JPH08191620A - Mechanism for transmitting power - Google Patents

Abstract

PURPOSE: To provide a mechanism for transmitting a power capable of tilting a tiltable part within a wide range without applying any excessive force. CONSTITUTION: This mechanism for transmitting a power comprises a fixed part A and a tiltable part B based on the fixed part A and is capable of transmitting a driving force of a prime mover 1 provided on the side of the fixed part A to the side of the tiltable part B. A transmitting shaft 31 is installed along the central axial line 26 of tilting of the tiltable part B so as to perform the transmission of the driving force from the prime mover 1 through the transmission shaft 31 to the side of the tiltable part B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism that includes a fixed portion and a tilting portion based on the fixed portion, and that transmits the driving force of a prime mover provided on the fixed portion side to the tilting portion side. , A safety device in such a power transmission mechanism. These inventions are suitable techniques to be applied to, for example, a mower or the like including a rotary blade on the tilting portion side, and the rotary blade being driven by the prime mover on the fixed portion side.

[0002]

2. Description of the Related Art As a mower for ridges, a plane cutting blade that rotates along the upper surface of the ridge that is substantially horizontal and a slope cutting blade that rotates along the slope of the ridge that is substantially downwardly inclined. There is known a system in which the cutting blades are provided on the left and right sides, and the both cutting blades are rotationally driven by the power of a prime mover mounted on the machine body.

In such a mowing machine, the slope cutting blade has an outer side that can be vertically tilted. This is because the slope angle of the slope cutting blade can be made to correspond to slopes of ridges having various slope angles each time.

By the way, the operative connection between the tiltable slope cutting blade and the prime mover arranged on the fixed side is as follows.
Conventionally, for example, it has been performed as follows.

The body of the mower comprises a fixed part and a tilting part based on the fixed part. The tilting portion is supported by a pivot extending in the front-rear direction of the machine body so as to be vertically tiltable in contact with a side edge of the fixed portion in the front-rear direction.

The tilting portion can be fixed by appropriate fixing means by selecting the tilt angle so as to face the slope of the ridge.

The fixed portion includes the plane cutting blade, and the tilting portion includes the slope cutting blade. The rotary shaft of each cutting blade projects upward at right angles to the upper surfaces of the fixed portion and the tilting portion. A first pulley for a flat cutting blade and a second pulley for a flat cutting blade are fixed to a rotary shaft of the flat cutting blade. A pulley for a slope cutting blade is fixed to a rotary shaft of the slope cutting blade.

The prime mover is arranged on the fixed portion side of the machine body. A prime mover pulley is fixed to the output shaft of the prime mover.

A first belt is loosely wound around the drive pulley and the first pulley for the plane cutting blade. A second belt is loosely wound between the second pulley for flat cutting blade and the pulley for slope cutting blade.
The second belt straddles between the fixed portion and the tilting portion and is located above them.

A first tension roller is displaceably provided near the first belt. The first tension roller performs a pressure contact operation with the first belt and a separation operation from the first belt. These displacement operations are performed by operating a shift lever provided near the handle of the mower. The first tension roller controls the tension of the first belt to control power transmission from the prime mover to the flat cutting blade.

A second tension roller is provided near the second belt. The second tension roller is constantly in pressure contact with the second belt by a spring. The second tension roller constantly applies a tension to the second belt to operatively connect the plane cutting blade and the slope cutting blade at all times.

The conventional structure as described above is disclosed in, for example, Japanese Patent Laid-Open No. 5-30837 (see FIG. 5 in the publication).
It is described in.

The conventional grass mower operates as follows.

First, the fixed portion of the body of the mower is placed on the ridge so that the plane cutting blade faces the horizontal upper surface of the ridge. Next, the tilting portion is tilted according to the tilt angle of the slope of the ridge, and the tilting portion is fixed by the fixing means so as to maintain the tilt angle. As a result, the slope cutting blade faces the slope of the ridge. At this time, the second belt,
The fixed portion and the tilting portion straddle in an inclined state.

The shift lever is operated to bring the first tension roller into pressure contact with the first belt to apply tension to the first belt. When a predetermined tension is applied to the first belt, the driving pulley and the first pulley for flat cutting blade are operatively connected to each other to transmit power to the flat cutting blade.

On the other hand, the first pulley for the flat cutting blade and the pulley for the slope cutting blade are operatively connected to each other by the second belt and the second tension roller.
Therefore, the power of the prime mover is also transmitted to the slope cutting blade via the plane cutting blade, and the plane cutting blade starts at the same time as the slope cutting blade starts.

[0017]

According to the conventional mower, the slope cutting blade pulley fixed to the rotary shaft of the slope cutting blade and the plane cutting fixed to the rotary shaft of the flat cutting blade. The blade second pulley was operatively connected by the second belt and the second tension roller. Therefore, when the tilting portion is tilted largely downward, the second belt may come into contact with the connecting portion between the fixed portion and the tilting portion. Therefore, there is a limit to the downward tilt angle of the tilting portion, and depending on the shape of the ridge,
If the slope cutting blade continues to rotate as it is, the belt may be cut and unusable.

Further, in the above-mentioned conventional mower, it is difficult to mow a so-called upward slope inclined obliquely upward from the side edge of the upper surface of the ridge. Since the power transmission from the prime mover to the slope cutting blade is a belt transmission system, when the tilting portion is tilted largely upward, the second belt comes off and the like, so that the slope cutting blade is removed from the prime mover. This is because it becomes impossible to transmit power to. Furthermore, since the slope cutting blade is rotating even when it is not necessary to use the slope cutting blade, it is very dangerous to tilt the tilting portion upward.

The present invention has been made in view of the above circumstances, and the first problem to be solved is to provide a grass mower or the like capable of reasonably tilting the tilting portion in a large range. It is to provide a suitable power transmission mechanism.

The second problem to be solved is, in such a power transmission mechanism, the tilting portion has a predetermined tilt angle (for example, in the case of the mower, the slope cutting blade is exposed, It is an object of the present invention to provide a power transmission safety device that automatically stops power transmission from the prime mover to the tilting portion side when the inclination angle is a large upward angle.

[0021]

In order to solve the first problem, a power transmission mechanism according to the present invention includes a fixed portion and a tilting portion based on the fixed portion, and is provided on the fixed portion side. A mechanism for transmitting a driving force of a prime mover provided to the tilting portion side, wherein a transmission shaft is provided along a central axis of tilting of the tilting portion, and from the prime mover to the tilting portion side via the transmission shaft. The driving force is transmitted.

Further, in order to solve the second problem, the power transmission safety device according to the present invention has a structure in which the tilted portion has a predetermined tilt angle or more and a predetermined tilt angle or less. Inclination angle detecting means that operates according to the tilting operation, a shift lever that controls the transmission of the driving force from the prime mover to the tilting portion side, and a lever path that opens and closes the movement path of the lever to the driving force transmission shift state. Opening and closing means, and when the tilting portion closes the moving path of the lever when the tilting portion becomes equal to or larger than the predetermined tilt angle, and the tilting portion becomes equal to or smaller than the predetermined tilt angle. In addition, the inclination angle detecting means and the lever path opening / closing means are operatively connected so that the lever path opening / closing means opens the movement path of the lever.

In such a power transmission safety device, the movement path of the shift lever is formed by a lever guide member, and a lever retaining recess for holding the lever in the driving force transmission shift state is formed in the lever guide member. It is more preferable to close the moving path of the lever by operating the lever path opening / closing means in the direction of pushing the lever out of the lever retaining recess.

[0024]

According to the present invention for solving the first problem, a transmission shaft is provided along the central axis of tilting of the tilting portion,
Since the driving force is transmitted from the prime mover to the tilting portion side via this transmission shaft, even if the tilting portion has a large inclination angle, the driving force transmission system is not hindered.

Further, according to the present invention for solving the second problem, when the tilting portion is set to a predetermined tilt angle or more (for example, when it is tilted largely upward or downward), the tilting operation is performed. In response to this, the inclination angle detecting means operates. Along with the operation of the detecting means, the lever path opening / closing means closes the moving path of the shift lever to the driving force transmission shift state. As a result, the shift lever cannot move to the driving force transmission shift state, so there is no risk of accidentally transmitting power to the tilting portion side due to an operation error or the like.

On the other hand, if the tilt of the tilting portion is within the normal use range of the predetermined tilt angle or less, the tilt angle detecting means operates in the opposite direction according to the tilting operation. With the operation of the detection means, the lever path opening / closing means opens the movement path of the shift lever which has been closed until then. Therefore, the shift lever can be moved to the driving force transmission shift state.

According to the present invention as set forth in claim 3,
The tilting portion while the shift lever is in a driving force transmission shift state (that is, while the shift lever is held in the lever retaining recess of the lever guide member while transmitting power to the tilting portion side). When the lever is tilted by the predetermined tilt angle or more, the lever path opening / closing means operates in a direction to push the shift lever out of the lever retaining recess to automatically close the moving path of the shift lever. Therefore, the drive force transmission shift state of the shift lever is released, the power transmission to the tilting portion side is automatically cut off, and the shift lever cannot be moved to the drive force transmission shift state as it is. .

[0028]

An embodiment of the present invention will be described in detail with reference to the drawings.

First, the basic structure of a mower as an example of a specific device having the power transmission mechanism according to this embodiment will be outlined.

As shown in FIGS. 1 to 3, the body 13 of the mower according to the present embodiment is composed of a fixed portion A and a tilting portion B. The tilting portion B is supported on the side portion of the fixed portion A by a support shaft 26 (see FIG. 1) extending in the front-rear direction of the machine body 13 and can be tilted up and down about the axis of the support shaft 26. Has become. In addition, in this specification, the fixed portion is a concept with respect to the tilting portion, and means a portion which is a basis of tilting of the tilting portion.

As shown in FIGS. 2 and 3, a vertical axis type air-cooled gasoline engine 1 is mounted as a prime mover on the fixed portion A side, and a guide wheel 2 is provided at the front part and a drive rear wheel 3 is provided at the rear part. Is equipped with. The driven rear wheels 3 are driven by the engine 1 to apply propulsive force to the machine body 13. An operation handle 4 is provided on the fixed portion A side, and the handle 4 extends in a bifurcated manner obliquely upward and rearward of the machine body 13. Further, the fixed portion A
On the side between the guide wheel 2 and the drive rear wheel 3,
A plane cutting blade 5 which is a horizontal rotary blade is provided.

2 and 3, 50 is the handle 4
The throttle lever of the engine 1 attached to
Reference numeral 51 is a recoil starter of the engine 1.

On the other hand, the tilting portion B is mainly composed of a cover-shaped tilting housing 41 and a slope cutting blade 6 which is a rotary blade housed in the tilting housing 41. The tilting housing 41 is tiltably supported on the side portion of the fixed portion A by the support shaft 26.
Then, in response to the tilting housing 41 tilting, the slope cutting blade 6 also tilts up and down about the support shaft 26.

A method of adjusting the tilt angle of the tilt housing 41 and a specific means for fixing the tilt angle in a desired tilted state will be described with reference to FIGS. 1 and 4. The tilt housing 41 is integrally provided with a tilt angle adjusting plate 45 on its upper surface. This adjustment plate 45
Has an appropriate number of adjusting holes 45a. It is preferable that these adjustment holes 45a are located on an arc centered on the support shaft 26 when viewed from the front-rear direction of the machine body 13.

On the other hand, on the fixed portion A side of the machine body 13, an inclination angle adjusting pin 46 which is movable in the front-rear direction of the machine body 13 is provided via a plate-shaped bracket 13c parallel to the adjusting plate 45. Has been. The pin 46 penetrates the bracket 13c forward and projects into the adjusting hole 45a of the adjusting plate 45. The pin 46 is constantly urged forward by a pin urging spring body 46a so as to maintain a state of being thrust into the adjustment hole 45a.

In the illustrated mower, the tilting housing 41 can be fixed so as to maintain the horizontal state, and can be fixed by changing the tilt angle stepwise upward, while it can be fixed downward. In the tilted state, it is not fixed and is free up to about 60 degrees.

The fixed portion A of the tilting housing 41
When adjusting the inclination angle with respect to, the pin 46 is slid backward of the machine body 13 against the biasing force of the spring body 46a. As a result, the pin 46 comes out of the adjustment hole 45a, so that the tilting housing 41 can freely tilt about the support shaft 26.
Therefore, if the gripping rod 47 provided on the tilting housing 41 is grasped, the tilting housing 41 is moved upward or downward to a desired tilt angle, and a new adjusting hole 45a is selected to release the pin 46. The pin 46 projects into the new adjustment hole 45a by the biasing force of the spring body 46a. In this way, the tilt housing 41 is fixed so as to maintain the new tilt angle.

In FIG. 1, reference numeral 52 is an auxiliary wheel provided on the tilting housing 41. The auxiliary wheel 52 acts to support the tilting housing 41 in accordance with the tilted state of the slope of the ridge when the tilting housing 41 is freed downward (see FIG. 3). Further, in FIG. 4, 41a is a skirt made of rubber or the like provided on the outer side and the rear side of the tilting housing 41. The skirt 41a prevents the cut grass from scattering laterally and rearward (toward the operator) of the machine body 13 by the rotation of the slope cutting blade 6.

The plane cutting blade 5 is rotated by the engine 1 together with the slope cutting blade 6 or independently. The slope cutting blade 6 is located diagonally rearward of the plane cutting blade 5 (in the illustrated example, diagonally leftward rearward as shown in FIG. 1). The plane cutting blade 5 and the slope cutting blade 6 are, as shown in FIG. 1, to prevent uncut portions between them.
They overlap each other in the left-right direction by a predetermined width X.

The drive of the drive rear wheel 3 will be described with reference to FIG. The engine 1 is arranged with its output shaft 1a facing downward. A wheel drive pulley 7 is fixed to the output shaft 1a. On the other hand, a transmission pulley 8 is arranged near the drive rear wheel 3 with its support shaft oriented in the vertical direction. The transmission pulley 8 is drivingly connected to the driving rear wheel 3 via a speed reducer 10. A wheel drive belt 9 is loosely wound between the transmission pulley 8 and the wheel drive pulley 7.

In FIG. 1, reference numeral 11 is a traveling clutch. The traveling clutch 11 includes a swing lever 14. The swing lever 14 is pivotally fixed to the machine body 13 by a pin 12 at its base end. Links 16 and 17 are connected to the base end side of the swing lever 14. The link 17 is operatively connected to a traveling clutch lever 18 attached to the operation handle 4.

On the other hand, a tension roller 15 is provided at the rocking end of the rocking lever 14 so as to press the wheel drive belt 9 and apply a predetermined tension thereto.

In the above-mentioned structure, when the traveling clutch lever 18 is not pulled, the wheel drive belt 9 is loose. Therefore, even if the engine 1 is started,
The rotation of the wheel drive pulley 7 is not transmitted to the transmission pulley 8. On the other hand, when the running clutch lever 18 is pulled after the engine 1 is started, the tension roller 15 comes into pressure contact with the wheel drive belt 9 via the links 17 and 16 and the swing lever 14. As a result, a predetermined tension is applied to the wheel drive belt 9, and the wheel drive pulley 7 and the transmission pulley 8 are operatively connected. As a result, the drive rear wheels 3 are rotationally driven through the speed reducer 10 so as to advance the machine body 13.

Next, from the engine 1 to the plane cutting blade 5
A drive force transmission system for the slope cutting blade 6 will be described.

FIG. 1 and FIG. 5 showing a part thereof in an enlarged manner.
As shown in, the output shaft 1a of the engine 1 is
The cutting blade drive pulley 19 is fixed as a driving pulley. On the other hand, a first pulley 20 for a flat cutting blade is fixed to a rotary shaft 5a of the flat cutting blade 5. A first V-belt 21 for driving the cutting blade (hereinafter, shown as a flat belt for simplification of the illustration) is loosely provided between the first pulley 20 for the flat blade and the pulley 19 for driving the cutting blade. It is wrapped around.

A rotatable first tension roller 22 is arranged outside the first belt 21. The first tension roller 22 is used for the first belt 2
It can be displaced in a direction in which it is pressed against 1 to give a predetermined tension and a direction in which the tension is released.

A second pulley 27 for a flat cutting blade is fixed to the rotary shaft 5a of the flat cutting blade 5. Lateral side of the second pulley 27 for plane cutting blade (left side of the machine body 13 in the illustrated example)
Is provided with a slope cutting blade pulley 28. The slope cutting blade pulley 28 is attached to the machine body 13 with its rotating shaft 28a oriented vertically.

A second V-belt 29 for driving the cutting blade is provided between the second pulley 27 for the flat cutting blade and the pulley 28 for the slope cutting blade (for the sake of simplification of the drawing, a flat belt is shown below). It is wrapped around loosely. On the outside of the second belt 29, the rotatable second tension roller 4 is provided.
8 are arranged. This second tension roller 48
Are displaceable in a direction in which the second belt 29 is brought into pressure contact with the second belt 29 to apply tension and a direction in which the tension is released.

As shown in FIG. 1, a drive bevel gear 30 is provided at the upper end of the rotary shaft 28a of the slope cutting blade pulley 28.
Is stuck. A driven bevel gear 32 fixed to the front end of the transmission shaft 31 meshes with the drive bevel gear 30. The transmission shaft 31 includes the tilting housing 4
Along one of the support shafts 26, the support shaft 26 is horizontally supported in the front-rear direction of the machine body 13. An intermediate drive timing pulley 33 is provided at the rear end of the transmission shaft 31.

The machine body 13 has a rectangular rod-shaped movable rod 34 extending in the left-right direction. The intermediate drive timing pulley 33 is housed inside the base end of the movable rod 34. The movable rod 34 is located above the front part of the slope cutting blade 6. The movable rod 34 is configured such that the outer end side of the movable rod 34 can freely swing up and down about the intermediate drive timing pulley 33 (see FIG. 3).

An intermediate driven timing pulley 35 having a support shaft 35a in the front-rear direction is housed inside the swinging end (outer end) of the movable rod 34. A timing belt 36 is wound around the intermediate driven timing pulley 35 and the intermediate drive timing pulley 33.

A connecting rod 37 in the form of a rectangular tube extending inward (toward the fixed portion A) is connected to the outer end of the movable rod 34. A drive timing pulley 38 is housed inside the outer end of the connecting rod 37. The drive timing pulley 38 is provided on a support shaft 35a common to the intermediate driven timing pulley 35. The connecting rod 37 is a support shaft 35a of the drive timing pulley 38.
The inner end side of which is freely swingable up and down.

A driven timing pulley 39 having a front-rear rotating shaft 42 is housed inside the swinging end (inner end) of the connecting rod 37. A timing belt 40 is wound around the driven timing pulley 39 and the drive timing pulley 38.

The rotary shaft 42 of the driven timing pulley 39 extends rearward from the swinging end of the connecting rod 37. A drive bevel gear 43 is fixed to the rear end of the rotary shaft 42. This bevel gear 43
The driven bevel gear 44 fixed to the upper end of the rotary shaft 6a of the slope cutting blade 6 meshes with the driven bevel gear 44.

As already mentioned, the tilting housing 4
1 can be tilted about the axis of the support shaft 26 and can be fixed so as to maintain a desired tilt angle. FIG. 9 shows a state when the tilting housing 41 tilts, as viewed from the rear of the machine body 13.

In FIG. 9, a first arc C1 is a locus drawn by the rotary shaft 42 when the tilt housing 41 tilts, and a second arc C2 indicates the intermediate driven timing pulley 35 and the drive timing. It is a locus drawn by the common support shaft 35a with the pulley 38. The first arc C
1 is an arc centered on the support shaft 26, and the second arc C2 is an arc centered on the transmission shaft 31.
Then, the connecting rod 37 moves between the second arc C2 and the first arc C1.

Now, the center of the transmission shaft 31 is P, the center of the common support shaft 35a is Q, the center of the rotary shaft 42 is R,
The center of the support shaft 26 is S. At this time, the connection of the tilting housing 41 to the fixed portion A is substantially a limited chain in which the line segment SP is a fixed link by four links indicated by line segments PQ, QR, RS, and SP. Has become.

Then, as described above, the fixed portion A
The power transmission system from the rotary shaft 28a of the pulley 28 for the slope cutting blade provided on the side to the slope cutting blade 6 substantially exists along the link. Therefore, even if the tilting housing 41 is tilted largely up and down, the fixed portion A
There is no obstacle to the power transmission from the side to the slope cutting blade 6. Therefore, the tilting housing 41 is folded to the fixed portion A side as required, and only the upper surface of the narrow ridge is mowed by using only the plane cutting blade 5, or so-called upward slope cutting is performed. be able to.

Further, since the body 13 can be made compact by folding the tilting housing 41 toward the fixed portion A side, it is convenient for transportation and storage.

Further, since the tilting angle of the tilting housing 41 can be variously changed, the mowing work can be performed.
It can be applied to work sites of various terrain.

Next, with reference to FIG. 5 to FIG. 8, the control means of the power transmission from the engine 1 to the plane cutting blade 5 and the slope cutting blade 6 will be described.

The machine body 13a includes a vertical support shaft 60.
The actuating lever 61 is rotatably attached by. The actuating lever 61 is for operating the first tension roller 22 so as to come into pressure contact with the outer peripheral surface of the first belt 21.

Between the operating lever 61 and the first tension roller 22, a torsion coil spring-shaped roller pressure contact spring body 64 is provided. The spring body 64 acts to transmit the turning force of the actuating lever 61 as a pressure contact force of the first tension roller 22 to the first belt 21.

The spring force of the spring body 64 is set so that the turning force of the actuating lever 61 acts on the first belt 21 until the first belt 21 has a predetermined tension suitable for power transmission. The pressure is transmitted as the pressure contact force of the first tension roller 22, but when the tension of the first belt 21 reaches a predetermined level, the force is not further transmitted.

In the illustrated example, a first tension roller arm 62 is rotatably attached to the support shaft 60 of the operating lever 61 at the base end side thereof. On the tip side of the first tension roller arm 62,
The first tension roller 22 is rotatably provided by a vertical support shaft 63.

The first tension roller arm 62.
The torsion coil spring 64 for urging the spring bodies 64 in directions opposite to each other is provided between the operating lever 61 and the operating lever 61. This coil spring 64
Always urges the first tension roller arm 62 in a direction in which the first tension roller 22 presses the first belt 21 to apply tension. The coil spring 64 has its winding start end 64a hooked on the first tension roller arm 62, and its winding end 64b hooked on the operating lever 61, so that the spindle 60 of the operating lever 61 is hooked. It is provided around.

The first tension roller arm 62.
Has integrally an extending portion 65 extending upward toward the operating lever 61 side. The first tension roller arm 62 and the operating lever 61 are urged in the opposite rotational directions by the coil spring 64, and the extension portion 65 and the swinging end 61a side of the operating lever 61 are normally in contact with each other. Are integrated with each other by abutting each other.

A front end portion 25a of a shift operation push-pull cable 25 is connected to the operation end 61b side of the operating lever 61. This shift operation cable 25 extends to the rear of the machine body 13 and has a rear end portion 2
5b is connected to the shift lever 24.

As shown in FIGS. 2, 5 and 12, the shift lever 24 is pivotally supported by a lever support shaft 4a on a shift lever guide member 24c attached to the operation handle 4, and the guide member is provided. It is swingable in the front-back direction along a shift lever guide groove 24d formed in 24c. The guide groove 24d forms a movement path of the shift lever 24, and the shift lever 24
When the shift lever 24 is returned to the front, the shift operation cable 25 is pulled backward, and when the shift lever 24 is returned to the front, the operation cable 25 is returned to the front. In FIG. 12, reference numeral 24e denotes a lever return spring body that always pulls the shift lever 24 forward.

The shift lever guide member 24c has a first-stage locking recess 24a and a second-stage locking recess 24b as lever retaining recesses, and the shift lever guide groove 24d.
And are formed so as to continue smoothly. The shift lever 24 is provided with these locking recesses 24a, 2
4b, the lever return spring body 2 is locked.
It is stopped against the pulling force of 4e.

In the above structure, when the engine 1 is started and the shift lever 24 is pulled so as to be retained in the first-step locking recess 24a, the shift operation cable 25 is pulled backward. The operation end 61b side of the operating lever 61 is pulled rearward (FIG. 5).
reference). Then, the operating lever 61 rotates around the support shaft 60, and the swing end 61a side thereof rotates forward. The rotation of the actuating lever 61 on the swing end 61a side is transmitted to the first tension roller arm 62 via the coil spring 64, and the first tension roller 22 moves to the first belt 21 side. It is pressed against the outer peripheral surface.

As a result, a predetermined tension suitable for power transmission is applied to the first belt 21, and the cutting blade drive pulley 19 and the plane cutting blade first pulley 20 are operatively connected. When the first plane cutting blade pulley 20 rotates, the plane cutting blade 5 rotates via the rotation shaft 5a.

In this embodiment, the shift lever 2
4 is pulled further backward from the first-step locking recess 24a and moved to the second-step locking recess 24b, so that in addition to the flat cutting blade 5, the slope cutting blade 6 also starts to rotate. It is like this.

That is, as shown in FIGS. 5, 7 and 8, the second tension roller arm 67 is rotated near the actuating lever 61 by the vertical support shaft 66 fixed to the machine body 13b. It is movably supported. As shown in FIG. 8, the second tension roller arm 67 is arranged so as to be vertically displaced from the operating lever 61. The second tension roller 48 is rotatably attached to the swing end 67a side of the second tension roller arm 67 by a vertical support shaft 68.

On the operating end 61b side of the operating lever 61, an extending portion 69 extending upward toward the second tension roller arm 67 side is bent and formed at a right angle. The extension portion 69 has a predetermined tension suitable for power transmission to the first belt 21 due to the pressure contact of the first tension roller 22 when the operating lever 61 rotates counterclockwise as viewed in FIG. Is abutted against the operation end 67b side of the second tension roller arm 67. The extending portion 69 causes the turning force of the operating lever 61 to be applied to the second tension roller arm 6
7 to rotate the arm 67.

In the above structure, when the shift lever 24 is further pulled and moved from the first-step locking recess 24a to the second-step locking recess 24b, the actuating lever 61 rotates further. Move. However, since the magnitude of the spring force of the coil spring 64 is as described above, the pressure contact force of the first tension roller 22 with respect to the first belt 21 does not change significantly. That is, there is no change in the degree of tension of the first belt 21,
It does not hinder the transmission of power to the plane cutting blade 5.

When the shift lever 24 is moved from the first-step locking recess 24a to the second-step locking recess 24b to further rotate the operating lever 61, the operating lever 61 moves While the extension portion 69 is in contact with the operation end 67b side of the second tension roller arm 67, they are integrally rotated. That is, the turning force of the operating lever 61 is transmitted to the second tension roller arm 67 via the extending portion 69, and the arm 67 is rotated in the same direction as the operating lever 61. As a result, the second tension roller 48 comes into pressure contact with the outer peripheral surface of the second belt 29,
The second belt 29 has a predetermined tension suitable for power transmission.

When a predetermined tension suitable for power transmission is applied to the second belt 29 as described above, the second plane cutting blade pulley 27 and the slope cutting blade pulley 28 operate. The upper is connected. Therefore, the power of the engine 1 is transmitted to the slope cutting blade pulley 28 via the rotary shaft 5a of the plane cutting blade 5.

When the slope cutting blade pulley 28 rotates,
A drive bevel gear 30, a driven bevel gear 32, a transmission shaft 31, an intermediate drive timing pulley 33, a timing belt 36, an intermediate driven timing pulley 35, and a support shaft 35 in order.
a, drive timing pulley 38, timing belt 4
0, the driven timing pulley 39, the rotary shaft 42, the drive bevel gear 43, and the driven bevel gear 44, the rotational power is transmitted to rotate the slope cutting blade 6 in the same direction as the flat cutting blade 5.

When the shift lever 24 is removed from the second-stage locking recess 24b and returned to the first-stage locking recess 24a, the shift lever cable is moved forward to move the operating lever 61. The operation end 61b side is pushed back forward, and first, the second tension pulley arm 67 is released. For this reason, the pressure contact force of the second tension roller 48 against the second belt 29 is lost, and the power transmission from the second plane cutting blade pulley 27 to the slope cutting blade pulley 28 is cut off. .

Next, when the clutch lever 24 is removed from the first-stage locking recess 24a and returned to the front, the swinging end 61a side of the actuating lever 61 is the extended portion of the first tension roller arm 62. 65, the first tension roller arm 6 is moved in a direction in which the first tension roller 22 moves away from the first belt 21.
2 is returned and rotated. As a result, the pressure contact force of the first tension roller 22 with respect to the first belt 21 is lost, and the power transmission from the driving pulley 19 to the first plane cutting blade first pulley is also cut off.

An embodiment of the safety device for the power transmission mechanism according to the present invention will be described with reference to FIGS. 9 to 14.

As shown in FIGS. 9 and 10, the airframe 1
3, the tilting housing 41 on the side of the fixed portion A.
On the side portion on the side, a dogleg-shaped lever 70 is provided as a tilt angle detecting means of the tilting housing 41. The tilt angle detection lever 70 detects that the tilt housing 41 is tilted by a predetermined angle (for example, α downward from the plane cutting position or β upward), and the tilt angle is less than or equal to the predetermined inclination angles α and β. It acts to detect the existence.

In the illustrated example, the upper swing limit angle β is detected, but a similar one may be provided for detecting the lower swing limit angle α, if necessary.

The tilt angle detection lever 70 is supported so that its pivot shaft 71 is rotatable in the front-rear direction of the machine body 13. In the illustrated example, the tilt housing 41 is tilted most upward. At this time, the left end portion (power point side end portion 70a) is pushed by the connecting rod 37, and the right end portion (action point side end portion 70b) swings clockwise as viewed in FIG. 9 or 10. When the tilting housing 41 descends and comes out of the maximum tilted state, it rotates counterclockwise to return to the original state.

As shown in an enlarged view in FIG. 11, a front end portion 72a of a cable as a safety device operating force transmission member is provided at the end portion 70b of the tilt angle detecting lever 70 on the point of action side.
Is locked. This actuation force transmission cable 72 is initially stretched short in the left-right direction of the machine body 13 and turned to the rear of the machine body 13 via, for example, a pulley (not shown), and finally shown in FIG. Thus, the rear end 72b side is extended to the vicinity of the shift lever guide member 24c.

In the shift lever guide member 24c, from the first-step locking recess 24a to the second-step locking recess 2a.
4b the path of movement of the shift lever 24 (ie,
Lever path opening / closing means 73 is provided for opening / closing a movement path of the shift lever 24 for transmitting the driving force of the engine 1 to the tilted portion B side. The lever path opening / closing means 73 is operatively connected to the tilt angle detection lever 70 by the actuation force transmission cable 72, and when the tilt housing 41 reaches a predetermined tilt angle β, the shift lever 24 is actuated. The movement path is closed, and the movement path of the shift lever 24 is opened when the tilting housing 41 deviates from the predetermined tilt angle β.

In the illustrated example, the lever path opening / closing means 73 is composed of a metallic fan-shaped plate body, and the upper surface of the shift lever guide member 24c is centered on the rear end portion 73a side which is the key portion thereof. It is designed to rotate to the left and right along. The lever path opening / closing means 73 has a lever path blocking rising piece 73b at its front portion, and a lever pushing rising piece 73c at a side portion facing the second-stage locking recess 24b. .

FIG. 13 shows the lever path opening / closing means 73.
The disassembled relationship between the shift lever guide member 24c and the operating force transmission cable 72 is shown.

As shown in FIG. 13, the shift lever guide member 24c has a through hole 74 for attaching a safety device at a position rearward of the second-stage locking recess 24b.
A cylindrical body 75 for transmitting a safety device operating force is inserted into the through hole 74 from below with a certain amount of play so as to be freely rotatable. At the upper end of this cylinder 75,
The rear end portion 73a side of the lever path opening / closing means 73 is fixed.

The base end portion 76a of the cable attachment lever 76 is fitted to the lower portion of the cylindrical body 75 from below with a certain amount of play so that it can be freely rotated. The rear end portion 72b of the actuating force transmission cable 72 is locked to the swing end portion 76b side of the cable attachment lever 76. The cable attaching lever 76 is, for example,
The first tension coil spring 77 (see FIG. 14) that pulls the lever 76 rearward of the machine body 13 and the force point side end portion 70a of the tilt angle detection lever 70 are clockwise as viewed in FIG. 9 or 10. Due to the balance of the pulling force with the second pulling coil spring 78 that urges in the direction, the swing end portion 76b side is normally set to face the left and right direction of the machine body 13.

Further, inside the cylindrical body 75, a cylindrical body support shaft 79 for rotatably supporting the cylindrical body 75 is inserted from below, and the cylindrical body support shaft 79 is used for the shift lever guide. It is fixed to a plate-shaped bracket 80 provided on the member 24c. The bracket 80 also prevents the cable attachment lever 76 from falling out.

The cable attachment lever 76 and the cylindrical body 7
5 is a swing end portion 76 of the cable attachment lever 76.
Projecting pieces 8 that come into close contact with each other when b is swung forward
1, 82 are integrally provided. Further, between the cable attachment lever 76 and the tubular body 75, the cable attachment lever 76 and the tubular body 75 are rotated in opposite directions so that the protruding pieces 81 and 82 are always in close contact with each other. A spring body 83 for urging the lever path opening / closing means for urging is interposed. The spring body 83 is in the shape of a torsion coil spring, and acts to urge the lever path opening / closing means 73 to rotate toward the cable attachment lever 76 side.

Then, as shown in FIG. 14, in a normal state in which the swing end portion 76b side of the cable attachment lever 76 faces the left-right direction of the machine body 13, the lever path opening / closing means 73 shifts the shift. When the movement path of the lever 24 is opened and the swing end portion 76b side of the cable attachment lever 76 is pulled forward by the operating force transmission cable 72, the lever path opening / closing means 73 is opened via the tubular body 75. The shift lever 24 is rotated to close the moving path of the shift lever 24.

The lever path opening / closing means 73 operates in a direction to push the shift lever 24 locked in the second-stage locking recess 24b out of the recess 24b, and the movement path of the shift lever 24. Is configured to close.

The safety device of the power transmission mechanism according to the present embodiment configured as described above operates as follows.

According to the mowing machine of this embodiment, since the power transmission system is not hindered even if the tilting housing 41 is tilted largely upward, for example, when it is desired to mow only the upper surface of a narrow ridge, the tilting housing is used. 41 is the fixed portion A
It can be folded and fixed along the side.

However, when the tilting housing 41 is tilted upward to the maximum tilted state, the slope cutting blade 6 contained therein is exposed. Under such a condition, the shift lever 24 is accidentally moved to the second-stage locking recess 24 by mistake.
When it is moved to b, the slope cutting blade 6 starts to rotate unexpectedly, which is very dangerous. Therefore, by preventing the shift lever 24 from moving to the second-stage locking recess 24b due to an operation error or the like, it is possible to prevent the exposed slope cutting blade 6 from unexpectedly starting to rotate. The safety device according to the present embodiment.

The tilting housing 41 is placed in the maximum tilting state β.
When it is tilted upward, the connecting rod 37, which moves upward accordingly, comes into contact with the force point side end portion 70a of the tilt angle detection lever 70. As a result, the tilt angle detection lever 70 swings, and the swing end portion 76b of the cable attachment lever 76 passes through the actuation force transmission cable 72.
Are pulled forward of the machine body 13. Then, the projecting piece 81 provided on the cable attachment lever 76 presses the projecting piece 82 provided on the tubular body 75 to push the tubular body 75.
Is rotated in the same direction as the cable attachment lever 76.
When the cylindrical body 75 is rotated, the lever path opening / closing means 73 is also rotated accordingly, and the lever path shut-off rising piece 73b of the lever path opening / closing means 73 is used for locking the second stage of the shift lever. The movement path to the recess 24b is closed. The lever path opening / closing means 73 in this state is shown by a chain line in FIG.

As described above, the shift lever 24
Is prevented from being accidentally moved to the second-stage locking recess 24b.

Further, in the safety device according to the present embodiment, the lever path opening / closing means 73 is operated in the direction of pushing the shift lever 24 locked in the second-stage locking recess 24b out of the recess 24b. Then, the moving path of the shift lever 24 is closed. Therefore, the tilting housing 41 is moved upward to the maximum tilted state β while the shift lever 24 is locked in the second-step locking recess 24b (that is, while the slope cutting blade 6 is rotated). When tilted, the lever path opening / closing means 73
The lever pushing rising piece 73c pushes the shift lever 24 out of the second-stage locking recess 24b, and automatically interrupts power transmission to the tilting portion B side.

There is a case where it is desired to rotate the slope cutting blade 6 by inclining the tilting housing 41 upward to the maximum inclination state β in order to perform so-called upward slope cutting. In such a case, the lever path opening / closing means 73, which closes the movement path of the shift lever 24, is further rotated with a finger against the biasing force of the lever path opening / closing means biasing spring body 83. Then, the moving route may be temporarily opened. That is, the lever path opening / closing means 73 is manually rotated largely to the state shown by the chain double-dashed line in FIG. 14 to temporarily allow it to escape, and in the gap, the shift lever 24 is locked for the second step. It may be moved to the recess 24b.

[0103]

According to the first aspect of the present invention, even if the tilting portion has a large tilt angle, there is no problem in the transmission system of the driving force from the prime mover on the fixed portion side to the tilting portion.

According to the second aspect of the present invention, when the tilting portion has a predetermined tilt angle, power is not accidentally transmitted to the tilting portion, which is safe.

Furthermore, according to the present invention of claim 3,
If power is transmitted to the tilting portion side while the tilting portion is set to a predetermined tilt angle, power transmission is automatically cut off, which is even safer.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a power transmission system of a mower equipped with a power transmission mechanism according to an embodiment of the present invention.

FIG. 2 is a perspective view of a mower equipped with the power transmission system of FIG.

3 is a front view of the mower of FIG. 2. FIG.

FIG. 4 is a perspective view showing a method of adjusting a tilt angle of a tilting portion and a specific means for fixing the tilt angle in a desired tilted state.

5 is a schematic plan view of a main part showing a power transmission control means in the power transmission system of FIG. 1. FIG.

6 is a perspective view of an essential part of FIG. 5, showing a relationship between an operating lever and a first tension roller.

FIG. 7 is a perspective view of a main part of FIG. 5, showing a relationship between an operating lever and a second tension roller.

8 is a vertical cross-sectional side view of the main part of FIG. 5, showing a vertical positional relationship between the operating lever, the first tension roller arm, and the second tension roller arm.

9 is a schematic view of the mower shown in FIG. 2 as viewed from the rear, showing a tilting motion state of the tilting part with respect to the fixed part.

10 is a schematic view of the mower of FIG. 2 as seen from the rear,
The maximum inclination state of the tilting portion is shown.

11 is a perspective view of the tilt angle detection lever seen in FIGS. 9 and 10. FIG.

FIG. 12 is a perspective view showing the vicinity of the shift lever seen in FIG.

13 is an exploded perspective view showing the coupling relationship between the lever path opening / closing means, the shift lever guide member, and the safety device operating force transmission cable shown in FIG.

FIG. 14 is a plan view of FIG. 12, showing an operating state of the lever path opening / closing means.

[Explanation of symbols]

 1 prime mover 24 shift lever 24b lever retaining recess 24c lever guide member 26 central axis (supporting shaft) 31 transmission shaft 70 inclination angle detecting means 73 lever path opening / closing means A fixed portion B inclination portion α predetermined inclination angle (downward) β predetermined Tilt angle (upward)

Claims (3)

[Claims] 1. A fixed part (A) and this fixed part (A)
A mechanism for transmitting the driving force of the prime mover (1) provided on the fixed portion (A) side to the tilting portion (B) side, including the tilting portion (B) based on the tilting portion (B). B)
A transmission shaft (31) is provided along the central axis (26) of tilting of the motor, and the driving force is transmitted from the prime mover (1) to the tilting portion (B) via the transmission shaft (31). Power transmission mechanism. 2. When the tilting portion (B) becomes a predetermined tilt angle (α, β) or more and when it becomes a predetermined tilt angle (α, β) or less, it operates according to the tilting motion. Inclination angle detecting means (70) for
A shift lever (24) for controlling the transmission of the driving force from the above to the tilting portion (B) side, and a lever path opening / closing means (73) for opening and closing the movement path of the shift lever (24) to the driving force transmission shift state. The lever path opening / closing means (73) closes the movement path of the lever (24) when the tilting portion (B) becomes equal to or more than the predetermined tilt angle (α, β), and the tilting portion The inclination angle detecting means (70) is arranged so that the lever path opening / closing means (73) opens the movement path of the lever (24) when (B) becomes equal to or less than the predetermined inclination angle (α, β). The power transmission mechanism according to claim 1, wherein the lever path opening / closing means (73) is operatively connected to each other. 3. The movement path of the shift lever (24) is formed by a lever guide member (24c), and
A lever retaining recess (24b) for holding the lever (24) in the driving force transmission shift state is formed in the lever guide member (24c), and the lever (24) is pushed out from the lever retaining recess (24b). The power transmission mechanism according to claim 2, wherein a movement path of the lever (24) is closed by operating the lever path opening / closing means (73).