JP7341488B2 - Walking type work machine - Google Patents

Description

The present invention relates to a walking type work machine.

Conventionally, walk-behind work machines have been known in which a worker performs work using a working part provided on the vehicle body while accompanying the worker while grasping a handle bar provided at the rear of the vehicle body in the direction of movement (forward direction). ing. This type of walk-behind work machine is equipped with a clutch lever near the handlebar, and the transmission of power from the engine to the running wheels is turned on and off by the operator operating the clutch lever. There are some things. In particular, a clutch that is in a transmitting state (on) when the operator grasps the clutch lever together with the handle lever, and is in a disconnecting state (off) when the operator releases the clutch lever is called a dead man's clutch.

However, when reversing a walk-behind work machine, the worker gets caught between the vehicle and an obstacle behind him, including the clutch lever, and is unable to return the clutch lever due to the pinched body, so the power source is disconnected. It may happen that the transmission is not cut off. Examples of cases in which a walk-behind work machine is moved backwards include changing direction (turning/turning around in a narrow space), aligning ridges, and moving the machine in and out of a warehouse.

In response to this, a safety device has been proposed that aims to prevent a worker from getting caught when reversing the vehicle (see, for example, Patent Document 1). Patent Document 1 discloses that a working vehicle with a loop-type handle rod is provided with a clamping rod that protrudes rearward from the rear end of the handle rod, and holding means for holding a dead man's clutch in an "on" state. A technique is disclosed in which the clamping rod can be moved back and forth. According to Patent Document 1, the holding of the holding means can be released by moving the clamping rod forward.

Japanese Patent Application Publication No. 2005-88769

However, in the technique disclosed in Patent Document 1, the holding state of the dead man's clutch can be released only when the worker is compressed almost horizontally by the working device. Therefore, it cannot be applied when the operator is pressed diagonally upward from below by the handle rod.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a walk-behind work machine that can suppress pressure exerted by a handle rod on a worker.

A walk-behind work machine of the present invention includes a vehicle body provided with a working section for performing a predetermined work, a pair of wheels provided on the vehicle body that rotate around a drive shaft, and a drive section that rotates the pair of wheels. a handle rod that is provided at the rear in the direction of travel of the vehicle body and is gripped by an operator; and a handle bar that is provided forward of the pair of wheels of the vehicle body so that the pair of wheels come into contact when the vehicle body is tilted forward. a deformable portion that transitions to a first deformed state upon receiving a force of more than a predetermined value from a surface; and in conjunction with the transition of the deformable portion to the first deformed state, a stop part that forcibly stops rotation; a posture maintenance part that maintains the posture of the handlebar with respect to the vehicle body; and a posture maintenance part that operates in conjunction with the transition of the deformation part to the first deformation state. and a release portion for releasing the function of maintaining the posture of the handle rod .

The walk-behind work machine of the present invention has the effect of suppressing the pressure exerted by the handle rod on the worker.

FIG. 1 is a schematic diagram showing a walking work machine according to a first embodiment (when the inclination detection mechanism is in a first state). FIG. 2(a) is a perspective view showing a cross-sectional state near the lower end of the handle rod, and FIG. 2(b) is a perspective view showing a state of connection of a wire to a rotating member provided on the handle rod. be. It is a figure which shows the display board provided near the lower end part of a gearshift lever. FIG. 2 is a schematic diagram showing the walking type work machine according to the first embodiment (when the inclination detection mechanism is in the second state). FIG. 5(a) is a diagram showing the case where the tilt detection mechanism is in the first state, and FIG. 5(b) is a diagram showing the case where the tilt detection mechanism is in the second state. FIGS. 6(a) and 6(b) are perspective views showing an interlocking mechanism that interlocks with the speed change lever. FIG. 6 is a diagram showing a state when the inclination detection mechanism detects the inclination (forward inclination) of the vehicle body. FIG. 8(a) is a diagram showing the case where the tilt detection mechanism according to the second embodiment is in the first state, and FIG. 8(b) is a diagram showing the case where the tilt detection mechanism according to the second embodiment is in the first state. 2 is a diagram showing a case in state 2. FIG. FIG. 7 is a diagram showing a state when the tilt detection mechanism according to the second embodiment detects the tilt (forward tilt) of the vehicle body. FIG. 10(a) is a diagram showing the case where the tilt detection mechanism according to the third embodiment is in the first state, and FIG. 10(b) is a diagram showing the case where the tilt detection mechanism according to the third embodiment is in the first state. 2 is a diagram showing a case in state 2. FIG. 11(a) and 11(b) are diagrams showing a state in which a part of the deformable portion, a switch, etc. are removed from FIG. 10(a) and FIG. 10(b). FIG. 7 is a diagram showing a state when the tilt detection mechanism according to the third embodiment detects the tilt (forward tilt) of the vehicle body.

《First embodiment》
The walk-behind work machine 100 according to the first embodiment will be described in detail below based on FIGS. 1 to 7. The walk-behind working machine 100 of the first embodiment is, for example, a walk-behind tiller (walking tractor), and is a device that automatically travels by receiving power from a motor and performs tilling work while automatically running. shall be taken as a thing.

FIG. 1 schematically shows the configuration of a walking work machine 100. In FIG. 1, the forward direction of the walk-behind work machine 100 is the +X direction, the backward direction is the -X direction, the direction perpendicular to the X-axis (left-right direction) in the horizontal plane is the Y-axis direction, and the vertical direction is the Z-axis direction. There is.

As shown in FIG. 1, the walk-behind work machine 100 includes a vehicle body 10, a working part 12 provided at the rear (-X side) of the vehicle body 10 in the traveling direction, and a drive unit provided in the vehicle body 10 extending in the Y-axis direction. An axle 14 as a shaft, a pair of wheels 16A, 16B provided at both ends of the axle 14, a handle bar 18 provided on the -X side of the vehicle body 10 and held by an operator, and a pair of wheels 16A, 16B. and a motor 20 as a drive unit that rotates the motor. Furthermore, an inclination detection mechanism 22 as a clamping pressure suppression mechanism is provided on the front side (+X side) and the lower side (-Z side) of the vehicle body 10 of the walking work machine 100.

In addition to the engine 20, the vehicle body 10 holds devices necessary for rotationally driving the wheels 16A and 16B, such as a fuel tank and a muffler.

The working unit 12 is a rotary tiller, and the tiller claws 24 rotate by receiving power from the engine 20. The working part 12 is configured to be able to be raised and lowered by the operator moving the handle rod 18 up and down around wheels 16A and 16B, and during tilling work, it is lowered to allow the tilling claws 24 to penetrate into the soil. Use it in the same condition. In addition, in the walk-behind work machine 100, for safety reasons, the tilling claws 24 are not operated during backward movement. Alternatively, when the tilling claws 24 are operating, the walking work machine 100 cannot move backward.

The wheels 16A, 16B are rotated by power supplied from the engine 20 to the axle 14 via the clutch.

The handle rod 18 is held by an operator to operate the walk-behind work machine 100. The handle rod 18 is provided with a clutch rod 26 and a handle up and down lever 28. Although not shown, the handlebar 18 is also provided with an engine switch and an accelerator lever.

The clutch rod 26 is arranged above the handle rod 18 so that it can be held together with the handle rod 18 by an operator. The clutch rod 26 is connected to the clutch via a clutch wire, and when an operator squeezes the clutch rod 26 together with the handle rod 18, the clutch wire is pulled, the clutch is connected, and power is transferred from the engine 20 to the axle 14. is transmitted (becomes a transmission state). On the other hand, when the operator releases the clutch lever 26, the clutch wire returns to its original position, the clutch is disconnected, and the transmission of power from the engine 20 to the axle 14 is interrupted (into a disconnected state). In this way, the operator can control driving/stopping of the walk-behind work machine 100 by operating the clutch lever 26.

FIG. 2(a) shows a perspective view of a section near the lower end of the handle rod 18. The handle rod 18 is rotatably provided on an adjustment base 82 provided on the vehicle body 10 via a rotating shaft 36. The angle (posture) of the handle rod 18 can be changed, for example, in three stages. More specifically, the posture (angle) of the handle rod 18 is adjusted by fitting the pin 78 integrally provided on the handle rod 18 into one of the plurality of through holes 80 provided on the adjustment base 82. is maintained. That is, in the first embodiment, the pin 78 is included to realize a function as a posture maintaining section that maintains the posture of the handle rod 18. Here, one end of the inner wire (the inner portion covered by the outer cable) of the wire 76 is connected to the pin 78, as shown in FIG. 2(a). The other end of the inner wire of the wire 76 is connected to a rotating member 72 provided on the handle rod 18, as shown in FIG. 2(b). The rotating member 72 is rotatable about a shaft 74. The other end of the inner wire of the wire 38, one end of which is connected to the handle up and down lever 28, is also connected to the rotating member 72. When the rotating member 72 is in a neutral state (none of the wires 64 and 38 are pulled) as shown in FIG. 2(b), the pin 78 is fitted into one of the plurality of through holes 80. . On the other hand, when the operator grasps the handle up and down lever 28, the inner wire of the wire 38 is pulled in the direction of the arrow I in FIG. The wire is pulled in the direction of arrow K. As a result, the pin 78 comes out of the through hole 80, making it possible to adjust the angle of the handle bar 18. In this way, the operator can easily adjust the angle of the handle rod 18 by gripping the handle up and down lever 28.

Returning to FIG. 1, a gear shift lever 30 as a switching section is provided near the handlebar 18. The operator can change the operating mode by operating the gear shift lever 30. FIG. 3 shows a display board 32 provided near the lower end of the gear shift lever 30 (on the vehicle body 10). The speed change lever 30 is movable along a groove 34 provided in the display board 32. By adjusting the position of the speed change lever 30 to each of the positions "1" to "5" shown in FIG. A "high-speed" forward mode in which the tiller claws 24 do not rotate when moving forward, a "low-speed" forward mode in which the tiller claws 24 move forward at a low speed and the tiller claws 24 do not rotate, a "reverse" mode in which the tiller moves backward and the tiller claws 24 do not rotate, and a "reverse" mode in which the tiller claws 24 move backward and the tiller claws 24 do not rotate. It is possible to change to a "cultivation" mode in which the claws 24 rotate. Note that there may be modes other than those shown in FIG. 3 as the mode.

The inclination detection mechanism 22 can be switched between a state in which it does not contact the ground (first state) as shown in FIG. 1 and a state in which it contacts the ground as shown in FIG. 4 (second state). .

The tilt detection mechanism 22 will be described in detail below.

FIG. 5(a) shows the case where the tilt detection mechanism 22 is in the first state, and FIG. 5(b) shows the case where the tilt detection mechanism 22 is in the second state. As shown in FIG. 5(a), the inclination detection mechanism 22 includes a main body portion 40 screwed to the vehicle body 10, and a deformable portion 46 attached to two fixed shafts 42 and 44 provided on the main body portion 40. , and a switch 48 as a stop section provided on the main body section 40.

The deformable portion 46 includes a wheel portion 50, a first arm portion 52 that holds the wheel portion 50, and a second arm portion 54 rotatably connected to the first arm portion 52 via a shaft 53 (see FIG. 5(b)), a third arm 56 rotatably connected to the second arm 54 via a shaft 55, and rotatably provided on the fixed shaft 44; It has a circular pressing part 57 provided at the upper end of the shaft 56 and a contact part 58 rotatably provided on the fixed shaft 44 .

A tension spring 60 is provided at the upper end (+Z end) of the third arm portion 56 to constantly apply a force in the direction of arrow A (force in a clockwise direction around the fixed shaft 44). Further, the shaft 55 is provided with a tension member 62 .

Furthermore, one end of each inner wire of the two wires 64 and 66 is connected to the deformed portion 46. Specifically, one end of the inner wire of the wire 64 is connected to the contact portion 58, and one end of the inner wire of the wire 66 is connected to the −X side end of the tension member 62.

In the first embodiment, when the wire 66 is pulled in the direction of arrow B from the state shown in FIG. 5(a) (first state), the tension member 62 moves approximately in the −X direction. As the tension member 62 moves, the shaft 55 moves approximately in the −X direction as shown in FIG. 5(b), so that the second arm portion 54 and the third arm portion 56 become approximately in a straight line. In this state, as can be seen by comparing FIGS. 5(a) and 5(b), the angle of the first arm portion 52 with respect to the X axis becomes large. Further, a pressing portion 57 provided at the upper end of the third arm portion 56 is pressed against the contact portion 58 . The state (second state) of the deformable portion 46 in FIG. 5(b) is a state in which forward tilting of the vehicle body 10 can be detected.

Here, the reason why the inner wire of the wire 66 is pulled in the direction of arrow B in FIG. ” mode position. FIGS. 6(a) and 6(b) show a perspective view of an interlocking mechanism that interlocks with the speed change lever 30. The interlocking mechanism includes a reverse gear 68 used when traveling backward. The reverse gear 68 meshes with a gear (not shown) when the state shown in FIG. 6(a) changes to the state shown in FIG. 6(b), and transmits the power necessary for backward movement of the walking work machine 100 to the axle 14.

In the interlocking mechanism, when the speed change lever 30 is in a mode other than the "reverse" mode, the reverse gear 68 is in the position shown in FIG. 6(a). When the operator operates the shift lever 30 to the "reverse" mode position, the reverse gear 68 is moved in the direction of arrow C in FIG. 6(a) by a mechanism (not shown) that is linked to the operation. As a result, when the reverse gear 68 moves to the position shown in FIG. 6(b), the reverse gear 68 pushes one end of the interlocking member 70, and the interlocking member 70 swings about the rotating shaft 71. This swinging causes the inner wire of the wire 66 connected to the interlocking member 70 to be pulled in the direction of arrow D, and in the direction of arrow B in FIG. 5(a). Note that when the operator operates the gear shift lever 30 to a position other than the "reverse" mode, the inner wire of the wire 66 returns to its original state due to the action (tensile force) of the tension spring 60, so that the deformed portion 46 is The process returns from the second state of b) to the first state of FIG. 5(a). Also, in the interlocking mechanism, since the inner wire of the wire 66 is pulled in the opposite direction to the direction of arrow D, the interlocking member 70 and the reverse gear 68 return from the state shown in FIG. 6(b) to the state shown in FIG. 6(a). . In this way, the first embodiment includes the reverse gear 68, the interlocking member 70, and the wire 66 to transition the deformable portion 46 between the first state in which it does not contact the ground and the second state in which it contacts the ground. The function as a transition section is realized.

FIG. 7 shows a state when the inclination detection mechanism 22 detects the inclination (forward inclination) of the vehicle body 10. As shown in FIG. 7, when the vehicle body 10 leans forward and the distance between the main body part 40 and the ground approaches force) acts, and the first arm portion 52 rotates counterclockwise around the fixed shaft 42 (see arrow E). In conjunction with this rotation, the third arm portion 56 rotates counterclockwise about the fixed shaft 44 against the biasing force of the tension spring 60. As a result, the pressing portion 57 rotates the contact portion 58 counterclockwise around the fixed shaft 44 (see arrow G). The state of the deforming section 46 at this time is called a "deformed state."

When the deformed portion 46 is in a deformed state in this manner, the vehicle body 10 leans forward while the walk-behind work machine 100 is moving backward, and the operator is pinched by the handle bar 18 so as to be pushed up diagonally from below. There is a high possibility that Here, pinching means that the worker is pinched between the handle bar 18 and an obstacle such as a rear wall when the walking work machine 100 is moving backward. If the pinching condition continues, a serious accident may occur. In the first embodiment, the switch 48 is pressed by the contact portion 58 when the deformation portion 46 is in the deformed state. Since the switch 48 is a kill switch that stops power supply to the spark plug of the engine 20, the engine 20 stops. As a result, the wheels 16A and 16B stop rotating, and the walking work machine 100 stops.

Further, in the deformed state, the inner wire of the wire 64 is pulled in the direction of the arrow H as the contact portion 58 rotates. Here, the other end of the inner wire of the wire 64 (the end opposite to the side connected to the contact portion 58) is attached to a rotating shaft provided on the handle rod 18, as shown in FIG. 2(b). It is connected to member 72 . As described above, the other end of the inner wire of the wire 76, which has one end connected to the pin 78, is also connected to the rotating member 72. Therefore, when the inner wire of the wire 64 is pulled in the direction of the arrow H in FIG. 7, the inner wire of the wire 64 is pulled in the direction of the arrow I in FIG. Then, the inner wire of the wire 76 is pulled in the direction of arrow K. As a result, the pin 78 in FIG. 2(a) comes out of the through hole 80, and the posture of the handle rod 18 is no longer maintained. In this way, when the posture of the handle rod 18 is not maintained, the operator can freely change the angle of the handle rod 18, so that the pressure on the operator by the handle rod 18 can be suppressed. In the first embodiment, the wire 64, the rotating member 72, the wire 76, etc. are used as a release part that removes the pin 78 from the through hole 80 and releases the state in which the handle rod 18 is maintained. functions have been realized.

In the first embodiment, when the forward tilt of the vehicle body 10 is detected by the tilt detection mechanism 22 (when the deformable portion 46 is in a deformed state), the operation of the engine 20 is stopped and the handlebar rod 18 Since the pin 78 that maintains the posture is removed from the through hole 80, even if the operator is pinched by the handle rod 18 when the walking work machine 100 is moved backwards, it is easy for the operator to take an evasive action.

As described above in detail, according to the first embodiment, the inclination detection mechanism 22 is provided in front (+X side) of the wheels 16A and 16B of the vehicle body 10, and when the vehicle body 10 is tilted forward, the inclination detection mechanism 22 is It has a deformable portion 46 that comes into contact with the surface (ground) that the wheels 16A, 16B are in contact with and changes to the deformed state shown in FIG. 7 when a predetermined force or more is applied from the ground. The switch 48 forcibly stops the rotation of the wheels 16A, 16B by the engine 20 in conjunction with the transition of the deformation section 46 to the deformed state shown in FIG. Therefore, in the first embodiment, when the vehicle body 10 is tilted forward, that is, when there is a high possibility that the operator is being squeezed by the handle bar 18 so as to be pushed up diagonally from below, the operator is forced to The engine 20 can be stopped. As a result, even if the operator is pinched between the handle bar 18 and an obstacle behind him and is unable to return the clutch bar 26, the pinch pressure can be relieved by stopping the wheels 16A and 16B. This makes it easier for the worker to escape from the situation.

Further, in the first embodiment, in conjunction with the transition of the deformable portion 46 to the deformed state shown in FIG. Since it can be pulled out, when the vehicle body 10 leans forward, the attitude maintenance of the handlebar 18 can be released. As a result, even if there is a high possibility that the worker is pushed up diagonally from below by the handle bar 18, by releasing the posture maintenance of the handle bar 18, the worker can move the handle bar 18 upward. It becomes easier to escape from between and obstacles.

Furthermore, in the first embodiment, in conjunction with the operator selecting the "reverse" mode using the gear shift lever 30, the deformable portion 46 changes from the first state shown in FIG. 5(a) to the state shown in FIG. Due to the transition to the second state b), the function of the inclination detection mechanism 22 can be exerted only when the operator is moving backwards, when there is a high possibility that the operator will be pinched by the handle bar 18. As a result, the function of the inclination detection mechanism 22 is not performed except when the vehicle is moving backwards, so that it is possible to prevent the engine 20 from stopping more than necessary or the posture maintenance of the handlebar rod 18 from being released.

In addition, in the first embodiment, the switch 48 is a kill switch that stops power supply to the spark plug included in the engine 20. It is possible to stop the rotation of the wheels 16A, 16B in response to the forward leaning of the wheel 10.

Furthermore, in the first embodiment, the portion of the deformable portion 46 that comes into contact with the ground is the wheel portion 50 . Thereby, the resistance between the deformable portion 46 and the ground can be reduced. Note that in place of the wheel portion 50, other structures (for example, ski-shaped ones) may be adopted.

In the first embodiment, the timing at which the switch 48 is pressed by the contact portion 58 and the timing at which the pin 78 comes out of the through hole 80 may be the same timing or may be different timings. . For example, the switch 48 is pressed at the timing when the deformable portion 46 is deformed as shown in FIG. 7 (the timing when the deformable portion 46 is in the first deformed state), and the first arm portion 52 is further tilted from FIG. The pin 78 may be removed from the through hole 80 (at the timing when the second deformed state is reached). Conversely, at the timing when the first arm portion 52 tilts by a predetermined amount (timing when the second deformed state is reached), the pin 78 comes out of the through hole 80, and the first arm portion 52 tilts further. The switch 48 may be pressed at the timing when the deformed state shown in FIG. 7 is reached (timing when the deformable section 46 becomes the first deformed state).

《Second embodiment》
Next, a second embodiment will be described based on FIGS. 8(a) to 9. In the second embodiment, a tilt detection mechanism 122 as shown in FIGS. 8(a) and 8(b) is employed in place of the tilt detection mechanism 22 of the first embodiment. FIG. 8(a) shows a case where the tilt detection mechanism 122 is in the first state, and FIG. 8(b) shows a case where the tilt detection mechanism 122 is in the second state.

As shown in FIG. 8(a), the tilt detection mechanism 122 includes a main body 140 screwed to the vehicle body 10, a deformable portion 146 attached to a fixed shaft 142 provided on the main body 140, and a deformable portion 146 attached to a fixed shaft 142 provided on the main body 140. A switch 148 provided in the switch 148 is provided.

The deformable part 146 is rotatably provided on the fixed shaft 142, and includes a wheel part 150, an arm part 152 that holds the wheel part 150 at one end, a torsion shaft mechanism 153 that holds the other end of the arm part 152, and It has an L-shaped member 154 to which a shaft mechanism 153 is fixed, and a contact portion 158 that is integrally provided with the arm portion 152.

As shown in FIG. 8(b), the torsion shaft mechanism 153 includes a rectangular cylindrical outer shell 250, rubber 252 provided at the four corners inside the outer shell 250, and a rectangular outer shell 252 provided inside the outer shell 250. It has a cylindrical inner shell 254. When a rotational force acts on the inner shell 254 of the torsion shaft mechanism 153, the inner shell 254 rotates within the outer shell 250 against the elastic force of the rubber 252. Then, when the force is no longer applied to the inner shell 254, the elastic force of the rubber 252 causes the inner shell 254 to return to its original state. In the second embodiment, since the arm portion 152 and the contact portion 158 are fixed to the inner shell 254, the arm portion 152 and the contact portion 158 are rotatable around the central axis of the inner shell 254. It has become. Note that as the torsion shaft mechanism 153, for example, a suspension unit DR-S manufactured by Miki Pulley Co., Ltd. can be used.

One end of the inner wire of the wire 164 is connected to the contact portion 158 . Further, one end of an inner wire of a wire 166 is connected to the L-shaped member 154. Note that, like the wire 64 in the first embodiment, the wire 164 is a wire that is pulled when the pin 78 that maintains the posture of the handle rod 18 is pulled out from the through hole 80. Further, the wire 166 is a wire that is pulled when the speed change lever 30 is positioned in the "reverse" mode, similar to the wire 66 in the first embodiment.

In the second embodiment, when the operator operates the gear shift lever 30 to the "reverse" mode position, the inner wire of the wire 166 is pulled as shown by the arrow L in FIG. The shaped member 154 rotates counterclockwise about the fixed shaft 142. As a result, the entire deformable portion 146 rotates counterclockwise about the fixed shaft 142, and transitions to the second state as shown in FIG. 8(b).

FIG. 9 shows the state of the tilt detection mechanism 122 when the vehicle body 10 is tilted (tilted forward). As shown in FIG. 9, when the vehicle body 10 leans forward and the distance between the main body part 140 and the ground approaches, a force of more than a predetermined value from the ground acts on the wheel part 150, causing the arm part 152 to twist. It rotates counterclockwise with respect to the shaft mechanism 153 (see arrow M). Due to this rotation, the contact portion 158 also rotates counterclockwise (see arrow N). The state of the deforming section 146 at this time is called a "deformed state." In such a deformed state, there is a high possibility that the operator is being squeezed by the handle bar 18 so as to be pushed diagonally upward from below. In the second embodiment, when this deformed state is reached, the switch 148 is pressed by the contact portion 158, so power supply to the spark plug of the engine 20 is stopped, and the rotation of the wheels 16A, 16B is stopped. It looks like this.

In addition, in the deformed state, the inner wire of the wire 164 is pulled by the rotation of the contact portion 158 (see arrow Q), so that the posture of the handle rod 18 is maintained by the pin 78 as in the first embodiment. It will be canceled.

In this way, also in the second embodiment, when the forward tilt of the vehicle body 10 is detected by the tilt detection mechanism 122 (when the deformable portion 146 is in the deformed state), the operation of the engine 20 is stopped. , the posture maintenance state of the handle rod 18 is released. As a result, even if the operator is pinched by the handle rod 18 when the walking work machine 100 is moved backward, it is possible to perform an avoidance action.

Note that in the second embodiment, as in the first embodiment, the timing at which the switch 148 is pressed by the contact portion 158 and the timing at which the pin 78 comes out from the through hole 80 may be the same timing. However, the timing may be different.

《Third embodiment》
Next, a third embodiment will be described based on FIGS. 10(a) to 12. In the third embodiment, a tilt detection mechanism 222 as shown in FIGS. 10(a) and 10(b) is employed in place of the tilt detection mechanism 22 of the first embodiment. FIG. 10(a) shows the case where the tilt detection mechanism 222 is in the first state, and FIG. 10(b) shows the case where the tilt detection mechanism 222 is in the second state.

As shown in FIG. 10(a), the tilt detection mechanism 222 includes a main body part 240 screwed to the vehicle body 10, a deformable part 246 attached to a fixed shaft (not shown) provided on the main body part 240, and a deformable part 246 that a switch 248 fixed to a part of the section 246. Note that FIG. 11(a) shows the deformable portion 246 (a portion other than the guide member 262a and rotating member 262b of the rotating portion 262, which will be described later), the switch 248, and the tilt detection mechanism 222 of FIG. 10(a). , shown with wire 264 removed.

As shown in FIG. 10(a), the deformable portion 246 includes a rotating portion 262 that is rotatable with respect to the main body portion 240, an arm portion 252 that is slidably provided with respect to the rotating portion 262, and an arm portion 252 that is slidable with respect to the rotating portion 262. and a wheel portion 250 provided at one end of the portion 252.

As shown in FIG. 11A, the rotating portion 262 includes a rectangular parallelepiped-shaped guide member 262a whose longitudinal direction is in the Y-axis direction, and a rotating member 262b fixed to the guide member 262a. Moreover, the rotating part 262 has a switch holding member 262c fixed to the rotating member 262b, as shown in FIG. 10(a). As shown in FIG. 11(a), the rotating member 262b is provided with respect to a rotating shaft 240a erected on the +Y side surface of the main body portion 240. Thereby, the rotating portion 262 can rotate around the Y-axis around the rotating shaft 240a. One end of the inner wire of the wire 266 is connected to a position offset from the rotation axis 240a of the rotation member 262b. Note that the outer cable of the wire 266 is fixed to a wire fixing member 241 provided on the main body portion 240, and the inner wire passes through the wire fixing member 241. Here, the wire 266 is a wire that is pulled when the speed change lever 30 is positioned in the "reverse" mode, similar to the wire 66 in the first embodiment.

A rectangular through hole 252a is formed in the arm portion 252, and a guide member 262a of the rotating portion 262 is engaged with the through hole 252a. Since the guide member 262a has a rectangular parallelepiped shape and the through hole 252a has a rectangular shape, the arm portion 252 can slide along the longitudinal direction of the through hole 252a (the X-axis direction in FIG. 10(a)). It cannot be moved or rotated in any other direction. Further, the arm portion 252 is provided with a shaft member 267 that passes through the guide member 262a, and a compression coil spring 265 is inserted through the shaft member 267. The compression coil spring 265 constantly biases the arm portion 252 in the direction away from the guide member 262a.

One end of an outer cable of a wire 264 is fixed to the arm portion 252, and one end of an inner wire of the wire 264 is connected to a guide member 262a of the rotating portion 262. Note that, like the wire 64 in the first embodiment, the wire 264 is a wire that is pulled when the pin 78 that maintains the posture of the handle rod 18 is pulled out from the through hole 80.

In the third embodiment, when the operator moves the gear shift lever 30 to the "reverse" mode position, the inner wire of the wire 266 is moved as shown by the arrow O in FIGS. 10(a) and 11(a). Since it is pulled, the rotating portion 262 rotates counterclockwise around the rotating shaft 240a. As a result, the entire deformable portion 246 rotates and transitions to the second state as shown in FIG. 10(b). FIG. 11(b) shows a state in which the configuration of FIG. 11(a) has transitioned to the second state. As shown in FIG. 11(b), in the second state, the rotating member 262b of the rotating portion 262 comes into contact with the lower surface of the wire fixing member 241, so that the rotating member 262b of the rotating portion 262 moves counterclockwise. Further rotation of the is prevented.

FIG. 12 shows the state of the tilt detection mechanism 222 when the vehicle body 10 is tilted (tilted forward). As shown in FIG. 12, when the vehicle body 10 leans forward, a force of more than a predetermined level acts on the wheel portion 250 from the ground, and the arm portion 252 moves upward against the biasing force of the compression coil spring 265 (arrow (See P). The state of the deforming section 246 at this time is called a "deformed state." In such a deformed state, there is a high possibility that the operator is being squeezed by the handle bar 18 so as to be pushed diagonally upward from below. In the third embodiment, when this deformed state is reached, the switch 248 is pressed by the arm 252, so power supply to the spark plug of the engine 20 is stopped, and the rotation of the wheels 16A and 16B is stopped. It looks like this.

In addition, in the deformed state, as the arm portion 252 moves upward, the inner wire of the wire 264 is pulled downward with respect to the outer cable. Posture maintenance state is canceled.

In this way, also in the third embodiment, when the forward tilt of the vehicle body 10 is detected by the tilt detection mechanism 222 (when the vehicle body 10 is in a deformed state), the operation of the engine 20 is stopped and the handlebar rod 18 is Since the state of maintaining the posture is released, even if the worker is pinched by the handle rod 18 when the walking work machine 100 is moved backward, it is possible to perform an avoidance operation.

Note that in the third embodiment, as in the first and second embodiments, the timing at which the switch 248 is pressed by the arm portion 252 and the timing at which the pin 78 comes out from the through hole 80 are the same timing. or at different timings.

In the first to third embodiments described above, the deformable portions 46, 146, 246 of the inclination detection mechanisms 22, 122, 222 move the vehicle body 10 only when the shift lever 30 is moved to the "reverse" mode position. Although a case has been described in which the deformation is made to a state where the inclination of the object can be detected, the present invention is not limited to this. The deformable parts 46, 146, and 246 may be in a state where they can always detect the inclination of the vehicle body 10. In this case, the wheel portions 50, 150, and 250 may be used as auxiliary wheels. Alternatively, the deformable portions 46, 146, 246 may be manually transitioned from the first state to the second state without being interlocked with the shift lever 30.

Note that in the first to third embodiments described above, a case has been described in which the power supply to the spark plug of the engine 20 is stopped when the tilt detection mechanism 22, 122, 222 detects forward tilt. It is not limited to. That is, since the inclination detection mechanisms 22, 122, 222 only need to stop the rotation of the wheels 16A, 16B, for example, the clutch between the engine 20 and the axle 14 may be disconnected, or the inclination detection mechanisms 22, 122, 222 may be used to Brakes may be applied to 16A and 16B.

In the first to third embodiments described above, when the inclination detection mechanisms 22, 122, 222 detect forward inclination, the wheels 16A, 16B are stopped and the posture maintaining state of the handlebar 18 is released. Although the case has been described above, it is not limited to this. That is, the inclination detection mechanisms 22, 122, 222 may perform only one of stopping the wheels 16A, 16B and releasing the posture maintaining state of the handlebar 18.

Note that the configurations of the tilt detection mechanisms in the first to third embodiments described above are merely examples. That is, other configurations are possible as long as the vehicle body 10 is deformed by receiving a predetermined force or more from the ground when the vehicle body 10 leans forward, and has a deformable portion that presses a switch or pulls a wire in response to the deformation. Good too.

Although the inclination detection mechanism of the first to third embodiments described above detects that the vehicle body 10 is tilted forward, it may also detect inclination in the left-right direction.

Note that in the first to third embodiments described above, the case where the walk-behind work machine is a walk-behind cultivator has been described, but the present invention is not limited to this. That is, it may be a walking type working machine other than a walking type cultivator (for example, a walking type mower, a rice transplanter, etc.).

The embodiments described above are examples of preferred implementations of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

10 Vehicle body 12 Working part 14 Axle (drive shaft)
16A, 16B Wheels 18 Handle rod 20 Engine (drive unit)
22, 122, 222 Tilt detection mechanism (pinch suppression mechanism)
30 Gear shift lever (switching part)
46, 146, 246 Deformation part 48, 148, 248 Switch (stop part)
64, 164, 264 wire (part of release part)
66, 166, 266 wire (part of transition part)
68 Reverse gear (part of transition section)
70 Interlocking member (part of transition part)
72 Rotating member (part of release part)
76 Wire (part of release part)
78 pin (posture maintenance part)
100 Walking type work equipment

Claims (6)

A vehicle body provided with a working part for performing predetermined work;
a pair of wheels that are provided on the vehicle body and rotate around a drive shaft;
a drive unit that rotates the pair of wheels;
a handle rod provided at the rear of the vehicle body in the traveling direction and gripped by an operator;
a deformable portion that is provided in front of the pair of wheels of the vehicle body and that transitions to a first deformed state by receiving a predetermined force or more from a surface in contact with the pair of wheels when the vehicle body leans forward; ,
a stop part that forcibly stops rotation of the pair of wheels by the drive part in conjunction with the transition of the deformation part to the first deformation state;
a posture maintaining section that maintains the posture of the handlebar with respect to the vehicle body;
a release unit that releases a function of the attitude maintaining unit to maintain the attitude of the handle rod in conjunction with the transition of the deforming unit to the first deformed state;
A walk-behind work machine equipped with A vehicle body provided with a working part for performing predetermined work;
a pair of wheels that are provided on the vehicle body and rotate around a drive shaft;
a drive unit that rotates the pair of wheels;
a handle rod provided at the rear of the vehicle body in the traveling direction and gripped by an operator;
a deformable portion that is provided in front of the pair of wheels of the vehicle body and that transitions to a first deformed state by receiving a predetermined force or more from a surface in contact with the pair of wheels when the vehicle body leans forward; ,
a stop part that forcibly stops rotation of the pair of wheels by the drive part in conjunction with the transition of the deformation part to the first deformation state;
a posture maintaining section that maintains the posture of the handlebar with respect to the vehicle body;
a release section that releases the function of the posture maintaining section to maintain the posture of the handle rod in conjunction with the transition of the deformation section to a second deformed state different from the first deformed state;
The second deformation state is a predetermined deformation state in which the deformation portion transitions to the first deformation state and then undergoes further force from the surface in which the pair of wheels are in contact, or a predetermined deformation state in which the deformation portion transitions to the first deformation state. a predetermined deformed state during transition to the first deformed state;
Walking type work machine. a switching unit that switches the rotation direction of the pair of wheels;
In conjunction with the switching unit switching the rotational direction of the pair of wheels to the direction in which the vehicle body moves backward, the position and/or attitude of the deformation unit is changed so that it comes into contact with the surface when the vehicle body tilts forward. a transition portion that transitions from a first state in which the surface is not in contact with the surface to a second state in which the surface is in contact with the surface;
The walking work machine according to claim 1 or 2, comprising: A vehicle body provided with a working part for performing predetermined work;
a pair of wheels that are provided on the vehicle body and rotate around a drive shaft;
a drive unit that rotates the pair of wheels;
a handle rod provided at the rear of the vehicle body in the traveling direction and gripped by an operator;
a deformable portion that is provided in front of the pair of wheels of the vehicle body and that transitions to a first deformed state by receiving a predetermined force or more from a surface in contact with the pair of wheels when the vehicle body leans forward; ,
a stop part that forcibly stops rotation of the pair of wheels by the drive part in conjunction with the transition of the deformation part to the first deformation state;
a switching unit that switches the rotation direction of the pair of wheels;
In conjunction with the switching unit switching the rotational direction of the pair of wheels to the direction in which the vehicle body moves backward, the position and/or attitude of the deformation unit is changed so that it comes into contact with the surface when the vehicle body tilts forward. a transition portion that transitions from a first state in which the surface is not in contact with the surface to a second state in which the surface is in contact with the surface;
A walk-behind work machine equipped with The drive unit is a motor,
Claim 1, wherein the stop section is a kill switch that stops power supply to a spark plug included in the engine in conjunction with the transition of the deformation section to the first deformation state. - The walk-behind work machine according to any one of 4 . Claims 1 to 4 , characterized in that the stop portion disconnects a clutch between the drive shaft and the drive portion in conjunction with the transition of the deformation portion to the first deformation state. The walk-behind work machine according to any one of the above.

Images