JP2011115067A - Walking type implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a walking type implement capable of suppressing core shift even if a large plowing load arises at the engagement of a side clutch installed between a wheel shaft for linking a plowing shaft and a driving part. <P>SOLUTION: This walking type implement is provided by including the driving part 29, a first inner projecting part 35 at one side of the wheel shaft and a second projecting part 39 at the other side at the position of a first radius R1 from the rotary center of the wheel shaft, including the driving part 29, a first outer projecting part 36 at the one side of the wheel shaft and a second outer projecting part 40 at the other side at the position of a second radius R2 which is larger than the first radius R1, from the rotary center of the wheel shaft, constituting the side clutch so that the first inner projecting part 35 with the second inner projecting part 39, and the first outer projecting part 36 with the second outer projecting part 40 engage, and setting the first radius R1 and second radius R2 so that the first inner projecting part 35 with the second outer projecting part 40 approach or make a contact and the second inner projecting part 39 with the first outer projecting part 36 approach or make a contact. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the present invention, a drive unit that transmits power to an axle that connects a tillage shaft provided with tillage claws to the left and right and the axle are arranged concentrically, and a drive state and a non-drive state are provided between the drive unit and the axle. The present invention relates to a walking-type working machine provided with a side clutch that is fully engaged.

  In a conventional walking type work machine, as shown in Patent Document 1, a sprocket as a drive unit that transmits power to left and right axles connected to a tillage shaft provided with tillage claws and the axle are concentric. The side clutch is arranged between the sprocket and the axle so as to enter and leave the drive state and the non-drive state, and the side clutch is formed by a dog clutch in which the concave portion and the convex portion engage with each other, and the fixed clutch pawl of the dog clutch is formed. On the same circumference (same radius), two convex parts with different circumferential lengths are formed on the same circumference (same radius) as the convex part on the drive part side and the convex part forming the movable clutch pawl. Is known.

  In the thing of patent document 1, since the circumference of the 2 convex part which forms a clutch nail | claw was varied, it was made for a dog clutch to mesh | engage only one place with respect to one axle rotation, Therefore Phases of the left and right tiller shafts that are equipped with tillage claws can be driven at the same time after turning the side clutch and turning the side clutch. There is no slippage. That is, the rotation phase between the tilling claw attached to the left tilling shaft and the right tilling shaft constituting the left and right tilling rotors does not change depending on whether the dock clutch is turned on or off. As a result, even if the side clutch is turned on and off, there is no change in the mounting phase of the left and right tillage claws (left-right deviation), so the body does not swing from side to side due to a deviation in the mounting phase of the left and right tilling claws. There is an advantage that stable and good work can be performed.

Japanese Utility Model Publication No. 6-24403

  However, in the side clutch described in Patent Document 1, a fixed clutch pawl on the sprocket side and a movable clutch pawl that slides and meshes with the fixed clutch pawl in the axial direction on a single same circumference. Since the projections forming the fixed clutch pawl and the projections forming the movable clutch pawl are open in the radial direction because they are meshed with each other, misalignment (with the center of rotation of the fixed clutch pawl) (Phenomenon in which the rotational center of the movable clutch pawl is displaced in the radial direction), which causes wear and breakage of the fixed clutch pawl and the movable clutch pawl.

  To alleviate the above inconvenience, the processing accuracy of the spline that moves the movable clutch pawl in the axial direction may be increased, or the length of the boss of the movable clutch may be increased. There is a limit, and the walking type small working machine cannot make the width of the mission case arranged at the left and right center part wide.

  In the present invention, a side clutch is provided on an axle that connects a tilling shaft with left and right tilling claws, and a large load is applied during the operation in which the fixed clutch pawl on the drive unit side and the movable clutch pawl on the axle side are engaged. It is an object of the present invention to provide a walking type work machine capable of stabilizing the meshing by suppressing the occurrence of misalignment between the fixed clutch pawl and the movable clutch pawl even if it is applied.

[Configuration of the first invention]
1st invention arrange | positions the drive part which transmits motive power to the axle shaft which connects the tilling shaft provided with the tilling claw on the right and left, and the said axle shaft, and a drive state and non-drive between the said drive part and an axle shaft Provide a side clutch that enters and exits the state,
A first inner recess is provided on one of the drive unit and the axle at a position of a first radius from the rotation center of the axle, and the first inner projection is circumferentially adjacent to the first inner recess. A second inner convex portion and a second inner concave portion that engage with the first inner concave portion and the first inner convex portion, respectively, on the other side of the axle;
A first outer concave portion and a first outer convex portion adjacent to the first outer concave portion at one of the driving portion and the axle at a position of a second radius larger than the first radius from the rotation center of the axle; A second outer convex portion and a second outer concave portion that are engaged with the first outer concave portion and the first outer convex portion, respectively, on the other of the portion and the axle,
The first inner convex portion and the first outer convex portion engage with the second inner concave portion and the second outer concave portion, respectively, and the second inner convex portion and the second outer convex portion are the first inner concave portion and the second outer concave portion, respectively. By engaging the first outer concave portion, the first inner convex portion and the second inner convex portion are engaged with each other, and the first outer convex portion and the second outer convex portion are engaged with each other. Configure
The outer peripheral surface of the first inner convex portion and the inner peripheral surface of the second outer convex portion are close to or abut, and the outer peripheral surface of the second inner convex portion and the inner peripheral surface of the first outer convex portion are close or Set the first radius and the second radius so that they touch each other,
The phase of the first inner convex portion and the second inner convex portion, or the phase of the first outer convex portion and the second outer convex portion so that the side clutch is engaged only in one phase in the rotational direction. Is set.

[Operation of the first invention]
According to the first invention, the inner convex portion on the drive portion side is the first inner convex portion, the outer convex portion is the first outer convex portion, the inner convex portion on the axle side is the second inner convex portion, and the outer convex portion. When the portion is the second outer convex portion, the inner peripheral surface of the first outer convex portion on the drive portion side even if a sudden tillage load is applied and misalignment occurs between the drive portion side and the axle side The outer peripheral surface of the second inner convex portion on the axle side contacts the outer peripheral surface of the first inner convex portion on the drive portion side, and the inner peripheral surface of the second outer convex portion on the axle side contacts the outer peripheral surface of the drive portion. The radial misalignment on the side and the axle side is suppressed.

[Effect of the first invention]
As described above, according to the first aspect of the present invention, the radial misalignment on the drive unit side and the axle side is suppressed, so that the engagement of the side clutch is stabilized, and the wear and loss of the clutch pawl is suppressed for a long time. Stable meshing can be obtained.

[Configuration of the second invention]
According to a second invention, in the configuration of the first invention, the first inner concave portion and the first outer concave portion are formed at a phase difference of 180 degrees, and the second inner convex portion and the second outer convex portion Is formed at a phase difference position of 180 degrees.

[Operation and effect of the second invention]
For example, if the inner and outer protrusions (inner and outer recesses) of the side clutch are provided at the same phase position, the entire clutch is the same as the clutch that engages only at one place on the circumference, and the clutch is engaged. Although the engagement force is lacking, according to the second invention, for example, as shown in FIG. 8, since the two engagement portions are provided with a phase difference close to 180 degrees, a stable connection (entering) state with a large engagement force is provided. The resulting side clutch can be provided.

[Configuration of the third invention]
According to a third invention, in the configuration of the first invention or the second invention, the side clutch includes a right side clutch that can be transmitted to and disconnected from the right axle, and a left side clutch that can be transmitted to and disconnected from the left axle. It is.

[Operation and effect of the third invention]
In a walk-type work machine such as a small walk-type management machine having a tillage claw attached to a tillage shaft connected to an axle, it can be turned without a side clutch. Further, even if the side clutch for turning is provided only on one of the right and left sides, the turning direction is always the same, but turning is facilitated. On the other hand, when side clutches are provided on the left and right as in the third aspect of the invention, a small turn can be made in either the left or right direction, and work efficiency is improved.

[Configuration of the fourth invention]
According to a fourth aspect of the present invention, in the configuration of the third aspect, the left and right side clutches are linked to the right clutch operating tool and the left clutch operating tool separately for each of the left and right, and can be separated into the left and right.

[Effects of the fourth invention]
If the left and right side clutches are linked to a single clutch operating tool, the left and right clutches cannot be disengaged at the same time. However, as in the fourth aspect, the left and right clutch operating tools are linked to the left and right side clutches respectively. If connected, only the other clutch operating tool is intermittently turned on and off with one side clutch engaged, the other clutch operating tool is intermittently turned on and off with one side clutch disconnected, By alternately turning the clutch operating tool on and off, it is possible to turn at a desired turning speed and turning radius, and to freely turn according to the work width.

It is the whole walk type work machine side view. It is a longitudinal front view of a mission case. It is a vertical side view of a mission case. It is a top view of a planetary reduction mechanism. It is a vertical side view of the principal part which shows the on / off state of a clutch mechanism. It is a cross-sectional plan view of a side clutch. It is a perspective view of the fixed clutch pawl on the bevel gear side of the side clutch and the movable clutch pawl on the holder side. It is a front view of the fixed clutch pawl on the bevel gear side of the side clutch and the movable clutch pawl on the holder side. It is a cross-sectional top view of the side clutch of another embodiment. It is a vertical side view of the mission case of another embodiment. It is a front view of the fixed clutch claw on the bevel gear side and the movable clutch claw on the holder side of the side clutch of another embodiment. It is a cross-sectional top view of the side clutch which shows a comparative example. It is a perspective view of the fixed clutch pawl on the bevel gear side of the side clutch and the movable clutch pawl on the holder side showing a comparative example. It is a front view of a fixed clutch pawl on the bevel gear side and a movable clutch pawl on the holder side of a side clutch showing a comparative example.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that “front”, “rear”, “left”, “right”, “upper”, and “lower” follow the directions as viewed from the operator having the steering handle 8 of the walking work machine. The drawings are to be viewed in the direction of the reference numerals.

  FIG. 1 is a side view showing a walking type working machine according to the present invention. The walking type work machine transmits the power of the engine 1 as a drive source to the left and right axles 3 via the mission case 2 so that the tilling work is performed by the tilling rotor 4 as a working unit attached to the axle 3. At the same time, it is a self-propelled walking type working machine that is driven by the tilling rotor 4.

  The tilling rotor 4 includes a tilling shaft 5 connected to the left and right axles 3 and a plurality of tilling claws 7 that are detachably attached via a pawl attaching portion 6 fixed to the outer periphery of the tilling shaft 5. .

  The engine 1 is provided in the upper part of the mission case 2, a handle frame 9 for attaching the steering handle 8 to the rear is extended from the mission case 2, the hitch 10 is connected to the handle frame 9, and the resistance bar 11 is adjusted to the height of the hitch 10. It is attached as possible.

  As shown in FIG. 2, the transmission case 2 includes a planetary reduction device 12 that uses the output shaft 1a of the engine 1 as a sun gear, a longitudinal transmission shaft 13 that is disposed on the same axis P1 as the output shaft 1a, and The bevel gear type transmission mechanism 14 attached to the lower end of the vertical transmission shaft 13 is internally provided. At the lower part of the mission case 2, lateral left and right axles 3 projecting from the mission case 2 toward the left and right outer sides are disposed, and a tilling shaft 5 having tilling claws 7 on the left and right of the axle 3. Are connected so as to rotate together.

  As shown in FIGS. 2 to 4, the planetary reduction device 12 includes a sun gear 1 b formed on the output shaft 1 a, three planet gears 16 that mesh with the sun gear 1 b, and planets that support these planet gears 16 at equal intervals. The carrier 17 and the ring gear 18 that meshes and guides these planetary gears 16 and the like. The rotation of the output shaft 1a causes each planetary gear 16 to revolve to the planetary carrier 17 while revolving, The planet carrier 17 is driven to rotate at a reduced speed around the same axis P1 as the output shaft 1a.

  As shown in FIGS. 3 and 5, the clutch mechanism 19 includes a planetary carrier 17 of the planetary reduction device 12, a cylindrical shaft 20 that rotates integrally with the transmission shaft 13, a recess 20 a formed on the outer periphery of the cylindrical shaft 20, Six transmission balls 21 movable to through holes 17a formed in the planetary carrier 17 on the periphery, a transmission position engaged with the recess 20a, and a non-transmission position separated from the recess 20a, and transmission of these transmission balls 21 A holding position that is held in position, a slidable holder 22 that allows the transmission ball 21 to move to a non-transmission position, and a spring 23 that urges the holder 22 back to the non-holding position are configured. . The clutch mechanism 19 is in a state in which the transmission shaft 13 is not driven by the sliding operation of the holder 22 by a single shift fork 24 (see FIG. 5 (A)) and in a state in which the transmission shaft 13 is driven (see FIG. 5 (B)). Are arranged in a dead space S below the planetary reduction gear 12.

  As shown in FIGS. 1 and 3, the shift fork 24 is rotatable around a horizontal axis P <b> 2 orthogonal to the vertical transmission shaft 13 in the dead space S below the planetary reduction gear 12 in the mission case 2. The operation shaft 25 is fixedly disposed. An operation arm 26 is connected to the outer end of the operation shaft 25 so as to rotate integrally around the horizontal axis P2. The operation arm 26 is linked to an operation lever 27 mounted on the steering handle 8 via a wire (not shown).

  From this configuration, when the operation lever 27 is gripped to the steering handle 8 side, the operation arm 26 rotates to push up the holder 22 via the shift fork 24 (see FIG. 5B), and from the engine 1 via the planetary gear 16. Thus, the power transmitted to the planet carrier 17 is transmitted to the transmission shaft 13, whereby transmission from the engine 1 to the axle 3 is performed. When the operation lever 27 is released from the steering handle 8 side, the holder 22 is pushed down by the bias of the spring 23 provided in the clutch mechanism 19 (see FIG. 5 (a)), and the planetary carrier 17 rotates centrifugally. Due to the force, the transmission ball 21 is detached from the cylindrical shaft recess 20a. As a result, transmission from the engine 1 to the axle 3 is cut off.

  The axle 3 comprises axles 3a and 3b divided into left and right, and a small-diameter shaft 28 is fitted into the small-diameter shaft 28 so as to be rotatable over the left and right axles 3a and 3b. It is. The bevel gear type transmission mechanism 14 that is transmitted from the longitudinal transmission shaft 13 to the axle 3 includes a small-diameter bevel gear 30 formed at the lower end of the longitudinal transmission shaft 13 and a large-diameter bevel gear 29 that is externally fitted to the small-diameter shaft 28. Right and left side clutches 15 and 15 are provided between the large-diameter bevel gear 29 and the left and right axles 3a and 3b.

  The side clutch 15 is movable along the left and right axles 3a and 3b, and a fixed clutch pawl composed of a first inner convex portion 35 and a first outer convex portion 36 that are formed to project from the left and right side surfaces of the large-diameter bevel gear 29. A dog clutch that engages and disengages a movable clutch pawl composed of a second inner convex portion 39 and a second outer convex portion 40 protruding from the clutch disk 33 of the holder 32 that is spline-fitted. It consists of

  As shown in FIGS. 6 to 8, two first inner convex portions 35 and first outer convex portions 36 having different diameters are formed on the left and right side surfaces of the large-diameter bevel gear 29. The first inner convex portion 35 and the first outer convex portion 36 are configured over a wide range exceeding approximately 300 degrees or more than 300 degrees in the circumferential direction with a phase difference of 180 degrees or approximately 180 degrees, respectively. A first inner protrusion 35 is provided at a position of a first radius R1 having a short radius from the rotation center of the axle 3, and a first outer protrusion is formed at a position of a second radius R2 larger than the first radius R1 from the rotation center of the axle 3. A portion 36 is provided. A first inner concave portion 37 is formed in a notch portion of the first inner convex portion 35, and a first outer concave portion 38 is formed in a notch portion of the first outer convex portion 36. Thereby, the 1st inner crevice 37 and the 1st outer crevice 38 are arranged in the position of a phase difference of about 180 degrees. That is, the second inner convex portion 39 and the second outer convex portion 40 on the holder 32 side, and the first inner concave portion 37 and the first outer concave portion 38 on the large-diameter bevel gear 29 side are present at a phase difference position of 180 degrees. It is configured.

The holder 32 has a small-diameter side (holder) that engages with notches (the first inner concave portion 37 and the first outer concave portion 38) of the first inner convex portion 35 and the first outer convex portion 36 formed in the large-diameter bevel gear 29. The second inner convex portion 39 located at the first radius R1 position from the rotation center of 32 and the second outer convex portion 40 located on the large diameter side (position of the second radius R2 from the rotation center of the holder 32). A movable clutch pawl is provided. A portion excluding the second inner convex portion 39 in the circumferential portion of the plane of the clutch disc 33 having the first radius R1 is formed as a second inner concave portion 41, and the second radius R2 of the plane of the clutch disc 33 is A portion excluding the second outer convex portion 40 in the circumferential portion is formed as a second outer concave portion 42.
As a result, the second inner convex portion 39 is fitted into the cutout portion forming the first inner concave portion 37 (and the first inner convex portion 35 is fitted into the second inner concave portion 41), and the second outer convex portion 40 is The first outer convex portion 35 and the first outer convex portion 36 on the large-diameter bevel gear 29 side are fitted into the notches forming the first outer concave portion 38 (and the first outer convex portion 36 is in the second outer concave portion 42). And the second inner convex part 39 and the second outer convex part 40 on the holder 32 side mesh with each other, the side clutch 15 enters the engaged state.

  That is, the side clutch 15 includes the first inner convex portion 35 on the large-diameter bevel gear 29 side and the second inner concave portion 41 on the holder 32 side, and the first inner concave portion 37 on the large-diameter bevel gear 29 side and the second inner concave portion on the holder 32 side. The first outer convex portion 36 on the large-diameter bevel gear 29 side and the second outer concave portion 42 on the holder 32 side, and the first outer concave portion 38 on the large-diameter bevel gear 29 side and the first on the holder 32 side are engaged with the convex portion 39. As the 2 outer convex portions 40 are engaged, the first inner convex portion 35 and the second inner convex portion 39 are engaged, and the first outer convex portion 36 and the second outer convex portion 40 are engaged. It is configured. The outer peripheral surface of the first inner convex portion 35 on the large-diameter bevel gear 29 side, the inner peripheral surface of the second outer convex portion 40 on the holder 32 side, the outer peripheral surface of the second inner convex portion 39 on the holder 32 side, and the large-diameter bevel gear. The first radius R1 and the second radius R2 are set so that the inner peripheral surface of the first outer convex portion 36 on the 29th side approaches or touches (the first inner convex in the drawings (FIGS. 6 to 8)). The gap between the portion 35 and the first outer convex portion 36, the gap between the first inner convex portion 35 and the second outer convex portion 40 in the clutch engagement state, and the first outer convex portion 36 and the second inner convex portion. The gap with the portion 39 is drawn so as to be wide, but the gap width is extremely small in practice). The side clutch 15 is engaged only at one phase position in the rotation direction (once per rotation). The meshing phase position of the first inner convex portion 35 and the second inner convex portion 39 and the meshing phase position of the first outer convex portion 36 and the second outer convex portion 40 are set to a phase difference of 180 degrees or approximately 180 degrees. It is.

  As a result, even when a large load is suddenly applied to the tilling pawl 7 when the clutch is engaged, the fixed clutch pawl (the first inner convex portion 35 and the first outer convex portion 36) and the movable clutch pawl (the second inner convex portion). Even if misalignment occurs between the portion 39 and the second outer convex portion 40), the outer peripheral surface of the second inner convex portion 39 on the axle side is on the inner peripheral surface of the first outer convex portion 36 on the drive portion side. The inner peripheral surface of the second outer convex portion 40 on the axle side is in contact with the outer peripheral surface of the first inner convex portion 35 on the drive portion side, and the movable portion side with respect to the large-diameter bevel gear 29 on the drive portion side. The holder 32 is prevented from moving outward in the radial direction.

  Further, when the clutch is engaged and operated from the clutch disengaged state, the convex portions (second inner convex portion 39 and second outer convex portion 40) of the holder 32 are recessed only once per rotation (first inner concave portion 37 and second outer convex portion 40). 1) only the outer concave portion 38) is engaged, so that even if the projecting dimensions of the plurality of convex portions 35, 36, 39, 40 are different due to manufacturing errors, the predetermined convex portions 39, 40 are always in the predetermined state when the dog clutch is engaged. Since the concave portions 37 and 38 are engaged with each other, there is no inconvenience that the convex portion 39 contacts the corner portion of the other concave portion 38.

  As shown in FIGS. 2, 3, and 6, the spring that presses the holder 32 between the holder 32 of the left and right side clutches 15, 15 and the stopper 43 on the outer side thereof and biases the side clutch 15 inward. 44 is interposed. An engaging portion 47 made of an engaging pin provided at the tip of a shift fork 46 for operating the holder 32 to the clutch disengagement side is fitted into the circumferential groove 45 formed in the holder 32. The left and right holders 32 are independently operated on the left and right by right or left shift forks 46 provided separately for the left and right. When the shift fork 46 is returned to its original position, the urging force of the spring 44 causes the holder 32 to return to the clutch engagement side so as to be transmitted to the left and right axles 3a and 3b, and is thus mounted on the left and right axles 3a and 3b. The straight running state by the thrust of each tilled rotor 4 can be revealed.

As shown in FIGS. 3 and 6, the shift fork 46 is rotatable around the longitudinal axis P <b> 3 in parallel with the longitudinal transmission shaft 13 at two positions on the left and right sides of the transmission shaft 13 in the transmission case 2. Are fixed to the lower part of the operation shafts 48, 48. A fan-shaped bevel gear 49 is connected to the upper end of the operation shaft 48 so as to rotate integrally around the vertical axis P3. The bevel gear 49 meshes with a fan-shaped bevel gear 51 that rotates together with a linkage shaft 50 that is supported by the transmission case 2 so as to be rotatable around the tilt axis P4. A linkage arm 52 is fixed to the outer end of the linkage shaft 50. The shift fork 46, the engaging portion 47, the operation shaft 48, the bevel gear 49, the linkage shaft 50, the bevel gear 51, and the linkage arm 52 shown in FIG. 3 indicate the operation system A1 of the left side clutch 15, and the linkage arm 52 is A left steering lever 53 as a clutch operating tool mounted on the left steering handle 8 is linked via a linkage member 54 made of a wire.
The operation system A1 for operating the right side clutch 15 is provided symmetrically like the operation system for the left side clutch 15.

  From this configuration, when the left steering lever 53 (clutch operating tool) is gripped during the operation, the left wire 54, the left linkage arm 52, the left linkage shaft 50, the left bevel gear 49, and the left operation shaft 48 are operated. 6, the left shift fork 46 swings leftward in FIG. 6, and the left holder 32 is slid leftward to interrupt transmission to the left axle 3b. As a result, a left-turning state with the cultivating rotor 4 attached to the left axle 3b as a fulcrum by the thrust of the tilling rotor 4 attached to the right axle 3a can appear. Conversely, when the right steering lever 53 (clutch operating tool) is gripped and operated during work, the right wire 54, the right linkage arm 52, the right linkage shaft 50, the right bevel gear 49 and the right operation shaft 48 are operated. As shown in FIG. 6, the right shift fork 46 swings in the right direction, and the right holder 32 is slid in the right direction to block transmission to the right axle 3a. As a result, a right-turning state with the cultivating rotor 4 attached to the right axle 3a as a fulcrum by the thrust of the tilling rotor 4 attached to the left axle 3b can be revealed. That is, during the turning operation, the turning operation such as the small turn of the airframe can be easily performed, so that the work efficiency can be improved.

  When the left and right steering levers 53 are released, the left and right holders 32 are returned to the clutch-engaged positions by the urging forces of the left and right springs 41 provided on the left and right side clutches 15 and 15, and the left and right axles 3a. , 3b is driven and transmitted so that a straight traveling state can be revealed by the thrust of each tilling rotor 4 mounted on the left and right axles 3a, 3b.

[Another embodiment]
(1) FIGS. 9 and 10 show another embodiment, which is different from the above embodiment in the operation system A2 for engaging and closing the left and right side clutches 15 and 15 and the meshing structure of the side clutch 15. That is, as shown in FIG. 9, the operation shaft 48 that connects the shift fork 46 so as to be swingable about the longitudinal axis P <b> 3 is provided at one place immediately behind the longitudinal transmission shaft 13 in the mission case 2. Yes. The shift fork 46 is U-shaped in a plan view, and an operation shaft 48 is fixed to the center of the base of the shift fork 46. A pair of engaging portions 47 formed at the left and right free ends of the shift fork 46 are respectively connected to the right holder 32. And is inserted into the circumferential groove 45 of the left holder 32.

  As shown in FIG. 9, when the left and right side clutches 15, 15 are in the engaged state, the second inner convex portion 39 and the second outer convex portion 40 are engaged with the first inner convex portion 35 and the first outer convex portion 36. The combined depth is engaged at a depth less than half of the depth of the first inner convex portion 35 and the first outer convex portion 36 (the depth of the second inner concave portion 41 and the second outer concave portion 42).

  A bevel gear 49 is connected to the upper end of the operation shaft 48 so as to rotate integrally around the vertical axis P3. The bevel gear 49 meshes with a bevel gear 51 that rotates together with a linkage shaft 50 that is supported on the transmission case 2 so as to be rotatable around the tilt axis P4. A linkage arm 52 is fixed to the outer end of the linkage shaft 50. The linkage arm 52 is linked via a linkage member 54 made of a wire to a clutch operating tool 55 supported on the upper side of the left steering handle 8 so as to swing left and right.

  When the left and right side clutches 15 and 15 are in the engaged state and the clutch operating tool 55 is operated to rotate the operating shaft 48 clockwise in FIG. 9, the shift fork 46 is centered on the vertical axis P3 of the operating shaft 48. The right and left holders 32 that rotate to the right and engage with the engaging portions 47 at the left and right ends of the shift fork 46 move to the right, and the second inner convex portion 39 and the second outer convex portion 40 of the right holder 32 are moved. The large-diameter bevel gear 29 is separated from the first inner convex portion 35 and the first outer convex portion 36. At the same time, the second inner convex portion 39 and the second outer convex portion 40 of the left holder 32 engage more deeply with the left first inner convex portion 35 and the first outer convex portion 36, and the left side clutch 15 Keep the state of entering.

  Conversely, when the left and right side clutches 15 and 15 are in the engaged state and the clutch operating tool 55 is operated to rotate the operating shaft 48 counterclockwise in FIG. 9, the operating shaft 48 shifts about the vertical axis P3. The fork 46 rotates counterclockwise, the left and right holders 32 engaged with the engaging portions 47 at the left and right ends of the shift fork 46 move to the left side, and the right side clutch 15 is kept engaged, The 32 second inner convex portions 39 and the second outer convex portions 40 are separated from the left first inner convex portion 35 and the first outer convex portion 36, and the left side clutch 15 is disengaged.

  When the operating force of the clutch operating tool 55 is released, the shift fork 46 returns to the original state by the biasing force of the spring 44, and the left and right holders 32 return to the center left and right clutch engagement positions and are transmitted to the left and right axles 3a and 3b. Thus, it is possible to show the straight traveling state by the thrust of each tilling rotor 4 mounted on the left and right axles 3a, 3b.

(2) In the main embodiment, the first inner convex portion 35 and the first outer convex portion on the large-diameter bevel gear 29 side that engage with the second inner convex portion 39 and the second outer convex portion 40 formed at a small angle. 36 is formed by a first inner convex portion 35 and a first outer convex portion 36 that are individually inner and outer. However, as shown in FIG. 11, the first inner convex portion 35 and the first outer convex portion 36 are integrally formed. The fixed clutch pawl 31 may be configured.

(3) In the main embodiment, the outer peripheral surface of the first inner convex portion 35 of the large-diameter bevel gear 29, the inner peripheral surface of the second outer convex portion 40 of the holder 32, and the first outer convex portion 36 of the large-diameter bevel gear 29. The first radius R1 and the second radius R2 are set so that the inner peripheral surface of the holder 32 and the outer peripheral surface of the second inner convex portion 39 of the holder 32 are close to each other. Is not wide as shown in the drawings, and is arranged so close that the inner and outer peripheral surfaces are in contact with each other. On the other hand, when the outer peripheral surfaces of the inner first inner convex portion 35 and the second inner convex portion 39 and the inner peripheral surfaces of the outer first outer convex portion 36 and the second outer convex portion 40 are engaged with each other. It may be configured to always contact.

(4) Although the side clutch 15 is configured as a pair of left and right side clutches 15 and 15 in the main embodiment, the large-diameter bevel gear 29 and the right axle 3a are always rotated by spline or key connection. By configuring, the side clutch 15 may be provided only between the left axle 3 b and the large-diameter bevel gear 29.

(5) In the main embodiment, the second inner convex portion 39 and the second outer convex portion 40 formed in the position of the phase difference of 180 degrees separated from the movable holder 32 in the circumferential direction are similarly arranged in the circumferential direction. Although it is configured to fit into the first inner concave portion 37 and the first outer concave portion 38 formed at a phase difference position of 180 degrees apart, the second inner convex portion 39 or the second outer convex portion is formed on the holder 32. The third protrusion (not shown) on the same circumference as 40, or the third protrusion (not shown) on the circumference of a third radius different from the circumference of the second inner protrusion 39 and the second outer protrusion 40 And a third concave portion in which the third convex portion is fitted to the large-diameter bevel gear 29 (if formed on the circumference of the third radius, the third convex portion is formed between the third convex portions. 3 recesses) may be formed. As described above, when the holder 32 is provided with the three convex portions and the large-diameter bevel gear 29 with the three concave portions corresponding thereto, the three convex portions and the concave portions are formed at the positions of the phase difference of 180 degrees. It is desirable to form in the position of the phase difference of about 120 degree | times.

(6) In the main embodiment and (1) to (5), a plurality of first inner convex portions 35 and first inner concave portions 37 are formed, and the second inner concave portions 41 and the second inner convex portions are correspondingly formed. A plurality of portions 39 may be formed. A plurality of first outer convex portions 36 and first outer concave portions 38 may be formed, and a plurality of second outer concave portions 42 and second outer convex portions 40 may be formed correspondingly.
In the main embodiments and (1) to (5), the first inner convex portion 35 and the first inner concave portion 37 are formed in the holder 32, and the second inner concave portion 41 and the second inner convex portion 39 are correspondingly formed. May be formed on the large-diameter bevel gear 29. On the contrary, the first outer convex portion 36 and the first outer concave portion 38 are formed on the holder 32, and the second outer concave portion 42 and the second outer convex portion 40 are formed on the large-diameter bevel gear 29 correspondingly. Also good.

[Comparative Example]
FIGS. 12, 13, and 14 are examples of the dog clutch fixed clutch pawls 61 and 62 and the movable clutch pawls 63 and 64 that are always meshed at only one place, and show a comparative example with respect to the embodiment of the present invention. The clutch operation system A3 of this comparative example has the same structure as the operation system A2 of FIGS. It differs from the present invention in the structure of the clutch pawls of the side clutches 15 and 15. That is, the two fixed clutch pawls 61 and 62 formed on the large-diameter bevel gear 29 and the two movable clutch pawls 63 and 64 formed on the holder 32 are all located on the same circumference with the same radius R3 and are approximately 180 °. Although projecting at the phase difference position, the circumferential length S1 of the first recess 65 and the circumferential direction of the second recess 66 are engaged with the movable clutch pawls 63 and 64 and the movable clutch pawls 63 and 64. By making the circumferential length S2 different, it is possible to mesh only at one place in one rotation.
In this case, when the large-diameter bevel gear 29 is swung in the axial direction with respect to the shaft, when the side clutch 15 is engaged, the movable clutch pawl 63 having the shorter peripheral length of the movable clutch pawls 63 and 64 is moved. There is a possibility that the end of the movable clutch pawl 63 is caught by the end edges of the fixed clutch pawls 61 and 62 by being fitted into the second recess 66 having the longer circumference. Also, if the protruding length of the movable clutch pawl 63 is longer than the protruding length of the movable clutch pawl 64 due to manufacturing errors or the like, when the side clutch 15 is engaged and operated, the shorter peripheral length of the movable clutch pawls 63, 64 There is a possibility that the movable clutch pawl 63 is fitted in the second recess 66 having the longer peripheral length, and similarly, the end of the movable clutch pawl 63 is caught by the end edges of the fixed clutch pawls 61 and 62.

  On the other hand, as in the main embodiment, the outer peripheral surface of the first inner convex portion 35 of the large-diameter bevel gear 29, the inner peripheral surface of the second outer convex portion 40 of the holder 32, and the first of the large-diameter bevel gear 29. The inner peripheral surface of the outer convex portion 36 and the outer peripheral surface of the second inner convex portion 39 of the holder 32 are arranged close to or in contact with each other, and the first inner convex portion 35 of the large-diameter bevel gear 29 and the second inner surface of the holder 32 are If the convex portion 39 and the first outer convex portion 36 of the large-diameter bevel gear 29 and the second outer convex portion 40 of the holder 32 are configured to mesh with each other only at one location in the same circumferential direction, the meshing on the radially inner side is also possible. Since there is only one meshing portion for each of the outer meshes per rotation, even if the projecting length of the second inner projecting portion 39 is longer than the projecting length of the second outer projecting portion 40, the second inner projecting portion 39 is Only by sliding in contact with the tip of the inner convex portion 35, a predetermined first Because until the recess 37 and the fitting clutch does not move in the direction to enter, will not be the second in a convex portion 39 biting the first inner projections 35 on the way. Therefore, there is little occurrence of abnormal noise.

3 axle 3a axle (right axle)
3b Axle (left axle)
5 Tilling shaft 7 Tilling claw 15 Side clutch 29 Drive section (large diameter bevel gear)
35 First inner convex portion 36 First outer convex portion 37 First inner concave portion 38 First outer concave portion 39 Second inner convex portion 40 Second outer convex portion 41 Second inner concave portion 42 Second outer concave portion 53 Clutch operating tool Direction lever)
R1 first radius R2 second radius

Claims (4)

The drive unit that transmits power to the axle that connects the tilling shaft with the tilling claw to the left and right and the axle are arranged concentrically, and the drive unit and the axle are placed between the drive state and the non-drive state. A side clutch,
A first inner recess is provided on one of the drive unit and the axle at a position of a first radius from the rotation center of the axle, and the first inner projection is circumferentially adjacent to the first inner recess. A second inner convex portion and a second inner concave portion that engage with the first inner concave portion and the first inner convex portion, respectively, on the other side of the axle;
A first outer concave portion and a first outer convex portion adjacent to the first outer concave portion at one of the driving portion and the axle at a position of a second radius larger than the first radius from the rotation center of the axle; A second outer convex portion and a second outer concave portion that are engaged with the first outer concave portion and the first outer convex portion, respectively, on the other of the portion and the axle,
The first inner convex portion and the first outer convex portion engage with the second inner concave portion and the second outer concave portion, respectively, and the second inner convex portion and the second outer convex portion are the first inner concave portion and the second outer concave portion, respectively. By engaging the first outer concave portion, the first inner convex portion and the second inner convex portion are engaged with each other, and the first outer convex portion and the second outer convex portion are engaged with each other. Configure
The outer peripheral surface of the first inner convex portion and the inner peripheral surface of the second outer convex portion are close to or abut, and the outer peripheral surface of the second inner convex portion and the inner peripheral surface of the first outer convex portion are close or Set the first radius and the second radius so that they touch each other,
The phase of the first inner convex portion and the second inner convex portion, or the phase of the first outer convex portion and the second outer convex portion so that the side clutch is engaged only in one phase in the rotational direction. A walk-type work machine that has been set up.   The first inner recess and the first outer recess are formed at a phase difference of 180 degrees, and the second inner protrusion and the second outer protrusion are formed at a phase difference of 180 degrees. The walking work machine according to claim 1.   The walking work machine according to claim 1 or 2, wherein the side clutch includes a right side clutch that can be transmitted to and disconnected from a right axle, and a left side clutch that can be transmitted to and disconnected from a left axle.   4. The walking type work machine according to claim 3, wherein the left and right side clutches are configured to be interlocked with a right clutch operating tool and a left clutch operating tool separately for each left and right, so that the left and right side clutches can be separated from each other.

Images