that are displaced according to swinging of the clutch lever, and by detecting displacement of the link mechanism, the clutch lever is switched to the operating position. and a detection unit for detecting that it has been received.

Further, the plurality of link members include detected members to be detected by the detection unit, and the detected members are displaced at a swing angle smaller than the swing angle of the clutch lever. .

In addition, the plurality of link members further include a connecting member that is rotatably connected to each of the detected member and the vehicle body.

Further, the detected member is formed at a connected portion connected to the clutch lever and the connecting member, and a position displaced toward the inside of the vehicle body with respect to the connected portion, and is detected by the detecting portion. and a part.

In addition, the member to be detected is arranged so that at least a part thereof overlaps with the detecting portion in a side view regardless of whether the clutch lever swings.

Further, in the walk-behind management machine according to an aspect of the present disclosure, the distance from the connecting portion between the clutch lever and the member to be detected to the connecting portion between the member to be detected and the connecting member is equal to the member to be detected and It is formed so as to be longer than the distance from the connecting portion with the connecting member to the detected portion.

A walk-behind management machine according to an aspect of the present disclosure further includes a cover member that covers the detection unit from above.

As an effect of one aspect of the present disclosure, the following effects are obtained.

According to one aspect of the present disclosure, in a walk-behind maintenance machine having a clutch lever that returns to the initial position when not operated, it is possible to prevent the engine from starting while the clutch lever is being operated.

Further, according to one aspect of the present disclosure, it is possible to restrain the start of the engine according to the displacement of the link mechanism interlocked with the swinging of the clutch lever.

Further, according to one aspect of the present disclosure, by keeping the swing angle of the member to be detected smaller than the swing angle of the clutch lever, it is possible to save space in the movable range of the member to be detected.

Further, according to one aspect of the present disclosure, it is possible to suppress the displacement of the member to be detected.

Further, according to one aspect of the present disclosure, it is possible to prevent the detection unit from interfering with obstacles (crops, trees, etc.) outside the vehicle body.

Further, according to one aspect of the present disclosure, it is possible to save space in the movable range of the member to be detected.

In addition, according to one aspect of the present disclosure, it is possible to suppress the displacement of the detected part due to the operation of the clutch lever.

Further, according to one aspect of the present disclosure, it is possible to suppress adhesion of moisture and dust to the detection unit.

BRIEF DESCRIPTION OF THE DRAWINGS The side view which showed the walking type management machine which concerns on 1st embodiment of this invention. FIG. 2 is a block diagram showing a configuration relating to engine start-up of the walk-behind management machine; The side view which showed the clutch mechanism typically. FIG. 4 is a side view showing the walk-behind tending machine with the clutch lever positioned at the initial position; FIG. 3 is a perspective view showing a steering handle and a start restraint mechanism; FIG. 4 is an enlarged perspective view showing a steering handle and a start restraint mechanism; The bottom view which showed the steering handle and the start restraint mechanism. The bottom perspective view which showed the steering handle and the starting check mechanism. FIG. 3 is an exploded perspective view showing a link mechanism; The side view which showed the link mechanism. FIG. 4 is a side view showing the walk-behind tending machine with the clutch lever positioned at the operating position; The side view which showed the start restraint mechanism which concerns on the modification of this invention. The side view which showed the walking type management machine which concerns on 2nd embodiment. The front perspective view which showed a part of shaft and gear provided in the transmission case. Similarly, a rear perspective view. Also a side view. The perspective view which shows the structure which switches the propriety of power transmission, etc.. FIG. Also a side view. Also a front view. Similarly, the front exploded perspective view. (a) A perspective view showing a PTO gear. (b) Similarly, a side view. (a) A perspective view showing a PTO shifter. (b) Similarly, a side view. (c) Similarly, a front view. FIG. 4 is a schematic cross-sectional view showing claw portions of a PTO gear and a PTO shifter; (a) A perspective view showing a differential sprocket. (b) Similarly, a side view. (a) An exploded perspective view showing an advance/retreat mechanism. (b) Similarly, front cross-sectional view. (a) A perspective view showing a differential lock shifter. (b) Similarly, a side view. (c) Similarly, a front view. FIG. 3 is a schematic cross-sectional view showing a differential sprocket and an advancing/retreating mechanism; The perspective view which shows a shift fork. (a) Similarly, a side view. (b) Similarly, a front view. (a) A schematic cross-sectional view showing a state in which the claw portion of the PTO shifter is close to the claw portion of the PTO gear. (b) A schematic cross-sectional view showing a state in which the differential sprocket and the pin of the advance/retreat mechanism are engaged. (a) A schematic cross-sectional view showing a state in which the PTO gear and claw portions of the PTO shifter are engaged. (b) A schematic cross-sectional view showing a state in which the differential sprocket and the pin of the advance/retreat mechanism are engaged. (a) A schematic cross-sectional view showing a state before the claw portions of the PTO gear and the PTO shifter are engaged with each other. (b) A schematic cross-sectional view showing a state in which the ridges of the differential sprocket and the pin of the advancing/retreating mechanism are in contact with each other. (a) A schematic cross-sectional view showing a state in which the PTO gear and claw portions of the PTO shifter are engaged. (b) A schematic cross-sectional view showing a state in which the pin of the advancing/retreating mechanism is retracted. FIG. 4 is a cross-sectional front view showing how the pin of the advancing/retreating mechanism is pressed by the trough portion of the differential sprocket; Front sectional drawing which shows the modification of a pin.

Hereinafter, the directions indicated by arrow U, arrow D, arrow F, arrow B, arrow L, and arrow R in the drawings are defined as upward, downward, forward, backward, leftward, and rightward, respectively. will be explained.

A walk-behind management machine 1 according to a first embodiment of the working machine of the present invention will be described below with reference to FIGS. 1 to 3. FIG.

The walking type maintenance machine 1 includes a body frame 2, wheels 3, an engine 4, a fuel tank 5, a bonnet 6, a transmission case 7, a rotary tillage device 8, a clutch mechanism 10, a handle frame 11, a handle connecting portion 12, an operation handle 20, It comprises a start restraint mechanism 100, a safety unit 130, and the like.

The body frame 2 shown in FIG. 1 is a member formed by appropriately bending a plate material. The body frame 2 is supported by a pair of left and right wheels 3 . The engine 4 is mounted on the body frame 2 . The fuel tank 5 is arranged behind the engine 4 . The engine 4 and fuel tank 5 are covered with a bonnet 6 . The engine 4 is started when the ignition plug 4b is operated by the electric current sent via the igniter 4a shown in FIG. The safety unit 130 permits the energization of the ignition plug 4b from the igniter 4a. A detailed description of the safety unit 130 will be given later.

The transmission case 7 shown in FIG. 1 is a case that houses a power transmission mechanism (not shown) that transmits power from the engine 4 to the wheels 3 and the rotary tillage device 8. A rotary tillage device 8 is provided at the rear of the transmission case 7 . The rotary tillage device 8 has a tillage claw 9 fixed to the rotary shaft. The upper part of the tillage tines 9 is covered with a tillage cover 9a.

The clutch mechanism 10 is for switching between rotating and stopping the rotation of the wheels 3 and the tillage tines 9 . As the clutch mechanism 10 of the present embodiment, as shown in FIG. 3, a belt 10c wound around a first pulley 10a on the engine 4 side and a second pulley 10b on the transmission case 7 side has a tension pulley 10d. A so-called belt tension clutch is assumed in which power can be transmitted by applying tension through the belt. The tension pulley 10d is displaceably provided between a position for applying tension to the belt 10c (tension applying position) and a position for releasing the application of tension to the belt 10c (release position). Also, the tension pulley 10d is biased toward the release position by the biasing force of an appropriate spring member.

As shown in FIG. 1, a handle frame 11 is arranged above the tillage cover 9a. The handle frame 11 is a frame for supporting the steering handle 20 . The handle frame 11 is formed to extend rearward and upward. A steering handle 20 is attached to the rear upper end portion of the handle frame 11 via a handle connecting portion 12 . The control handle 20 is provided with a start restraint mechanism 100 that switches the engine 4 between a startable state and a non-startable state. A detailed description of the steering handle 20 and the start restraint mechanism 100 will be given later.

The steering handle 20 will be described below using FIGS. 2 to 11. FIG. The steering handle 20 is for the operator to steer the walk-behind tending machine 1 . The steering handle 20 includes a handle body 30 , a clutch lever 40 , a cover portion 50 , a main switch 60 , an operating lever 70 and a throttle lever 80 .

A handle main body 30 shown in FIGS. 4 and 5 is the main structure of the steering handle 20 . The handle body 30 is formed in a substantially triangular frame (frame) shape in plan view. The handle body 30 is formed to extend rearward and upward from the handle connecting portion 12 . The handle body 30 is formed by appropriately bending a substantially circular member when viewed in cross section. The handle body 30 has a side portion 31 and a grip portion 34 .

The side portion 31 is a portion that constitutes the left and right side portions of the handle body 30 . The side portions 31 extend rearward (rear upward) from the handle connecting portion 12 so as to be separated from each other in the left-right direction. The side portion 31 comprises a first connecting portion 32 and a second connecting portion 33 .

A first connecting portion 32 shown in FIGS. 5 to 9 is a portion to which a clutch lever 40, which will be described later, is connected. The first connecting portion 32 is provided on each of the left and right side portions 31 . The first connecting portion 32 is provided on the lower surface of the rear portion of the side portion 31 . The first connecting portion 32 is formed by appropriately bending a plate-shaped member. The first connecting portion 32 has a fixing portion 32a and an extending portion 32b.

A fixing portion 32a shown in FIGS. 6 to 9 is a portion fixed to the lower surface of the side portion 31. FIG. The fixed portion 32a is formed so that the plate surface faces substantially in the vertical direction.

The extending portions 32b are portions extending downward from both left and right end portions of the fixed portion 32a. The extending portion 32b is formed so that the plate surface faces in the left-right direction. The extending portion 32b has a connecting hole 32c.

A connecting hole 32c shown in FIG. 9 is a hole penetrating the extending portion 32b in the left-right direction. A pin A is inserted through the connecting hole 32c with its axial direction oriented in the left-right direction.

A second connecting portion 33 shown in FIGS. 6 to 9 is a portion to which a connecting member 115, which will be described later, is connected. The second connecting portion 33 is provided on the right side portion 31 of the handle body 30 on which the start restraint mechanism 100 is arranged, that is, the left and right side portions 31 . The second connecting portion 33 is provided forwardly of the first connecting portion 32 so as to extend downward (diagonally rearward and downward) from the lower surface of the side portion 31 . The second connecting portion 33 is formed in a substantially plate shape with its plate surface directed in the left-right direction. The second connecting portion 33 has a connecting hole 33a.

A connecting hole 33a shown in FIG. 9 is a hole penetrating the second connecting portion 33 in the left-right direction.

A grip portion 34 shown in FIGS. 4 and 5 is a portion that constitutes the rear portion of the handle body 30 . The grip portion 34 extends in the left-right direction so as to connect rear end portions of the left and right side portions 31 . The grip portion 34 is gripped by the fingers of the operator.

A clutch lever 40 shown in FIGS. 4, 5, 8, 9, and 11 is a lever capable of switching (switching operation) the clutch mechanism 10 between a state in which power can be transmitted and a state in which power cannot be transmitted. is. The clutch lever 40 is formed in a substantially U-shaped frame (frame) shape when viewed from the front. The clutch lever 40 is formed by appropriately bending a substantially circular member when viewed in cross section.

As shown in FIG. 5, the clutch lever 40 is provided between the left and right side portions 31 of the handle body 30 in the middle (rear portion) in the front-rear direction. Further, as shown in FIGS. 4 and 11, the clutch lever 40 is in an initial position ( 4) and an operating position (see FIG. 11) in which it is laid down along the handle body 30. As shown in FIG. A detailed description of the switching operation by the clutch lever 40 will be given later. Below, the configuration of the clutch lever 40 will be described with reference to the initial position. The clutch lever 40 has a side portion 41 , a grip portion 43 and a wire 44 .

The side portion 41 shown in FIGS. 4, 5, 8 and 9 constitutes both left and right side portions of the clutch lever 40. The side portion 41 is formed to extend generally vertically. The lower portion 42 is formed in a substantially plate shape with the plate surface directed in the left-right direction. In this embodiment, of the lower portions 42 of the left and right side portions 41 , the lower portion 42 of the right side portion 41 extends downward more than the lower portion 42 of the left side portion 41 . The side portion 41 has a first connecting hole 42a and a second connecting hole 42b.

The first connecting hole 42a shown in FIG. 9 is a hole penetrating through the lower portion 42 in the left-right direction. The first connecting holes 42a are formed in the left and right side portions 41, respectively. The pin A inserted through the connecting hole 32c of the first connecting portion 32 is inserted through the first connecting hole 42a. An appropriate nut N that functions as a retainer is fixed to the tip of the pin A inserted through the first connecting hole 42a and the connecting hole 32c (see FIG. 8). In this manner, the lower portion 42 of the side portion 41 is connected to the left and right side portions 31 of the handle body 30 so as to be capable of swinging.

The second connecting hole 42b is a hole that passes through the lower portion 42 in the left-right direction below the first connecting hole 42a (the lower end of the side portion 41). The second connecting hole 42 b is formed in the lower portion 42 of the right side portion 41 of the left and right side portions 41 .

A grip portion 43 shown in FIGS. 4 and 5 is a portion that constitutes the upper portion of the clutch lever 40 . The grip portion 43 extends in the left-right direction so as to connect upper end portions of the left and right side portions 41 . The grip portion 43 is gripped by the fingers of the operator. Further, the grip portion 43 is provided with an appropriate grip that covers the grip portion 43 .

A wire 44 shown in FIGS. 3 and 5 is a portion connected to the clutch mechanism 10 . As shown in FIG. 5 , one end of the wire 44 is connected above the first connecting hole 42 a in the left side portion 41 of the left and right side portions 41 . The other end of the wire 44 is connected to the tension pulley 10d of the clutch mechanism 10, as shown in FIG. A spring portion 44a constituting a tension spring is provided at the other end portion of the wire 44, and the spring portion 44a is fixed to the tension pulley 10d. Due to the urging force of the spring portion 44a, the clutch lever 40 always receives a restoring force that returns it from the operating position to the initial position.

The cover part 50 shown in FIGS. 6 to 8 is provided with a main switch 60, an operation lever 70, a detection part 120, etc., which will be described later, and covers at least part of these members from above. The cover portion 50 is provided on the left surface of the right side portion 31 of the left and right side portions 31 of the handle body 30 . The cover part 50 has a cover member 51 and a stay 52 .

The cover member 51 is a portion that covers at least a portion of the main switch 60, the operating lever 70, and the detection section 120 from above. The cover member 51 is formed in a substantially box shape that opens downward. The cover portion 50 is formed in a substantially rectangular shape elongated in the front-rear direction in plan view. The cover member 51 is made of resin. The cover member 51 is arranged in front of the first connecting portion 32 of the side portion 31 of the handle body 30 and over the front and rear of the second connecting portion 33 . The cover member 51 has a switch insertion hole 51a and a long hole 51b.

A switch insertion hole 51a shown in FIGS. 6 and 7 is a hole through which a part (switch portion) of a main switch 60, which will be described later, is inserted. The switch insertion hole 51a penetrates the cover member 51 in the vertical direction. The switch insertion hole 51 a is formed in the rear portion of the cover member 51 .

The long hole 51b is a hole through which an operation lever 70, which will be described later, is inserted. The long hole 51b penetrates the cover member 51 in the vertical direction. The long hole 51b is formed in a shape elongated in the front-rear direction. The long hole 51b is formed in front of the switch insertion hole 51a.

A stay 52 shown in FIGS. 7 and 8 is a portion that is fixed to the side portion 31 of the handle body 30 and to which the cover member 51 is fixed. The stay 52 is formed by appropriately bending a plate-shaped member. The stay 52 is made of metal. The stay 52 includes a cover fixing portion 52a, a handle fixing portion 52b, and a detecting portion fixing portion 52c.

A cover fixing portion 52a shown in FIG. 8 is a portion to which the cover member 51 is fixed. The cover fixing portion 52a is formed so that the plate surface faces in the vertical direction. The cover member 51 is fixed to the cover fixing portion 52a by appropriate fasteners such as screws while being placed on the upper surface of the cover fixing portion 52a.

The handle fixing portion 52b is a portion fixed to the left surface of the right side portion 31. The handle fixing portion 52b is formed so that the plate surface faces in the left-right direction. The handle fixing portion 52b is formed to extend downward from the right end portion of the cover fixing portion 52a. The handle fixing portion 52b is fixed to the left surface of the side portion 31 by welding or the like.

The detecting portion fixing portion 52c is a portion to which the detecting portion 120 of the start restraining mechanism 100, which will be described later, is fixed. The detecting portion fixing portion 52c is formed in a substantially U shape with an opening on the right side when viewed in the front-rear direction. The detecting portion fixing portion 52c has its upper surface fixed to the lower end portion of the handle fixing portion 52b, and the detecting portion 120 fixed to its lower surface.

The main switch 60 shown in FIGS. 2 and 6 is a switch that can be operated to switch between a state in which the engine 4 can be started and a state in which the engine 4 is stopped. The main switch 60 is switched between an operating position at which the engine 4 can be started and a stop position at which the engine 4 is stopped by an appropriate rotating operation. Further, the main switch 60 can be pressed in addition to the rotating operation. The main switch 60 can be switched from the operating position to the stop position by being pressed. The operable portion (switch portion) of the main switch 60 is exposed through the switch insertion hole 51a of the cover member 51, and the other portion is covered by the cover member 51 from above.

When starting the engine 4, the operator operates a proper recoil starter (not shown) or a starting switch (not shown) for starting the engine 4 with the main switch 60 set to the operating position. conduct. As a result, the ignition plug 4b is actuated by the current sent through the igniter 4a shown in FIG. 2, and the engine 4 is started.

The operation lever 70 shown in FIG. 6 is a lever capable of switching the operation of the walking type tending machine 1 . Specifically, the operation lever 70 can switch between on/off of the differential lock and driving/stopping of the rotary tillage device 8 by an appropriate swinging operation. A portion of the operation lever 70 that is gripped by the fingers of the operator is exposed through the long hole 51b of the cover member 51, and the other portion is covered with the cover member 51 from above. The operating lever 70 can be operated to swing back and forth along the elongated hole 51b.

The throttle lever 80 is a lever that can be operated to control the output (rotational speed) of the engine 4. The throttle lever 80 has an appropriate sensor that detects the amount of operation of the lever. As the throttle lever 80, a lever that can be rotated appropriately can be used. The throttle lever 80 is provided on the right side portion 31 of the left and right side portions 31 of the handle body 30 . Also, the throttle lever 80 is arranged to the right of the main switch 60 .

A switching operation of the clutch mechanism 10 using the clutch lever 40 as described above will be described below.

As shown in FIGS. 4 and 11, when the operator grips the clutch lever 40 together with the handle body 30, the clutch lever 40 engages the pin A inserted through the connecting hole 32c (first connecting portion 32). As viewed from the right side, it swings counterclockwise about the swing center, and displaces from the initial position to the operating position. The swing angle of the clutch lever 40 is about 60 degrees. As shown in FIG. 3, as the clutch lever 40 swings, the tension pulley 10d is pulled by the wire 44 and displaced toward the tension applying position. At this time, tension is applied to the belt 10c to operate the clutch mechanism 10, so that power from the engine 4 is transmitted to the wheels 3 and the rotary tillage device 8 via the power transmission mechanism of the transmission case 7. switched to the enabled state. That is, the clutch mechanism 10 is switched to a state in which power can be transmitted. As a result, the walk-behind tending machine 1 can travel or rotate the tillage tines 9 to till the field.

When the operator releases the clutch lever 40, the spring portion 44a of the wire 44 shown in FIG. Rotates clockwise in right side view around the pin A inserted through the . As a result, the clutch lever 40 automatically returns from the operating position to the initial position. When the clutch lever 40 returns to the initial position, the tension pulley 10d is displaced toward the release position by the urging force of an appropriate spring member. At this time, the application of tension to the belt 10c is stopped, so that the clutch mechanism 10 is switched to a state in which the power cannot be transmitted. As a result, the rotation of the wheels 3 and the tillage tines 9 is stopped.

As described above, in the walk-behind tending machine 1 according to the present embodiment, the clutch mechanism 10 operates while the operator is holding the handle body 30 and the clutch lever 40 (a so-called dead man's clutch lever), and the operator releases the hand. A so-called deadman clutch is employed in which the clutch mechanism 10 stops when the operation of the clutch lever 40 is released.

The start restraint mechanism 100 will be described below.

The start restraint mechanism 100 shown in FIGS. 4 and 6 to 10 switches the engine 4 between a startable state and a non-startable state according to the rocking motion of the clutch lever 40 . Specifically, when the start restraint mechanism 100 detects that the clutch lever 40 has been switched to the initial position, it switches the engine 4 to a startable state. Further, when the start restraint mechanism 100 detects that the clutch lever 40 has been switched to the operating position, the start restraint mechanism 100 switches the engine 4 to a state in which it cannot be started (prevents the start of the engine 4). The start restraint mechanism 100 is provided on the right side portion 31 of the left and right side portions 31 of the handle body 30 . The start restraint mechanism 100 has a link mechanism 110 and a detection section 120 .

The link mechanism 110 has a plurality of link members that are displaced according to the rocking of the clutch lever 40 . The link mechanism 110 includes detected members 111 and connecting members 115 as a plurality of link members.

The member to be detected 111 shown in FIGS. 6 to 10 is to be detected by the detecting section 120, which will be described later. The detected member 111 is rotatably connected to each of the clutch lever 40 and a connecting member 115, which will be described later. The detected member 111 is formed by appropriately bending a plate-shaped member. The member to be detected 111 includes a connecting portion 112 , a connecting portion 113 and a portion to be detected 114 .

The connected portion 112 is a portion connected to the clutch lever 40 and the connecting member 115 . The connected part 112 is formed in a shape elongated in the front-rear direction (the oblique front-rear direction). More specifically, the connected portion 112 is formed to extend obliquely forward and downward from the rear end portion to the front end portion. The connected part 112 is formed so that the plate surface faces in the left-right direction.

As shown in FIG. 8, the connected portion 112 is arranged on the right side of the clutch lever 40 (side portion 41) and on the left side of the second connecting portion 33 of the handle body 30 (side portion 31). The connected part 112 has a first connecting hole 112a and a second connecting hole 112b.

The first connecting hole 112a shown in FIG. 9 is a hole penetrating the rear end portion of the connected portion 112 in the left-right direction. The pin C inserted through the second connecting hole 42b of the clutch lever 40 (side portion 41) is inserted through the first connecting hole 112a. An appropriate nut N that functions as a retainer is fixed to the tip of the pin C inserted through the first connecting hole 112a and the second connecting hole 42b (see FIG. 8). In this manner, the rear end portion of the connected portion 112 is connected to the lower end portion of the clutch lever 40 (side portion 41).

The second connecting hole 112b is a hole penetrating through the front end portion of the connected portion 112 in the left-right direction.

The connection part 113 is a part that connects the connection part 112 and the detection part 114 described later. The connecting portion 113 is formed to extend leftward from the front end portion of the connected portion 112 . The connecting portion 113 is formed so that the plate surface faces obliquely forward and downward.

The detected part 114 is a part detected by the detection unit 120, which will be described later. Detected portion 114 is formed to extend obliquely forward and downward from the left end portion (tip portion) of connection portion 113 . The detected part 114 extends obliquely forward and downward with respect to the extending direction of the connected part 112 . Detected portion 114 is formed so that the plate surface faces in the left-right direction. Detected portion 114 is formed in a substantially rectangular shape in a side view.

As shown in FIG. 7, the detected portion 114 is formed at a position displaced toward the inside (left side) of the vehicle body with respect to the connected portion 112 . In other words, the detected portion 114 is located inside (left side) of the vehicle body with respect to the connected portion 112 by the extension dimension of the connecting portion 113 .

The connecting member 115 shown in FIGS. 6 to 10 is rotatably connected to the detected member 111 and the second connecting portion 33 of the handle body 30 (side portion 31). The connecting member 115 is formed in a substantially plate shape with its plate surface directed in the left-right direction. The connecting member 115 is formed in an oval shape extending obliquely forward and upward from the rear end to the front end in a side view.

As shown in FIG. 9, the connecting member 115 is arranged on the left side of the second connecting portion 33 and on the right side of the member 111 to be detected. The connecting member 115 has a first connecting hole 115a and a second connecting hole 115b.

The first connecting hole 115a shown in FIG. 9 is a hole penetrating the front end portion (upper end portion) of the connecting member 115 in the left-right direction. The pin B inserted through the connecting hole 33a of the second connecting portion 33 is inserted through the first connecting hole 115a. An appropriate nut N that functions as a retainer is fixed to the tip of the pin B inserted through the first connecting hole 115a and the connecting hole 33a (see FIG. 8). In this manner, the front end portion (upper end portion) of the connecting member 115 is connected to the second connecting portion 33 .

The second connecting hole 115b is a hole penetrating through the rear end (lower end) of the connecting member 115 in the left-right direction. A pin D that is inserted through the second connecting hole 112b of the connected portion 112 is inserted through the second connecting hole 115b. An appropriate nut N that functions as a retainer is fixed to the tip of the pin D inserted through the second connecting hole 115b and the second connecting hole 112b (see FIG. 8). In this manner, the rear end (lower end) of the connecting member 115 is connected to the front end of the connecting portion 112 of the detected member 111 .

The detection unit 120 shown in FIGS. 4, 6 to 8, and 11 detects pressing by the detection target part 114 of the detection target member 111. FIG. As shown in FIG. 8, the detector 120 is fixed to the detector fixing portion 52c of the cover portion 50 (stay 52). The detector 120 is fixed to the lower surface of the detector fixing portion 52c. The detection unit 120 is positioned to the left of the detected member 111 (detected portion 114).

The detection unit 120 is covered from above by the cover member 51 of the cover unit 50 . Accordingly, it is possible to prevent moisture and dust from adhering to the detection unit 120 . Further, in this embodiment, the cover member 51 used as a guide for the operation lever 70 and a cover for the main switch 60 and the operation lever 70 is also used as a cover for the detection unit 120 . As a result, an increase in the number of parts can be suppressed.

The detection unit 120 has a lever portion 121 that is displaced in response to pressure from the detected portion 114 , and detects the pressure from the detected portion 114 based on the displacement of the lever portion 121 . As shown in FIG. 8 , the lever portion 121 is arranged on the right side of the detecting portion 120 on the detected portion 114 side (right side). The lever portion 121 is arranged so as to incline rightward as it goes to the rear side.

The lateral position of the tip (rear end) of the lever portion 121 is substantially the same as the lateral position of the detected portion 114 . Therefore, as shown in FIGS. 4 and 8, when the tip of the lever portion 121 overlaps the detected portion 114 of the detected member 111 in a side view, the lever portion 121 is moved by the detected portion 114. pressed. In the following description, the state in which the detection unit 120 is detecting the pressure of the detection site 114 is ON, and the state in which the detection unit 120 is not detecting the pressure is OFF.

As the detection unit 120, various switches capable of detecting pressing such as an appropriate limit switch (microswitch) can be employed. It should be noted that the detection unit 120 is not limited to a switch capable of detecting pressing, and a non-contact switch can also be employed.

The safety unit 130 shown in FIG. 2 is capable of switching between permission and interruption of energization from the igniter 4a to the ignition plug 4b. The safety unit 130 is electrically connected to the main switch 60, the detector 120, and the igniter 4a via appropriate harnesses (not shown).

Based on the states of the main switch 60 and the detection unit 120, the safety unit 130 switches between permission and interruption of energization from the igniter 4a to the spark plug 4b. Specifically, when the main switch 60 is in the operating position and the detection unit 120 is on (pressed by the part 114 to be detected), the safety unit 130 switches the ignition plug from the igniter 4a. 4b is allowed to be energized. In addition, the safety unit 130 cuts off the energization from the igniter 4a to the spark plug 4b in cases other than the above state. That is, in the present embodiment, when the detecting portion 120 is off (not pressed by the portion 114 to be detected), the energization from the igniter 4a to the spark plug 4b is interrupted. In this case, even if the operator performs an operation to start the engine 4 (for example, a recoil operation), the spark plug 4b does not operate and the engine 4 does not start.

The operation of the link mechanism 110 accompanying the swinging of the clutch lever 40 will be described below.

First, the relationship between the connecting portions of the members of the link mechanism 110 as described above will be described. Here, hereinafter, as shown in FIG. 10, the distance from the connecting portion (pin C) between the clutch lever 40 and the detected member 111 to the connecting portion (pin D) between the detected member 111 and the connecting member 115 is is called the distance L1. Further, the distance from the connecting portion (pin D) between the member to be detected 111 and the connecting member 115 to the portion to be detected 114 (the central portion of the portion to be detected 114 in side view) is referred to as a distance L2.

Also, the distance from the connecting portion (pin A) between the clutch lever 40 and the first connecting portion 32 of the side portion 31 to the connecting portion (pin C) between the clutch lever 40 and the detected member 111 is referred to as a distance L3. Further, the distance from the connecting portion (pin B) between the second connecting portion 33 of the side portion 31 and the connecting member 115 to the connecting portion (pin D) between the detected member 111 and the connecting member 115 is referred to as a distance L4.

The link mechanism 110 can displace the detected member 111 in conjunction with the swinging of the clutch lever 40 . Specifically, as shown in FIG. 10, the connecting portion (pin C) of the detected member 111 to the clutch lever 40 can be displaced within the range of an arc with the pin A as the swing center and the distance L3 as the radius. is. Further, the connecting portion (pin D) of the detected member 111 with the connecting member 115 can be displaced within the range of an arc with the pin B as the swing center and the distance L4 as the radius.

Next, the operation of the link mechanism 110 when swinging the clutch lever 40 from the initial position to the operating position will be described.

FIG. 4 shows a state in which the clutch lever 40 is located at the initial position. In this state, the clutch mechanism 10 cannot transmit power. Further, in this state, as shown in FIGS. 4, 8 and 10, the tip of the lever portion 121 overlaps the detected portion 114 in a side view. That is, in this state, the detection unit 120 detects the pressing force of the detection target part 114 of the detection target member 111 .

In this case, since the detection unit 120 is on, the safety unit 130 permits energization from the igniter 4a to the spark plug 4b when the main switch 60 is in the operating position. In this case, the engine 4 is started by the operator's starting operation (for example, recoil operation) of the engine 4 .

When the operator grasps the clutch lever 40 together with the handle body 30 and swings the clutch lever 40 from the initial position to the operating position, the clutch lever 40 swings to the right with the pin A as the swing center, as shown in FIG. Displaces counterclockwise when viewed from above. Interlocking with the displacement, the connection portion (pin C) of the detected member 111 with the clutch lever 40 is displaced obliquely forward and upward within an arc range with the pin A as the swing center and the distance L3 as the radius. . In conjunction with the displacement, the connecting portion (pin D) of the member 111 to be detected and the connecting member 115 moves obliquely forward and downward within the range of an arc with the pin B as the swing center and the distance L4 as the radius. Displace (see Figure 10).

In this way, in conjunction with the rocking motion of the clutch lever 40, the member to be detected 111 rocks clockwise as a whole as viewed from the right side and is displaced forward. In this embodiment, by limiting the movable range of the member to be detected 111 by the connecting member 115, the displacement of the member to be detected 111 can be suppressed. Further, the swing angle of the detected member 111 is about 25 degrees. Thus, the detected member 111 is displaced at a swing angle smaller than the swing angle of the clutch lever 40 (about 60 degrees). According to this, the space saving of the movable range of the detected member 111 can be achieved.

FIG. 11 shows a state where the clutch lever 40 is positioned at the operating position. In this state, the clutch mechanism 10 can transmit power. Further, in this state, the detected portion 114 of the detected member 111 is positioned in front of the lever portion 121 of the detection portion 120 . That is, in side view, the tip of the lever portion 121 does not overlap the detected portion 114 . In this case, the pressing of the detecting portion 120 by the detected portion 114 is released. Therefore, the detection unit 120 does not detect pressing by the detection target part 114 of the detection target member 111 .

As shown in FIGS. 10 and 11, even in this case, at least a portion of the member to be detected 111 (the front end portion of the portion to be connected 112) overlaps with the detecting portion 120 in side view. That is, in the present embodiment, the detected member 111 is arranged so that at least a portion thereof overlaps with the detecting portion 120 regardless of whether the clutch lever 40 swings. As a result, the movable range of the detected member 111 can be reduced in space.

When the detection unit 120 does not detect pressing by the detected part 114, the detection unit 120 is off, so the safety unit 130 cuts off the energization from the igniter 4a to the spark plug 4b when the engine 4 is stopped. In this case, even if the operator performs an operation to start the engine 4 (for example, a recoil operation), the spark plug 4b does not operate and the engine 4 does not start.

Next, the operation of the link mechanism 110 when swinging the clutch lever 40 from the operating position to the initial position will be described.

When the operator releases the clutch lever 40, the return force of the spring portion 44a of the wire 44 automatically displaces the clutch lever 40 clockwise around the pin A as the swing center. In conjunction with the above-described displacement, the connecting portion (pin C) of the detected member 111 with the clutch lever 40 is displaced obliquely rearward and downward, contrary to the movement from the initial position to the operating position. The connecting portion (pin D) with the connecting member 115 is displaced obliquely rearward and upward (see FIG. 10).

In this manner, in conjunction with the rocking motion of the clutch lever 40, the detected member 111 as a whole rotates counterclockwise in a right side view and is displaced rearward. As a result, the detected portion 114 of the detected member 111 presses the detecting portion 120 .

According to the walk-behind tending machine 1 having the start restraint mechanism 100 as described above, it is possible to prevent the engine 4 from starting while the clutch lever 40 is being operated (switched to the operating position). . As a result, even if the engine 4 is started while the clutch lever 40 is being operated (the clutch mechanism 10 is capable of transmitting power), the walk-behind management machine 1 will not suddenly start. can be suppressed.

Further, as shown in FIG. 10, the link mechanism 110 according to this embodiment is formed so that the distance L1 is longer than the distance L2. As a result, the displacement of the detected portion 114 due to the operation of the clutch lever 40 can be kept small, and the movable range of the detected member 111 can be made smaller.

In addition, the detected part 114 according to the present embodiment is formed at a position displaced toward the inside (left side) of the vehicle body with respect to the connected part 112 . As a result, it is possible to prevent the detector 120 from interfering with obstacles (crops, trees, etc.) outside the vehicle body. In addition, it is possible to suppress dust from the outside of the vehicle body from adhering to detection unit 120 .

Further, when the start restraint mechanism 100 according to the present embodiment is displaced in conjunction with the operation of the clutch lever 40, it moves above the handle body 30 and the clutch lever 40 (protrudes upward from the handle body 30 and the like). ) never. As a result, interference between the start restraint mechanism 100 and other members (for example, the cover portion 50, etc.) can be avoided.

As described above, the walk-behind management machine 1 according to the present embodiment is
A swing operation is possible between an initial position and an operating position, the clutch mechanism 10 is switched to a state in which power can be transmitted when switched to the operating position, and the clutch mechanism 10 is switched to the initial position. a clutch lever 40 that switches to a state in which power transmission is disabled;
a start restraint mechanism 100 that restrains the start of the engine 4 when it is detected that the clutch lever 40 has been switched to the operating position;
is provided.

With this configuration, in the walking type maintenance machine 1 having the clutch lever 40 (so-called dead man's clutch lever) that returns to the initial position when not operated, the clutch lever 40 is operated (switched to the operating position). ), it is possible to prevent the engine 4 from starting.

Further, the start restraint mechanism 100 is
a link mechanism 110 having a plurality of link members that are displaced according to the rocking motion of the clutch lever 40;
a detection unit 120 that detects that the clutch lever 40 has been switched to the operating position by detecting displacement of the link mechanism 110;
includes.

With this configuration, the start of the engine 4 can be restrained according to the displacement of the link mechanism 110 interlocked with the swinging of the clutch lever 40. As a result, the degree of freedom in design can be improved, and for example, the space of each member can be saved, and the degree of freedom in arranging the detector 120 can be improved.

Further, the plurality of link members are
including the detected member 111 to be detected by the detection unit 120,
The detected member 111 is
It is displaced at a swing angle smaller than the swing angle of the clutch lever 40 .

With this configuration, the swing angle of the member to be detected 111 is kept smaller than the swing angle of the clutch lever 40, so that the movable range of the member to be detected 111 can be reduced in space. .

Further, the plurality of link members are
It further includes a connecting member 115 rotatably connected to each of the detected member 111 and the vehicle body.

With this configuration, the movable range of the member to be detected 111 is restricted by the connecting member 115, so that the displacement of the member to be detected 111 can be suppressed, and the movable range of the member to be detected 111 can be saved in space. can be planned.

Further, the member to be detected 111 is
a connected portion 112 connected to the clutch lever 40 and the connecting member 115;
a detected part 114 formed at a position displaced toward the inside of the vehicle body with respect to the connected part 112 and detected by the detection unit 120;
includes.

With this configuration, the detection unit 120 that detects the detected part 114 can be arranged inside the vehicle body, so that the detection unit 120 is prevented from interfering with obstacles (crops, trees, etc.) outside the vehicle body. can do. In addition, it is possible to suppress dust from the outside of the vehicle body from adhering to detection unit 120 .

Further, the member to be detected 111 is
In a side view, it is arranged so that at least a part thereof overlaps with the detecting portion 120 regardless of whether or not the clutch lever 40 swings.

By arranging the detection section 120 and the member to be detected 111 so as to overlap each other in a side view, the moving range of the member to be detected 111 can be reduced in space.

Further, the distance L1 from the connecting portion between the clutch lever 40 and the detected member 111 to the connecting portion between the detected member 111 and the connecting member 115 is the distance between the detected member 111 and the connecting member 115. It is formed to be longer than the distance L2 from the connecting portion to the detected portion 114 .

With this configuration, the displacement of the detected part 114 caused by the operation of the clutch lever 40 can be kept small, and the movable range of the detected member 111 can be made smaller.

In addition, a cover member 51 that covers the detection section 120 from above is further provided.

With this configuration, it is possible to suppress the adhesion of moisture and dust to the detection unit 120 .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above configurations, and various modifications are possible within the scope of the invention described in the claims.

For example, in the present embodiment, the detection portion 120 is provided on the stay 52 of the cover portion 50, and the cover member 51, which is used as a guide for the operation lever 70, etc., is also used as a cover for the detection portion 120. is not limited to a specific form. For example, a separate cover may be provided to cover the detection unit 120 from above. Moreover, in the present embodiment, the detection unit 120 is covered with a cover, but the present invention is not limited to such a configuration, and the cover may not be provided. In this case, instead of the cover, the handle body 30 may cover the detecting section 120 from above.

Also, the configuration of the link mechanism 110 according to this embodiment is an example, and the link mechanism 110 is not limited to the configuration described in this embodiment. The position, number, and shape of the link members that constitute the link mechanism 110 can be appropriately changed according to the operation of the link members.

Also, for example, in the present embodiment, the position of the clutch lever 40 is detected by detecting the displacement of the link mechanism 110 that interlocks with the clutch lever 40, but the configuration is not limited to this. For example, the position of the clutch lever 40 may be detected without using the link mechanism 110, as in the modification shown in FIG. In this case, the detector 120 is appropriately arranged at a position where the position of the clutch lever 40 can be detected.

In FIG. 12, examples of arrangement of the detection unit 120 are indicated by reference numerals 120A to 120D. A specific description will be given below.

FIG. 12 shows an example in which the detection section 120A is arranged on the upper surface of the grip section 34 of the handle body 30. As shown in FIG. According to this, the position of the clutch lever 40 can be detected by pressing the detecting portion 120A with the grasping portion 43 of the clutch lever 40 displaced to the working position.

In addition, FIG. 12 shows an example in which the detection part 120B is arranged inside the side part 31 of the handle body 30. As shown in FIG. According to this, the position of the clutch lever 40 can be detected by pressing the detecting portion 120B with the side portion 41 of the clutch lever 40 displaced to the working position.

Also, FIG. 12 shows an example in which the detection section 120C is arranged on the lower surface of the side portion 31 of the handle body 30 and in front of the clutch lever 40. As shown in FIG. According to this, the position of the clutch lever 40 can be detected by pressing the detecting portion 120C with the lower portion 42 of the side portion 41 of the clutch lever 40 displaced to the working position.

In addition, FIG. 12 shows an example in which a detecting portion 120D capable of detecting the amount of rocking of the clutch lever 40 is arranged on the rocking shaft (pin A) of the clutch lever 40. As shown in FIG. Appropriate sensors (potentiometer, etc.) can be employed as the detection unit 120D. According to this, the position of the clutch lever 40 can be detected based on the swing amount of the clutch lever 40 .

Further, for example, a detection unit (not shown) capable of detecting the operation of the wire 44 may be provided at the end of the wire 44 of the clutch lever 40 on the clutch mechanism 10 side. According to this, the position of the clutch lever 40 can be detected based on the movement of the wire 44 interlocking with the swing shaft of the clutch lever 40 .

According to the modified example described above, the position of the clutch lever 40 can be detected with a simple configuration without using a link mechanism.

Also, in this embodiment, an example in which the present invention is applied to a walk-behind tending machine having a dead man's clutch lever is shown, but the present invention is not limited to this. That is, the clutch lever 40 does not have to function as a deadman's clutch lever. In addition, it is applicable not only to a clutch lever that is held while working, but also to a lever-type clutch that does not return to its initial position when not operated. In other words, it is sufficient to prevent the engine 4 from starting when the engine 4 is started while the engine 4 is stopped and the clutch lever is switched to the operating position.

The second embodiment will be described below.

The present disclosure relates to technology of power transmission mechanisms of work machines and walk-behind management machines.

Conventionally, the technology of the power transmission mechanism of work equipment is publicly known. For example, as described in JP-A-2011-63224.

A differential lock device (power transmission mechanism) described in JP-A-2011-63224 includes a claw clutch, a fork, and the like. The pawl clutch is slidably mounted on the axle. The pawl clutch is configured to engage with a clutch engaging portion formed on the input sprocket. The fork can move the pawl clutch toward and away from the clutch engaging portion as the operating tool is operated. By bringing the pawl clutch closer to the clutch engaging portion, the fork can engage the pawl clutch and the clutch engaging portion to prohibit differential motion. Further, the fork can release the above-mentioned engagement by separating the pawl clutch from the clutch engaging portion and allow the differential.

However, in the differential lock device disclosed in Japanese Patent Application Laid-Open No. 2011-63224, depending on the relative positional relationship between the pawl clutch and the clutch engaging portion in the circumferential direction, when the pawl clutch is brought closer, the end surface of the pawl clutch may become the clutch engaging portion. There was a possibility that the fork would contact the end face and not mesh well, and an excessive load would be applied to the fork.

One aspect of the present disclosure has been made in view of the circumstances as described above. To provide a power transmission mechanism for a work machine and a walk-behind management machine.

The walk-behind management machine 201 according to the second embodiment will be described below with reference to FIG. In the following description, the forward direction (direction of arrow F in the figure) and backward direction (direction of arrow B in the figure) of the walk-behind tending machine 201 are the forward direction (the direction of the arrow F in the figure), and the left side when the operator sees the direction of motion. to the left (in the direction of arrow L in the figure), to the right when the operator looks at the direction of travel (in the direction of arrow R in the figure), to vertically upward (in the direction of arrow U in the figure), and to the vertical The downward direction (direction of arrow D in the figure) will be described.

The walking type management machine 201 includes a body frame 202, wheels 203, an engine 204, a fuel tank 205, a bonnet 206, a cover 207, a transmission case 208, a rotary tillage device 209, a clutch mechanism 210, a handle frame 211, a handle connection part 212, and a steering wheel. A handle 213 and the like are provided.

The body frame 202 is a member formed by appropriately bending a plate material. The body frame 202 is supported by a pair of left and right wheels 203 . A pair of left and right wheels 203 are configured to be differentially operated by a differential device 230, which will be described later. Engine 204 is mounted on fuselage frame 202 . Fuel tank 205 is arranged behind engine 204 . The engine 204 and fuel tank 205 are covered with a bonnet 206 . A cover 207 that covers a clutch mechanism 210 that transmits the power of the engine 204 to the transmission case 208 is provided on the side of the engine 204 .

The transmission case 208 has a rotating shaft 208a that rotates when power is transmitted from the engine 204, and a plurality of shafts and gears (see FIG. 14) that transmit power to the rotating shaft 208a and the axle 203a. The rotary tillage device 209 comprises a tillage tine 209a fixed to a rotating shaft 208a and a tillage cover 209b covering the top of the tillage tine 209a. The clutch mechanism 210 is for switching whether or not to transmit power from the engine 204 to the transmission case 208 . As the clutch mechanism 210 of the present embodiment, a so-called belt tension clutch is assumed that enables transmission of power by applying tension to a belt wound around a pulley.

A handle frame 211 is arranged above the tillage cover 209b. The handle frame 211 is a frame for supporting the steering handle 213 . The handle frame 211 is formed to extend rearward and upward. A steering handle 213 is attached to the rear upper end portion of the handle frame 211 via a handle connecting portion 212 .

The control handle 213 is for the operator to control. The steering handle 213 has an operable main clutch lever 213a and a differential lock lever 213b. The main clutch lever 213a is connected with the clutch mechanism 210 via a cable (not shown). The differential lock lever 213b is connected to a later-described slide mechanism 290 via a cable 341 (see FIG. 18) and the like.

In the walk-behind management machine 201 configured as described above, when the main clutch lever 213a of the steering handle 213 is operated, tension is applied to the belt and the clutch mechanism 210 is operated. Thereby, power from the engine 204 is transmitted to the mission case 208 . Thus, the walking type tending machine 201 can rotate the wheels 203 and the tillage tines 209a to till the field.

Also, in the walking type tending machine 201, the application of tension to the belt is stopped by releasing the operation of the main clutch lever 213a, and the operation of the clutch mechanism 210 is stopped. This stops the rotation of the wheels 203 and the tillage tines 209a.

In addition, the walking type management machine 201 can switch whether or not the pair of left and right wheels 203 can be differentially operated by operating the differential lock lever 213b.

A power transmission mechanism 240 for transmitting power from the engine 204 will be described below with reference to FIGS. 13 to 16. FIG. The power transmission mechanism 240 is provided in the transmission case 208 and can transmit the power from the engine 204 to the tillage tines 209a (rotary tillage device 209) and the wheels 203.

Power transmission from the engine 204 to the tillage tines 209a (rotary tillage device 209) will be briefly described below with reference to FIGS. 13 to 15. FIG. 14 and 15, and FIG. 16, which will be described later, show shafts, gears, and the like provided in the transmission case 208. As shown in FIG. Also, in FIGS. 14 to 16, some gears and shafts are omitted for convenience of explanation.

When engine 204 is driven, power from engine 204 is transmitted to input shaft 221 via clutch mechanism 210 . The power is transmitted to the intermediate shaft 222 via the input gear 221a and the first intermediate gear 222a shown in FIGS. 14 and 15, and the like. The power transmitted to the intermediate shaft 222 is transmitted to the PTO shaft 223 via a PTO gear 250 and the like, which will be described later, and transmitted to the rotating shaft 208a shown in FIG. 13 via a chain 223a attached to the PTO shaft 223. . In this way, power from the engine 204 is transmitted to the tillage tines 209a to rotate the tillage tines 209a.

Power transmission from the engine 204 to the wheels 203 will be briefly described below with reference to FIGS. 13, 14 and 16. FIG.

As described above, power from the engine 204 shown in FIG. 13 is transmitted from the input shaft 221 to the intermediate shaft 222. The power transmitted to intermediate shaft 222 is transmitted to transmission shaft 224 via second intermediate gear 222b and transmission gear 224a shown in FIGS. The power transmitted to the transmission shaft 224 is transmitted to the differential device 230 via a transmission chain 224b attached to the transmission shaft 224. As shown in FIG.

The differential device 230 is for enabling the differential of the wheels 203. The differential gear 230 has a differential sprocket 231 , pinion gears 232 and side gears 233 . The differential sprocket 231 is connected to the transmission shaft 224 via a transmission chain 224b. The pinion gear 232 is supported by the differential sprocket 231 and configured to be rotatable integrally with the rotation of the differential sprocket 231 and to be relatively rotatable (rotating) with respect to the differential sprocket 231 . The side gear 233 is supported by the axle 203 a and meshes with the pinion gear 232 .

The power from the engine 204 is transmitted through the transmission chain 224b to the differential sprocket 231 of the differential gear 230 configured as described above. The power is transmitted to the pair of left and right axles 203a via the pinion gear 232 and the side gear 233. As shown in FIG. In this way, the power from the engine 204 is transmitted to the pair of left and right wheels 203, and the wheels 203 can be rotated. Further, the differential device 230 causes the pinion gear 232 to rotate (rotate) with respect to the differential sprocket 231 according to the load of the wheel 203, thereby differentially moving the wheel 203 and making it easier to turn the walking type tending machine 201. be able to.

The power transmission mechanism 240 can switch between propriety of power transmission to the tillage tines 209a described above and propriety of differential operation by the differential device 230 by means of a slide mechanism 290 and the like, which will be described later. A configuration for switching whether power transmission is possible or not will be described below.

As shown in FIGS. 15 and 17, the power transmission mechanism 240 includes a PTO gear 250, a PTO shifter 260, a differential sprocket 231, a retraction mechanism 270, a differential lock shifter 280 and a slide mechanism 290. In addition, in the drawings after FIG. 17 , only the members related to switching between propriety of differential and propriety of power transmission are appropriately described.

As shown in FIGS. 19 to 21, the PTO gear 250 is formed in a substantially cylindrical shape with the axial direction oriented in the left-right direction (direction parallel to the axial direction of the PTO shaft 223). The PTO gear 250 is formed in a stepped cylindrical shape with different diameters at the left portion, the middle portion on the left and right, and the right portion. The PTO gear 250 is rotatably supported on the PTO shaft 223 . The PTO gear 250 has a facing surface 251 and claws 252 .

The facing surface 251 is a surface facing the PTO shifter 260 . The facing surface 251 is formed inside the PTO gear 250 . Also, the facing surface 251 is formed so as to face rightward.

The claw portion 252 is a portion that can be engaged with the PTO shifter 260 . As shown in FIGS. 21 and 23, the claw portion 252 is formed to protrude rightward (toward the PTO shifter 260) from the facing surface 251. As shown in FIGS. The claw portion 252 is formed in a substantially rectangular parallelepiped shape. A plurality of (three in this embodiment) claw portions 252 are formed at intervals in the circumferential direction of the PTO gear 250 .

The PTO shifter 260 shown in Figs. 20 and 22 is for switching whether or not to transmit power to the tillage tines 209a. As will be described later, the PTO shifter 260 can switch whether or not to transmit power by engaging with or disengaging from the PTO gear 250 . The PTO shifter 260 is formed in a substantially cylindrical shape with the axial direction oriented in the left-right direction. The PTO shifter 260 is formed in a stepped cylindrical shape in which the outer diameter of the left and right middle portion is smaller than the outer diameter of the left and right end portions. The PTO shifter 260 is formed so as to be able to enter the PTO gear 250 from the right side. The PTO shifter 260 has a facing surface 261 , a claw portion 262 and a stepped portion 263 . Below, the configuration of the PTO shifter 260 will be described based on the state in which the PTO gear 250 and the PTO shifter 260 are not engaged as shown in FIGS.

The facing surface 261 is a surface facing the facing surface 251 of the PTO gear 250 . Specifically, the facing surface 261 is the left side surface of the PTO shifter 260 .

The pawl portion 262 is a portion that can be engaged with the pawl portion 252 of the PTO gear 250 . As shown in FIGS. 22 and 23, the claw portion 262 is formed to protrude leftward (toward the PTO gear 250) from the facing surface 261. As shown in FIGS. The claw portion 262 is formed in a substantially rectangular parallelepiped shape. A plurality of (three in this embodiment) claw portions 262 are formed at intervals in the circumferential direction of the PTO shifter 260 . The intervals between the claw portions 262 are set to be substantially the same as the intervals between the claw portions 252 of the PTO gear 250 .

The stepped portion 263 is a portion that engages with a shift fork 350 (see FIG. 20), which will be described later. The stepped portion 263 is formed in the left-right middle portion of the PTO shifter 260 . The stepped portion 263 is formed to have a smaller outer diameter than other portions.

As shown in FIGS. 17 and 19, the PTO shifter 260 is supported on the right end of the PTO shaft 223. The PTO shifter 260 is spline-fitted to the PTO shaft 223 so as to be movable in the left-right direction relative to the PTO shaft 223 and rotatable integrally with the PTO shaft 223 . PTO shifter 260 is arranged to the right of PTO gear 250 . The facing surface 261 of the PTO shifter 260 faces the facing surface 251 of the PTO gear 250 (see FIG. 23).

The PTO shifter 260 configured as described above can switch whether or not to transmit power to the tillage tines 209a by moving in the left-right direction. Specifically, the PTO shifter 260 moves leftward from the state shown in FIGS. 17 and 19 to approach the PTO gear 250 and enter the PTO gear 250 . The pawl portion 262 of the PTO shifter 260 meshes with the pawl portion 252 of the PTO gear 250 . Specifically, the claw portion 262 of the PTO shifter 260 is arranged on one side in the circumferential direction of the claw portion 252 of the PTO gear 250 (see FIG. 31(a)).

Thus, the PTO shifter 260 abuts (engages) the pawl portion 262 of the PTO gear 250 against the pawl portion 252 of the PTO gear 250 and rotates integrally with the rotation of the PTO gear 250 . The PTO shaft 223 rotates integrally with the PTO shifter 260, and power from the engine 204 is transmitted to the tillage tines 209a via the chain 223a. Hereinafter, such a state in which power can be transmitted to the tillage tines 209a is referred to as a "power transmission state."

Further, by moving the PTO shifter 260 to the right, as shown in FIG. Thus, power transmission to the tillage tines 209a is cut off. Hereinafter, such a state in which power cannot be transmitted to the tillage tines 209a is referred to as a "power cutoff state."

As shown in FIGS. 19, 20 and 24, the differential sprocket 231 is formed in a substantially disc shape with its plate surface directed in the left-right direction. The differential sprocket 231 is supported by the axle 203a via a side gear 233, and is rotatable around the axle 203a (see FIG. 14). The differential sprocket 231 is manufactured, for example, by forging. The differential sprocket 231 has a facing surface 231a and a through hole 231b.

The facing surface 231 a is a surface facing the differential lock shifter 280 . Specifically, the facing surface 231 a is the right side surface of the differential sprocket 231 .

A through hole 231b shown in FIG. 24 is a hole penetrating the differential sprocket 231 from side to side. The through hole 231b is formed in a substantially circular shape when viewed from the side. A plurality of through holes 231 b (two in this embodiment) are provided at intervals in the circumferential direction of the differential sprocket 231 .

The advance/retreat mechanism 270 shown in FIGS. 17, 19, and 25 advances and retreats a pin 272, which will be described later. The advance/retreat mechanisms 270 are provided in the through holes 231b of the differential sprocket 231, respectively. The advancing/retreating mechanism 270 has a fixing member 271 , a pin 272 , a circlip 273 and a spring 274 .

The fixing member 271 is a substantially cylindrical member fixed to the differential sprocket 231 . The fixing member 271 is arranged with its axial direction oriented in the left-right direction. The fixing member 271 is fixed to the through hole 231b of the differential sprocket 231 by welding. The right end of the fixing member 271 is arranged so as not to protrude rightward (toward the differential lock shifter 280 ) beyond the facing surface 231 a of the differential sprocket 231 . As shown in FIG. 25(b), the fixing member 271 has a small diameter portion 271a and a large diameter portion 271b.

The small-diameter portion 271a is a portion of the inner peripheral surface of the fixing member 271 that has a smaller diameter than other portions. The small diameter portion 271 a is formed on the right portion of the fixing member 271 . The large diameter portion 271b is a portion of the inner peripheral surface of the fixing member 271 excluding the small diameter portion 271a. The large-diameter portion 271b is formed so as to extend from the left end portion of the fixing member 271 to the left-right middle portion.

The pin 272 is a substantially cylindrical member that can be engaged with the differential lock shifter 280 . The pin 272 is arranged such that its axial direction is oriented in the left-right direction, and the flange-shaped head portion 272a is oriented leftward. A head portion 272 a of the pin 272 has an outer diameter approximately equal to the inner diameter of the large diameter portion 271 b of the fixing member 271 . A shaft portion 272b of the pin 272 has an outer diameter substantially equal to the inner diameter of the small-diameter portion 271a, and is formed so as to have a larger axial width (horizontal length) than the small-diameter portion 271a.

The pin 272 configured as described above is inserted into the fixing member 271 from the left side (large diameter portion 271b side). In this way, the pin 272 has its head portion 272a disposed within the large diameter portion 271b and its shaft portion 272b inserted through the small diameter portion 271a, so that the pin 272 slides in the lateral direction (the same direction as the axial direction of the pin 272) relative to the fixed member 271. movably provided.

The circlip 273 is for stopping a spring 274, which will be described later. The circlip 273 is fixed to the large diameter portion 271b of the fixing member 271 and is spaced leftward from the pin 272 .

A spring 274 is for urging the pin 272 to the right. The right end of spring 274 contacts head 272 a of pin 272 . The left end of spring 274 abuts on circlip 273 . The spring 274 is configured by a coil spring.

The pin 272 of the advance/retreat mechanism 270 configured as described above has the head portion 272a slid to the right end of the large diameter portion 271b by the biasing force of the spring 274, and the shaft portion 272b protrudes rightward from the small diameter portion 271a. is placed in The pin 272 slides leftward on the fixing member 271 against the biasing force of the spring 274 by being pressed leftward. The pin 272 can thus move into the fixing member 271 .

The differential lock shifter 280 shown in FIGS. 17 and 19 is for switching whether the differential of the wheels 203 is enabled or disabled. As will be described later, the differential lock shifter 280 can switch whether or not the differential is enabled by engaging with or disengaging from the pin 272 of the advancing/retreating mechanism 270 . Below, the configuration of the differential lock shifter 280 will be described with reference to the state in which the differential lock shifter 280 and the pin 272 are not engaged as shown in FIGS. 17 and 19 .

As shown in FIGS. 20 and 26, the differential lock shifter 280 is formed in a substantially plate shape with its plate surface directed in the left-right direction. Differential lock shifter 280 is formed in a substantially annular shape when viewed from the side. Differential lock shifter 280 is manufactured by, for example, forging. The differential lock shifter 280 has a facing surface 281 , a peak portion 282 , a valley portion 283 and a stepped portion 284 .

The facing surface 281 is a surface facing the facing surface 231 a of the differential sprocket 231 . Specifically, the facing surface 281 is the left side surface of the differential lock shifter 280 .

The peak portion 282 is a portion that protrudes leftward (toward the differential sprocket 231 ) from the facing surface 281 . The peak portion 282 is formed at the radially outer end portion of the differential lock shifter 280 . A plurality of peaks 282 (four in this embodiment) are formed at intervals in the circumferential direction of the differential lock shifter 280 .

The trough portion 283 is a portion recessed to the right side (opposite side to the differential sprocket 231) with respect to the peak portion 282. A plurality of (four in this embodiment) valley portions 283 are formed so as to be continuous with the peak portions 282 in the circumferential direction. As shown in FIG. 27, the trough portion 283 is formed so that the circumferential width (vertical width in FIG. 27) is longer than the outer diameter of the pin 272, and the pin 272 is formed to be able to enter inside.

The stepped portion 284 is a portion that engages with the shift fork 350 (see FIG. 20). The stepped portion 284 is formed in the left-right middle portion of the PTO shifter 260 . The stepped portion 284 is formed to have a smaller outer diameter than other portions.

A pin 272 (see FIG. 20, etc.) of the differential sprocket 231 is arranged to face the outer peripheral portion of the differential lock shifter 280 . That is, the pin 272 is arranged so as to face the peak portion 282 or the valley portion 283 .

As shown in FIGS. 17 and 18, the differential lock shifter 280 is supported by the right axle 203a and arranged to the right of the differential sprocket 231. As shown in FIG. Thus, the facing surface 281 of the differential lock shifter 280 faces the facing surface 231 a of the differential sprocket 231 . Also, the valley portion 283 is arranged on the same circumference as the pin 272 (see FIG. 27). The differential lock shifter 280 is spline-fitted to the axle 203a so as to be movable in the lateral direction relative to the axle 203a and to rotate integrally with the axle 203a. Thus, differential lock shifter 280 can rotate coaxially with differential sprocket 231 . Further, as shown in FIGS. 18 and 19, the differential lock shifter 280 is arranged on the lower front left side of the PTO shifter 260 .

The differential lock shifter 280 configured as described above can switch whether or not the differential is enabled by moving in the left-right direction (direction parallel to the moving direction of the PTO shifter 260). Specifically, differential lock shifter 280 approaches differential sprocket 231 by moving leftward from the states shown in FIGS. 17, 19 and 27 . The trough portion 283 of the differential lock shifter 280 engages with the pin 272 of the advance/retreat mechanism 270 when the pin 272 is inserted therein (see FIG. 31(b)).

When the trough portion 283 and the pin 272 are thus engaged, the pin 272 becomes capable of transmitting rotational force to the differential lock shifter 280, and the differential lock shifter 280 and the differential sprocket 231 rotate together as the differential sprocket 231 rotates. As a result, the pair of left and right axles 203a rotate integrally, and the differential motion of the wheels 203 is prohibited. Hereinafter, such a state in which differential is prohibited will be referred to as a "differential prohibited state."

Further, by moving the differential lock shifter 280 to the right, the valley 283 is separated from the pin 272 as shown in FIG. Thus, the differential of the wheels 203 is allowed. Hereinafter, a state in which such a differential is permitted is referred to as a "differential permitted state."

The slide mechanism 290 is for operating the PTO shifter 260 and the differential lock shifter 280. As shown in FIGS. 17 to 20, slide mechanism 290 includes shaft 300, pin 310, receiving member 320, spring 330, connecting member 340 and shift fork 350. As shown in FIGS.

The shaft 300 supports a shift fork 350, which will be described later, so as to be movable in the left-right direction. Shaft 300 is arranged with its axial direction oriented in the left-right direction. The shaft 300 is rotatably supported by the transmission case 208 (not shown).

The pin 310 is inserted through the left and right midway portions of the shaft 300 . The pin 310 is arranged with its axial direction directed in the radial direction of the shaft 300 . One end and the other end of the pin 310 in the axial direction are formed to protrude from the outer circumference of the shaft 300 .

The receiving member 320 receives the shift fork 350 . The receiving member 320 is formed in a substantially annular shape having an outer diameter larger than the outer diameter of the shaft 300 and is fitted into a groove (not shown) formed in the shaft 300 . The receiving member 320 is arranged to the right of the pin 310 and the shift fork 350 . Thus, the receiving member 320 can restrict the rightward movement of the shift fork 350 (receive the shift fork 350).

The spring 330 biases the shift fork 350. The spring 330 is arranged on the left side of the pin 310 with the shift fork 350 therebetween, and urges the shift fork 350 rightward.

The connecting member 340 connects the shaft 300 and the differential lock lever 213b shown in FIG. The connection member 340 is formed in a substantially L shape such that the intermediate portion of the plate surface is bent. A connecting member 340 is fixed to the right end of the shaft 300 . The connection member 340 is connected to the differential lock lever 213b via a cable 341 and a spring 342 shown in FIG. 18, and is configured to be rotatable as the differential lock lever 213b is operated. In addition, the connecting member 340 can rotate the shaft 300 as it rotates.

The shift fork 350 shown in FIGS. 20, 28 and 29 is for integrally moving the PTO shifter 260 and the differential lock shifter 280. The shift fork 350 is formed in a substantially L shape when viewed from the side (see FIG. 29(b)). The shift fork 350 includes a cylindrical portion 351 , a differential connecting portion 352 , a differential engaging portion 353 , a PTO connecting portion 354 , a PTO engaging portion 355 , first ribs 356 and second ribs 357 .

The cylindrical portion 351 is a portion formed in a substantially cylindrical shape. The cylindrical portion 351 is formed so that its axial direction is oriented in the left-right direction. Cylindrical portion 351 is formed such that shaft 300 can be inserted therethrough. The cylindrical portion 351 has a notch portion 351a.

The notch portion 351a is formed by cutting the cylindrical portion 351 from the right side. One circumferential end surface of the notch 351a (the upper end surface in FIG. 29B) is formed to extend in the left-right direction. The other circumferential end surface of the cutout portion 351a (lower end surface in FIG. 29B) is formed so as to approach one end surface side (upper side) toward the left. Two cutouts 351a are formed at intervals in the circumferential direction.

The differential connection portion 352 is a portion that connects the cylindrical portion 351 and a differential engagement portion 353, which will be described later. The differential connection portion 352 is formed in a substantially plate shape. The differential connection portion 352 is formed to linearly extend forward from the cylindrical portion 351 .

The differential engagement portion 353 is a portion that can be engaged with the differential lock shifter 280 . The differential engaging portion 353 is formed so as to be continuous with the front end portion of the differential connecting portion 352 . The differential engagement portion 353 is formed in a substantially semicircular shape in a side view with the opening directed forward. The differential engagement portion 353 has a contact portion 353a.

The contact portion 353 a is a portion that contacts the differential lock shifter 280 . The contact portion 353a is formed to be thicker than other portions. A plurality of contact portions 353 a are formed at intervals in the circumferential direction of the differential engagement portion 353 . Specifically, the abutting portion 353a has two positions facing each other across the center C353 of the differential engaging portion 353 (both ends in the circumferential direction of the differential It is formed at one position spaced approximately 90 degrees apart from both ends of the engaging portion 353 . That is, a total of three contact portions 353a are formed.

The PTO connecting portion 354 is a portion that connects the cylindrical portion 351 and a PTO engaging portion 355, which will be described later. The PTO connecting portion 354 is formed in a substantially plate shape. The PTO connecting portion 354 is formed to extend upward from the cylindrical portion 351 in a side view (see FIG. 29(a)). A first bent portion 354a that bends rightward is formed at the lower portion of the PTO connection portion 354 . A second bent portion 354b that bends upward is formed on the right side of the first bent portion 354a. In this way, the PTO connecting portion 354 is formed such that the upper end is shifted to the right with respect to the lower end (see FIG. 29(b)).

The PTO engagement portion 355 is a portion that can be engaged with the PTO shifter 260 . The PTO engaging portion 355 is formed so as to be continuous with the upper end portion of the PTO connecting portion 354 . The PTO engaging portion 355 is formed in a substantially semicircular shape in a side view with the opening facing forward and upward. The PTO engaging portion 355 is formed so as not to overlap the differential engaging portion 353 in a side view (see FIG. 29(a)). More specifically, the PTO engaging portion 355 is formed behind and above the differential engaging portion 353 in a side view. The angle α formed by a line L2 connecting the center C355 of the PTO engaging portion 355 and the center C351 of the cylindrical portion 351 and a line L1 connecting the center C353 of the differential engaging portion 353 and the center C351 is It is formed so as to be 90 degrees or less. Also, the PTO engaging portion 355 is formed at a position displaced in the left-right direction with respect to the differential engaging portion 353 . More specifically, the PTO engaging portion 355 is formed such that its lateral position is shifted to the right with respect to the lateral position of the differential engaging portion 353 (see FIG. 29(b)). The PTO engagement portion 355 has a contact portion 355a.

The contact portion 355a is a portion that contacts the PTO shifter 260. The contact portion 355a is formed to be thicker than other portions. A plurality of contact portions 355 a are formed at intervals in the circumferential direction of the PTO engaging portion 355 . Specifically, the abutting portion 355a has two positions facing each other across the center C355 of the PTO engaging portion 355 (both ends of the PTO engaging portion 355 in the circumferential direction) and between the two positions (PTO It is formed at one position spaced approximately 90 degrees apart from both ends of the engaging portion 355 . That is, a total of three contact portions 355a are formed.

The first rib 356 and the second rib 357 are portions that reinforce the first bent portion 354a. A first rib 356 and a second rib 357 are formed across the cylindrical portion 351 and the PTO connection portion 354 . The second rib 357 is arranged on the right side of the first rib 356 with the PTO connection portion 354 interposed therebetween.

As shown in FIGS. 17 and 19, the cylindrical portion 351 of the shift fork 350 configured as described above is inserted through the shaft 300 and supported by the shaft 300 so as to be relatively movable in the left-right direction. The pin 310 is brought into contact with the notch portion 351 a of the cylindrical portion 351 . The differential engaging portion 353 is fitted to the stepped portion 284 of the differential lock shifter 280 . Also, the PTO engaging portion 355 is fitted to the stepped portion 263 of the PTO shifter 260 . Thus, the PTO shifter 260 and the differential lock shifter 280 are engaged with the shift fork 350 so as to be relatively rotatable with respect to the shift fork 350 and integrally movable in the left-right direction.

The operation of the slide mechanism 290 configured as described above will be described below.

The slide mechanism 290 integrally slides the PTO shifter 260 and the differential lock shifter 280 in the horizontal direction in accordance with the forward and rearward swinging operation of the differential lock lever 213b shown in FIG. 13, thereby switching the states of the PTO shifter 260 and the like. be able to. A case in which the differential lock lever 213b is swung forward will be described below as an example.

When the differential lock lever 213b is swung forward, the connection member 340 of the slide mechanism 290 shown in FIG. 18 is pulled rearward and upward, and the connection member 340 and the shaft 300 rotate clockwise in FIG. Along with this rotation, the pin 310 rotates in the same direction as the shaft 300, and presses the notch 351a (inclined portion) of the shift fork 350 shown in FIG. As a result, the rotational motion of shaft 300 is converted into linear motion of shift fork 350 , and shift fork 350 moves leftward against the biasing force of spring 330 .

As the shift fork 350 moves leftward, the PTO shifter 260 and the differential lock shifter 280 move leftward together with the shift fork 350 . This brings the PTO shifter 260 closer to the PTO gear 250 . Also, the differential lock shifter 280 is close to the differential sprocket 231 .

In this embodiment, of the PTO shifter 260 and the differential lock shifter 280, the trough portion 283 of the differential lock shifter 280 engages with the other side (the pin 272 of the advancing/retreating mechanism 270) earlier than the claw portion 262 of the PTO shifter 260. The arrangement of the PTO shifter 260 and the differential lock shifter 280, the shape of the claw portion 262, and the like are appropriately set so as to reach . Therefore, when the shift fork 350 moves to the left, the pin 272 of the advancing/retreating mechanism 270 enters the valley portion 283 of the differential lock shifter 280 as shown in FIG. Thus, differential lock shifter 280 is switched from the differential enabled state to the differential disabled state. At this time, the claw portion 262 of the PTO shifter 260 is arranged at a position spaced rightward from the claw portion 252 of the PTO gear 250 (see distance D shown in FIG. 30(a)).

When the shift fork 350 moves further to the left from the state shown in FIG. 30, the pawl portion 262 of the PTO shifter 260 reaches a position where it meshes with the pawl portion 252 of the PTO gear 250, as shown in FIG. In this way, the PTO shifter 260 is switched from the power cutoff state to the power transmission state by engaging the pawl portion 262 with the pawl portion 252 of the PTO gear 250 .

Here, as shown in FIG. 32(b), depending on the rotational positions of the differential sprocket 231 and the differential lock shifter 280, the differential lock shifter 280 may be shifted to the left in a state in which the trough portion 283 and the pin 272 are displaced from each other in the circumferential direction. may be moved to In this case, the peak portion 282 is close to the pin 272 and the peak portion 282 and the pin 272 are in contact with each other.

When the differential lock shifter 280 further moves leftward from this state, the pin 272 is pressed leftward by the peak portion 282 and moves leftward against the biasing force of the spring 274, as shown in FIG. In this way, differential lock shifter 280 can push (retreat) pin 272 to the left even when pin 272 and peak 282 are in contact with each other, and movement to the left is not restricted. No. Therefore, shift fork 350 can move differential lock shifter 280 without difficulty even if pin 272 and peak 282 face each other. As a result, it is possible to prevent an excessive load from being applied to the slide mechanism 290 that moves the differential lock shifter 280 .

33(a), the shift fork 350 engages the pawl portion 262 of the PTO shifter 260 with the pawl portion 252 of the PTO gear 250 regardless of whether the pin 272 and the valley portion 283 are engaged. position can be reached. Thereby, the shift fork 350 can switch the PTO shifter 260 to the power transmission state regardless of whether the pin 272 and the valley portion 283 are engaged.

Since the PTO gear 250 has a relatively high number of revolutions (as compared to the differential sprocket 231), even if the end faces of the claws 252 and 62 come into contact with each other, they rotate relative to the PTO shifter 260 and the end faces come into contact with each other. The contact is released, and the claw portions 252 and 62 are quickly engaged.

Also, when a rotational difference occurs between the pair of left and right wheels 203, the differential sprocket 231 and differential lock shifter 280 rotate relative to each other from the state shown in FIG. As a result, the pin 272 is released from the pressing force of the peak portion 282 , and moves rightward (toward the differential lock shifter 280 ) by the biasing force of the spring 274 . Thus, the pin 272 and the trough portion 283 are engaged with each other, and the differential lock shifter 280 is switched to the differential prohibition state (see FIG. 31(b)).

Further, when the differential lock shifter 280 that has been switched to the differential prohibition state is rotated by the power from the engine 204, the pin 272 is pressed by the inner surfaces of the peaks 282 and the valleys 283 as shown in FIG. At this time, a force along the circumferential direction of differential lock shifter 280 acts on pin 272 from the portion of contact with the inner side surface of peak portion 282 and valley portion 283 (see arrows shown in FIG. 34). In this embodiment, the arrangement of the pin 272 and the shapes of the peaks 282 and the valleys 283 are such that the center C272 of the pin 272 is positioned in the direction of the force acting on the contact portion (on the extension line of the arrow in FIG. 34). etc., are set appropriately. With such a configuration, when the peaks 282 and the valleys 283 press the pin 272, force acts toward the center C272 of the pin 272, and the load applied to the pin 272 can be reduced.

Here, the shift fork 350 moves the differential lock shifter 280 leftward by swinging the differential lock lever 213b forward to switch to the differential prohibition state, and moves the PTO shifter 260 leftward to transmit power. state can be switched. According to such a configuration, by operating one operating tool (differential lock lever 213b), for example, a state in which tilling work can be preferably performed (walking type tending machine 201 can easily move straight, tilling claws 209a can rotate) state) can be easily switched. Operability can thereby be improved.

When the differential lock lever 213b shown in FIG. 13 is swung backward, the shaft 300 and the pin 310 rotate in the opposite direction (counterclockwise direction in FIG. 18) to the direction when the differential lock lever 213b is swung forward. . In this case, shift fork 350 shown in FIGS. 17 and 19 is biased by spring 330 to move rightward.

The PTO shifter 260 and the differential lock shifter 280 integrally move rightward as the shift fork 350 moves rightward. PTO shifter 260 and differential lock shifter 280 are thus separated from PTO gear 250 and differential sprocket 231 .

In this manner, the shift fork 350 moves the differential lock shifter 280 to the right by swinging the differential lock lever 213b rearward to switch to the differential permission state, and moves the PTO shifter 260 to the right to shift the power supply. It can be switched to the blocking state. According to such a configuration, by operating one operation tool (differential lock lever 213b), for example, normal traveling and turning can be preferably performed (walking type tending machine 201 can easily turn, tillage tines 209a can turn). can be easily switched to an immobile state). Operability can thereby be improved.

Also, the states of the PTO shifter 260 and the differential lock shifter 280 can be collectively changed with one part (shift fork 350), and the number of parts can be reduced to save space.

As described above, the power transmission mechanism 240 of the walk-behind tending machine 201 (working machine) according to the present embodiment is formed with the differential sprocket 231 (first rotating member) and the recessed valley portion 283 (engaged portion). The differential lock shifter 280 (second rotating member) and the differential lock shifter 280 (the first rotating member or the second rotating member) are arranged in a direction in which the differential sprocket 231 and the differential lock shifter 280 approach or separate from each other (horizontal direction ), and the differential sprocket 231 is provided so as to be able to move forward and backward toward the differential lock shifter 280, and engages with the valley portion 283 to move the differential. A pin 272 (engagement member) that allows the sprocket 231 and the differential lock shifter 280 to rotate integrally, and a spring 274 (biasing member) that biases the pin 272 toward the differential lock shifter 280. It is equipped.

With this configuration, when the differential sprocket 231 and the differential lock shifter 280 are moved toward each other, even if the pin 272 and the trough 283 are in a positional relationship that does not engage (cannot be engaged), the pin 272 moves backward, the relative movement between the differential sprocket 231 and the differential lock shifter 280 is not disturbed. This can prevent an excessive load from being applied to the slide mechanism 290 .

The differential sprocket 231 is rotatable on the same axis as the rotary shaft (axle 203a) of the differential lock shifter 280, and the pin 272 is movable forward and backward in a direction parallel to the rotary shaft (horizontal direction). .

With this configuration, in the power transmission mechanism 240 having the differential sprocket 231 and the differential lock shifter 280 rotating on the same axis, it is possible to prevent an excessive load from being applied to the slide mechanism 290.

In addition, the pin 272 is formed in a columnar shape with its axis directed in the advancing and retreating direction (horizontal direction).

By configuring in this way, the configuration can be simplified.

Further, the differential sprocket 231 (either the first rotating member or the second rotating member) is provided in a differential device 230 that enables differential movement of the wheels 203, and the slide mechanism 290 is the differential lock. A differential prohibition state in which the shifter 280 is moved in one direction (leftward) to engage the pin 272 with the valley portion 283 to prohibit the differential of the wheels 203 by the differential device 230, and the differential lock. A differential allowable state in which the shifter 280 is disengaged from the pin 272 and the valley portion 283 by moving the shifter 280 in the other direction (rightward) to allow the differential of the wheels 203 by the differential device 230. , can be switched.

With this configuration, it is possible to prevent an excessive load from being applied to the slide mechanism 290 when operating the differential device 230 (when switching between the differential prohibited state and the differential permitted state).

In addition, the power transmission mechanism 240 moves in a predetermined direction (horizontal direction) to switch between a power transmission state in which power can be transmitted to the rotary tillage device 209 (working device) and a power transmission state in which power can be transmitted to the rotary tillage device 209. It further comprises a PTO shifter 260 (working power switching member) capable of switching between a disabled power cutoff state and a working power switching member, and the slide mechanism 290 integrally moves the differential lock shifter 280 and the PTO shifter 260. is.

By sharing the mechanism (slide mechanism 290) for moving the differential lock shifter 280 and the PTO shifter 260 in this way, it is possible to reduce the number of parts and save space.

Further, the slide mechanism 290 moves the differential lock shifter 280 and the PTO shifter 260 in the one direction (left direction), thereby switching the differential lock shifter 280 to the differential prohibition state and the PTO shifter 260. It is possible to switch to the power transmission state, and by moving the differential lock shifter 280 and the PTO shifter 260 in the other direction (right direction), the differential lock shifter 280 is switched to the differential allowable state and the It is possible to switch the PTO shifter 260 to the power cutoff state.

By interlocking the differential device 230 and the rotary tillage device 209 in this manner, operability can be improved.

Further, when the slide mechanism 290 moves the differential lock shifter 280 and the PTO shifter 260 in the one direction (leftward direction), the slide mechanism 290 moves the pin 272 before switching the PTO shifter 260 to the power transmission state. can be engaged with the valley 283 (see FIG. 30).

With this configuration, even in a state in which the PTO shifter 260 cannot be switched to the power transmission state (a state in which the end surfaces of the claw portions 252 and 62 are in contact with each other), the differential allowable state is changed to the differential prohibition state. can be stably switched to

Also, the walk-behind management machine 201 according to the present embodiment is equipped with the power transmission mechanism 240 .

With this configuration, it is possible to prevent excessive load from being applied to the slide mechanism 290.

Note that the walk-behind management machine 201 according to the present embodiment is an embodiment of a work machine.
Further, the differential sprocket 231 according to this embodiment is one embodiment of the first rotating member.
Further, the trough portion 283 according to the present embodiment is an embodiment of the engaged portion.
Further, the differential lock shifter 280 according to this embodiment is an embodiment of the second rotating member.
Further, the slide mechanism 290 according to this embodiment is one embodiment of the moving mechanism.
Also, the pin 272 according to this embodiment is an embodiment of the engaging member.
Also, the spring 274 according to this embodiment is an embodiment of the biasing member.
Also, the rotary tillage device 209 according to the present embodiment is an embodiment of a working device.
Also, the PTO shifter 260 according to this embodiment is an embodiment of the working power switching member.

For example, the work machine was the walk-behind management machine 201, but the type of work machine is not limited to this, and may be a harvester, a lawn mower, or the like.

When the shift fork 350 is moved leftward, the PTO shifter 260 is switched to the power transmission state, and the differential lock shifter 280 is switched to the differential prohibiting state. Although the differential lock shifter 280 is switched to the differential allowable state, the relationship between the moving direction of the shift fork 350 and the switching between the power transmission state, the power cutoff state, the differential prohibition state and the differential allowable state is particularly limited. not a thing

Further, the valley portion 283 of the differential lock shifter 280 engaged with the pin 272 of the advancing/retreating mechanism 270 before the pawl portion 262 of the PTO shifter 260 engaged with the PTO gear 250 (see FIG. 30). 272 is not particularly limited. For example, valley 283 may engage pin 272 at the same time that PTO shifter 260 engages PTO gear 250 .

Also, the positional relationship between the differential engagement portion 353 and the PTO engagement portion 355 of the shift fork 350 is not particularly limited. That is, the differential engagement portion 353 is formed so as not to overlap with the PTO engagement portion 355 in a side view (see FIG. 29(a)). It can be arbitrarily changed according to the arrangement of H.260. Further, the differential engagement portion 353 is formed at a position displaced in the left-right direction with respect to the PTO engagement portion 355 (see FIG. 29(b)). It can be arbitrarily changed according to the arrangement or the like.

Further, the angle α between the straight line L1 connecting the differential engagement portion 353 and the cylindrical portion 351 and the straight line L2 connecting the PTO engaging portion 355 and the cylindrical portion 351 is formed to be 90 degrees or less in a side view. (see FIG. 29(a)), but the angle is not limited to this and can be any angle.

Also, the shift fork 350 does not necessarily have the first rib 356 and the second rib 357 .

Further, in this embodiment, the differential sprocket 231 and the differential lock shifter 280 are illustrated as examples of the first rotating member and the second rotating member according to the present invention, but the present invention is not limited to this, and various rotatable members can be applied to Further, in the present embodiment, an example is shown in which the second rotating member (differential lock shifter 280) is moved toward or away from the first rotating member (differential sprocket 231), but the present invention is not limited to this. , the first rotary member, or both the first rotary member and the second rotary member.

Also, in this embodiment, the pin 272 that is moved in the rotation axis direction (horizontal direction) of the differential sprocket 231 is illustrated as an example of the engaging member, but the configuration of the engaging member is not limited to this. The moving direction of the engaging member can be arbitrarily changed as long as it advances and retreats toward the second rotating member in which the valley portion 283 (engaged portion) is formed. For example, the pin 272 may be arranged so as to advance and retreat in the radial direction, and configured to engage with the valley portion 283 (engaged portion) arranged radially outside or inside.

In the present embodiment, the differential lock shifter 280 is provided with the valley portion 283, and the differential sprocket 231 is provided with the pin 272. However, the member provided with the pin 272 and the valley portion 283 is limited to this. not a thing That is, the pin 272 and the valley portion 283 may be provided on two different rotating members.

Also, although the pin 272 is biased by a coil spring (spring 274), the biasing member for biasing the pin 272 is not limited to the coil spring, and other types of springs, resins, or the like may be used. may be an elastic body.

In addition, two pins 272 (advance/retreat mechanism 270) are provided, but the number of pins 272 is not particularly limited, and can be arbitrarily changed according to the shape of differential sprocket 231 and the like.

Also, although the pin 272 is formed in a substantially columnar shape, the shape of the pin 272 is not particularly limited and can be arbitrarily changed. FIG. 35 shows a modification of the pin 272 in which the shape of the pin 272 is changed. A pin 272 in FIG. 35 is formed in a substantially rectangular parallelepiped shape. The pin 272 has a flat portion 272c along the inner surface of the valley portion 283. As shown in FIG. The pin 272 is engaged with the valley portion 283 by contacting the inner side surface of the valley portion 283 with the flat portion 272c. With such a configuration, the pin 272 can increase the contact area (surface contact) with the valley portion 283 .

In addition, four valleys 283 are formed in differential lock shifter 280, but the number of valleys 283 is not particularly limited, and can be arbitrarily set according to the shape of differential lock shifter 280 and the like. be.

Also, the differential sprocket 231 and the differential lock shifter 280 are manufactured by, for example, forging, but may be processed and manufactured by, for example, a lathe or a milling machine, and the manufacturing method is not limited.

The present invention can be applied to walking type management machines.

1 walk-behind management machine 40 clutch lever 100 start check mechanism 201 walk-behind management machine (working machine)
231 differential sprocket (first rotating member)
240 power transmission mechanism 272 pin (engagement member)
274 spring (biasing member)
280 differential lock shifter (second rotating member)
283 trough (engaged portion)
290 slide mechanism (moving mechanism)

Claims

The clutch mechanism is capable of swinging between an initial position and an operating position, and when switched to the operating position, the clutch mechanism is switched to a state in which power can be transmitted. a clutch lever that switches to a non-transmissible state;
a start restraint mechanism that restrains the start of the engine when it is detected that the clutch lever has been switched to the operating position;
A walk-behind management machine.
The start restraint mechanism is
a link mechanism comprising a plurality of link members that are displaced according to the swing of the clutch lever;
a detection unit that detects that the clutch lever has been switched to the operating position by detecting displacement of the link mechanism;
including,
The walking type management machine according to claim 1.
The plurality of link members are
including a detected member to be detected by the detection unit;
The member to be detected is
displaced at a small swing angle compared to the swing angle of the clutch lever;
The walking type management machine according to claim 2.
The plurality of link members are
further comprising a connecting member rotatably connected to each of the member to be detected and the vehicle body;
The walking type management machine according to claim 3.
The member to be detected is
a connected portion connected to the clutch lever and the connecting member;
a detected part formed at a position displaced toward the inside of the vehicle body with respect to the connected part and detected by the detection unit;
including,
The walk-behind management machine according to claim 4.
The member to be detected is
In a side view, regardless of whether or not the clutch lever swings, at least a portion of the clutch lever overlaps the detection unit.
The walking type management machine according to claim 5.
The distance from the connecting portion between the clutch lever and the detected member to the connecting portion between the detected member and the connecting member is from the connecting portion between the detected member and the connecting member to the detected portion. is formed to be longer than the distance of
The walking type management machine according to claim 5 or 6.
Further comprising a cover member that covers the detection unit from above,
The walking type management machine according to any one of claims 2 to 7.