Walk-behind working machine

Abstract

To provide a walking type working machine which can be easily operated for backward travel and can travel backward by providing a dead man function.SOLUTION: A revolving speed adjusting device 13 of the engine 9, a transmission 11 for driving the traveling device 6 by the power of the engine 9 and switched to a forward driving state and a backward driving state by manual operation, and a clutch 10 for connecting and disconnecting power transmission to the traveling device 6 are provided. A first interlocking mechanism M1 interlocked with the speed change device 11 and the rotating speed adjusting device 13 and a second interlocking mechanism M2 interlocked with the speed change device 11 and the clutch operating part S are provided. The first interlocking mechanism M1 adjusts the rotational speed adjusting device 13 to the deceleration side in response to the speed change device 11 being switched to the reverse drive state. The second interlocking mechanism M2 changes the specifications of the clutch lever 41 provided in the clutch operator S to deadman lever specifications in response to the speed change device 11 being switched to the reverse drive state.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a walk-behind working machine. [Background technology]

[0002] As shown in Patent Document 1, there is a walk-behind work machine (walk-behind cultivation machine) equipped with a control handle extending rearward from the body, an engine, and a transmission (transmission case, gear transmission) that receives power from the engine, drives a running device (running wheels) using the input power, and can be manually switched between a forward drive state and a reverse drive state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-94027 Summary of the Invention [Problem to be solved by the invention]

[0004] In walk-behind work machines such as walk-behind cultivators, the operator holds the steering handle to steer the machine and walks along with it. When agricultural work is performed, the machine is rotated both for work and for turning. When turning, the machine may be driven in reverse. When working while moving forward, the engine is rotated at high speed to increase output, etc., which results in a high travel speed. On the other hand, when moving backward, a slower travel speed makes it easier to steer. Furthermore, if the clutch has a deadman function, the clutch disengages when the operator releases the lever during reverse, making it easier to steer, but always using the deadman lever can tire the operator's hands.

[0005] The present invention provides a walk-behind working machine that is easy to steer when moving backward. [Means for solving the problem]

[0006] The walk-behind working machine according to the present invention comprises: The vehicle is equipped with a steering handle extending rearward from the body, an engine, a manually operable rotation speed adjusting device that adjusts the rotation speed of the engine, a transmission that receives power from the engine, drives a traveling device with the input power, and is manually switched between a forward drive state and a reverse drive state, a clutch that can be switched between a clutch-on state that enables power transmission to the traveling device and a clutch-off state that cuts off the power transmission, a clutch operating unit provided on the steering handle that operates the clutch, a first interlocking mechanism interlocked with the transmission and the rotation speed adjusting device, and a second interlocking mechanism interlocked with the transmission and the clutch operating unit, the first interlocking mechanism being configured to adjust the rotation speed adjusting device to the deceleration side in response to the transmission being switched to the reverse drive state, and the second interlocking mechanism being configured to change the specifications of a clutch lever provided on the clutch operating unit to a deadman's lever in response to the transmission being switched to the reverse drive state.

[0007] With this configuration, when the transmission is switched to a reverse drive state, the first interlocking mechanism adjusts the engine speed adjustment device to the deceleration side in response to this switch, so that the engine speed when reverse is automatically set lower than when forward. Also, when the transmission is switched to a reverse drive state, the second interlocking mechanism changes the clutch lever to a deadman lever in response to this switch, so that the clutch operating section is automatically equipped with a deadman function. This realizes a walk-behind working machine that is easy to steer when reversing. Furthermore, because the deadman lever is released when the machine is not in reverse, it is also easy to steer when not in reverse.

[0008] In the present invention, It is preferable that the first interlocking mechanism is interlocked with the transmission by being interlocked with a shift lever that is manually operable on the transmission, and that the second interlocking mechanism is interlocked with the transmission by being interlocked with the shift lever.

[0009] With this configuration, the first interlocking mechanism uses the operation of the speed change lever as the operating force to operate the speed adjustment device, so there is no need for a special actuator to operate the speed adjustment device, and the second interlocking mechanism uses the operation of the speed change lever as the operating force to change the clutch lever to a deadman lever specification, so there is no need for a special actuator to change the clutch lever specification.This makes it possible to obtain a walk-behind working machine at low cost that is easy to operate when reversing and can be equipped with a deadman mechanism to enable reverse travel.

[0010] In the present invention, The speed change lever has a first swing axis, and is configured to be swung around the first swing axis as a swing fulcrum to switch the speed change device between the forward drive state and the reverse drive state, and includes a first swing link connected to the speed change lever and swung around the first swing axis as the speed change lever swings around the first swing axis as a swing fulcrum, and a second swing axis linked to the first swing link and different from the first swing axis, and the first swing link and a second swing link that is swung and operated by the swing of the first swing link, with the second swing axis as a swing fulcrum, and the first interlocking mechanism has a first operating cable that interlocks the first swing link, the second swing link, and the second swing link with the rotation speed adjustment device, and is interlocked with the speed change lever, and it is preferable that the second interlocking mechanism has a second operating cable that interlocks the first swing link, and the first swing link with the clutch operating part, and is interlocked with the speed change lever.

[0011] According to this configuration, in the first interlocking mechanism, operation of the shift lever is transmitted to the second swing link via the first swing link, and the second swing link is swung around a second swing axis different from the first swing axis as a swing fulcrum to operate the first operating cable. In the second interlocking mechanism, operation of the shift lever is transmitted to the first swing link, and the first swing link is swung around the first swing axis as a swing fulcrum to operate the second operating cable. The first operating cable is operated by the second swing link that swung around the second swing axis as a swing fulcrum, and the second operating cable is operated by the first swing link that swung around the first swing axis different from the second swing axis as a swing fulcrum, so it is easy to set different operating strokes for the first operating cable and the second operating cable. Even if the operating stroke required to change the specifications of the clutch lever differs from the operating stroke required to operate the rotation speed adjustment device, the clutch lever specifications can be changed and the rotation speed adjustment device can be operated as specified.

[0012] In the present invention, It is preferable that the first swing link has an interlocking arm portion that extends from the first swing link toward the second swing link and engages with the second swing link to interlock the first swing link and the second swing link, and that the second operating cable is connected to the first swing link by being connected to the interlocking arm portion.

[0013] According to this configuration, the first swing link and the second operating cable can be linked simply by engaging the interlocking arm portion with the second operating cable, such as by externally fitting the end of the second operating cable onto the interlocking arm portion. Therefore, compared to directly connecting the second operating cable to the first swing link, the first swing link and the second operating cable can be linked with a simpler connecting structure.

[0014] In the present invention, The clutch operating section is provided with a second clutch lever that is different from the clutch lever and is connected to the clutch via an arc link, and the second clutch lever is configured to be in a second clutch-engaged position on both sides of a dead point of the arc link and to be biased to a second clutch-disengaged position, and the clutch lever is supported together with a grip portion of the steering handle and changes position to a clutch-engaged position for operating the clutch to engage, in conjunction with the second clutch lever being positioned at the second clutch-engaged position, and the clutch lever is disengaged in conjunction with the second clutch lever being positioned at the second clutch-disengaged position. The second interlocking mechanism is configured to move away from the engaged position and change position to a clutch disengaged position where the clutch is disengaged, and the second interlocking mechanism allows movement beyond the dead point where the second clutch lever moves to one of the second clutch engaged positions on either side of the dead point that is beyond the dead point when the transmission is switched to the forward drive state, and prevents movement of the second clutch lever beyond the dead point when the transmission is switched to the reverse drive state, thereby changing the specifications of the clutch lever by the second interlocking mechanism.

[0015] With this configuration, the clutch lever needs to be positioned close to the grip of the steering handle so that it can be easily supported together with the steering handle when the specifications are changed to a deadman's lever, whereas the second clutch lever is positioned farther away from the grip of the steering handle than the clutch lever so that it can be easily operated, and when moving forward, the clutch can be easily operated with the second clutch lever.

[0016] In the present invention, It is preferable that a stopper that can be changed between a stop position in which it contacts the arc link and a stop release position in which it releases contact with the arc link is provided, and that the second interlocking mechanism allows the second clutch lever to move beyond the dead point by changing the position of the stopper to the stop release position, and prevents the second clutch lever from moving beyond the dead point by changing the position of the stopper to the stop position.

[0017] According to this configuration, even when the clutch lever and second clutch lever are interlocked, by placing the stopper in the stop position, the second clutch lever is stopped in the clutch-engaged position by the lever stopper against the bias of the second clutch lever toward the clutch-disengaged position, thereby stopping the clutch lever in the clutch-engaged position and keeping the clutch engaged, and the clutch can be operated by the second clutch lever when traveling forward. By placing the stopper in the stop-release position, the bias of the second clutch lever toward the clutch-disengaged position also biases the clutch lever toward the clutch-disengaged position, allowing the clutch lever to function as a deadman lever and enabling reverse travel with a deadman function. By interlocking the clutch lever and second clutch lever without individually interlocking the clutches, a walk-behind working machine can be obtained with a simple structure that allows clutch operation when traveling forward and reverse travel with a deadman mechanism. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a side view of the entire walk-behind cultivator from the left side. [Figure 2] FIG. 2 is a plan view showing the entire walk-behind cultivator. [Figure 3] FIG. 2 is a side view showing the main clutch and the clutch operating section. [Figure 4] FIG. 2 is a system diagram showing a power transmission system and an operating system. [Figure 5] FIG. 2 is a side view showing the gear shifting operation structure and the link mechanism. [Figure 6] FIG. 2 is a side view showing the gear shifting operation structure and the link mechanism. [Figure 7] FIG. 2 is a plan view showing the gear shifting operation structure and the link mechanism. [Figure 8] FIG. 2 is an exploded perspective view of the gear shifting mechanism and link mechanism. [Figure 9] FIG. [Figure 10] FIG. 10 is a side view of the clutch operating portion when the second clutch lever is positioned at the front second clutch engagement position. [Figure 11] 10 is a side view of the clutch operating section when the second clutch lever is in the rear second clutch engagement position and the first clutch lever is in the first clutch engagement position. FIG. [Figure 12] 10 is a side view of the clutch operating section when the second clutch lever is in the second clutch disengagement position and the first clutch lever is in the first clutch disengagement position. FIG. [Figure 13] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following describes an embodiment of a walk-behind cultivator, which is an example of a walk-behind working machine according to the present invention, with reference to the drawings. Note that the present invention is not limited to the following embodiment, and various modifications are possible within the scope of the present invention.

[0020] Unless otherwise specified, the front-to-rear and left-to-right directions in the description of this embodiment are described as follows: In other words, the forward traveling direction (the direction of arrow F in Figs. 1 and 2) when the walk-behind tiller is traveling for work is "forward," the backward traveling direction (the direction of arrow B in Figs. 1 and 2) is "rear," the direction corresponding to the left side of the forward posture in the front-to-rear direction is "left" (the direction of arrow L in Fig. 2), and similarly the direction corresponding to the right side (the direction of arrow R in Fig. 2) is "right." The left-to-right direction corresponds to the width direction of the machine body.

[0021] [Overall structure] As shown in Figures 1 and 2, the walk-behind cultivator has a body 3 composed of a transmission case 1 and an engine mounting frame 2 extending forward from the vertical middle of the transmission case 1. A control handle 4 extends rearward and upward from the top of the transmission case 1. The control handle 4 has left and right handle rods 4a. The middle parts of the left and right handle rods 4a in the fore-and-aft direction are connected by a connecting rod 4b. Axles 5 extend outward on both the left and right sides from the bottom of the transmission case 1, and tillage rotors 6 are attached to the left and right axles 5. Fenders 7 that cover the tillage rotors 6 are provided above each of the left and right tillage rotors 6. A resistance rod 8 is connected to the rear of the transmission case 1.

[0022] An engine 9 is mounted on an engine mounting frame 2. As shown in Figures 1 and 3, a main clutch 10 is provided between an output shaft 9a of the engine 9 and an input shaft 1a of a transmission case 1. A gear transmission section (not shown) is provided inside the transmission case 1. A transmission 11 is made up of the transmission case 1 and the gear transmission section.

[0023] As shown in Figure 4, the power of the engine 9 is input to the transmission 11 via the main clutch 10 and transmitted from the transmission 11 to the left and right axles 5, driving the left and right axles 5, and the left and right tillage rotors 6 are driven by the axles 5.

[0024] The transmission 11 is equipped with a shift lever 12. The shift lever 12 extends rearward from a lateral portion of the transmission case 1. The transmission 11 can be switched between a forward drive state and a reverse drive state by manually operating the shift lever 12. When switched to the forward drive state, the transmission 11 drives the axle 5 forward to drive the tillage rotor 6 forward, and when switched to the reverse drive state, the transmission 11 drives the axle 5 reverse to drive the tillage rotor 6 reverse. In this embodiment, the transmission 11 can be switched between a forward drive state with a first forward speed, a forward drive state with a second forward speed that is faster than the first forward speed, and a reverse drive state with one reverse speed.

[0025] As shown in Fig. 4, the engine 9 is provided with a rotation speed adjustment device 13. The rotation speed adjustment device 13 is adjusted to the speed-up or speed-down side by manually operating a throttle lever 14 (see Fig. 2) provided on the steering handle 4, thereby adjusting the rotation speed of the engine 9. As shown in Fig. 2, in this embodiment, the throttle lever 14 is provided near the grip portion 4c of the right handlebar 4a on the steering handle 4.

[0026] In this embodiment, as shown in Figures 1 and 3, the main clutch 10 is a belt tension clutch and has a tension arm 10a that can be swung. The main clutch 10 is switched between clutch-on and clutch-off states by swinging the tension arm 10a using a clutch operating section S provided on the steering handle 4. When switched to clutch-on, the main clutch 10 enables power transmission from the engine 9 to the transmission 11, thereby enabling power transmission to the tillage rotor 6, and when switched to clutch-off, it cuts off power transmission from the engine 9 to the transmission 11, thereby cutting off power transmission to the tillage rotor 6. The main clutch 10 is equipped with a biasing mechanism (not shown), such as a spring, that biases the tension arm 10a to swing toward the tension release side, and a disengaging biasing force is applied by the biasing mechanism.

[0027] In a walk-behind cultivator, the traveling gear is made up of left and right tillage rotors 6, which are driven by power from an engine 9 to move the machine body 3 while tilling the field. The operator holds the steering handle 4 to steer the machine body 3 and walks with the traveling machine body. The operator turns the walk-behind cultivator by steering the machine body 3 with the steering handle 4 and by operating a steering clutch (not shown) attached to the axle 5 to change the traveling direction of the machine body 3. The operator switches the transmission 11 between forward drive and reverse drive states with a speed change lever 12 to move the machine body 3 forward or backward. The operator operates the rotation speed adjuster 13 with a throttle lever 14 to increase or decrease the rotation speed of the engine 9, thereby adjusting the traveling speed of the machine body 3. The operator uses a clutch operating unit S to engage the main clutch 10 to move the machine body 3, and disengage the main clutch 10 to stop the machine body 3.

[0028] [First interlocking mechanism] As shown in Figure 4, a first interlocking mechanism M1 is interlocked with the transmission 11 and the rotation speed adjusting device 13. When the transmission 11 is switched to the reverse drive state, the rotation speed adjusting device 13 is adjusted to the deceleration side by the first interlocking mechanism M1.

[0029] More specifically, as shown in Figure 4, the first interlocking mechanism M1 includes a throttle cable 15 that interlocks the rotation speed adjuster 13 and the throttle lever 14, a link mechanism LK that interlocks with the shift lever 12 of the transmission 11, a speed control cable 16 having one end connected to the link mechanism LK, and a cable interlocking mechanism 17 that interlocks the other end of the speed control cable 16 with a location along the throttle cable 15. The first interlocking mechanism M1 is interlocked with the shift lever 12 via the link mechanism LK, and is thereby interlocked with the transmission 11. The throttle cable 15 is made up of an operating cable having an outer cable and an inner cable that passes through the outer cable. The speed control cable 16 is made up of an operating cable (see Figures 5 and 8) having an outer cable 16a and an inner cable 16b that passes through the outer cable 16a.

[0030] The speed change operation structure of the speed change device 11 is configured as shown in FIGS. That is, a lever spindle 20 protrudes laterally outward from the transmission case 1. A connecting portion 21a of a lever support member 21 is rotatably fitted onto the lever spindle 20. The lever support member 21 is swingably supported by the lever spindle 20. The lever support member 21 is provided with a lever support portion 21b located rearward of the connecting portion 21a, and a base portion 12a of the shift lever 12 is rotatably fitted into the lever support portion 21b. The shift lever 12 has a first horizontal pivot axis X of the lever spindle 20 and a second vertical pivot axis Y of the lever support portion 21b, and is supported by the transmission case 1 in a state where it can be swung in the vertical direction of the vehicle body about the first pivot axis X as a pivot point, and can also be swung in the lateral direction of the vehicle body about the second pivot axis Y as a pivot point.

[0031] A forward speed-change shaft 22 protrudes from the transmission case 1 rearward of the lever support shaft 20 so as to be able to slide laterally outward, and a forward linkage member 23 extends upward from the forward speed-change shaft 22. A forward movement operating arm 24 extends rearward from the base 12a of the speed-change lever 12, and the tip end portion of the forward movement operating arm 24 is fitted into a forward movement guide groove 23a formed in the forward movement interlocking member 23.

[0032] A reverse speed change shaft 25 protrudes from the transmission case 1 forward of the lever support shaft 20 so as to be slidable laterally outward, and a reverse interlocking member 26 protrudes rearward from the reverse speed change shaft 25. A reverse operation arm 27 extends forward from the lever support member 21, and the reverse interlocking member 26 is engaged with a reverse guide groove 27a formed at the tip of the reverse operation arm 27.

[0033] A shift guide 28 for shift lever 12 is attached to the upper part of transmission case 1. As shown in Figure 7, shift guide 28 is provided with a vertical guide groove 28a extending in the up-and-down direction of the vehicle body, a lower lateral guide groove 28b that communicates with the lower end of vertical guide groove 28a, and an upper lateral guide groove 28c that communicates with the upper end of vertical guide groove 28a.

[0034] When the speed change lever 12 is operated to swing up and down while being guided by the vertical guide groove 28a with the first swing axis X as a swing fulcrum, the forward movement operation arm 24 swings with the first swing axis X as a swing fulcrum, so that the tip of the forward movement operation arm 24 moves up and down in the forward movement guide groove 23a of the forward movement interlocking member 23, and the reverse movement operation arm 27 swings up and down with the first swing axis X as a swing fulcrum, so that the reverse movement interlocking member 26 moves up and down in the reverse movement guide groove 27a of the reverse movement operation arm 27. When the speed change lever 12 is guided by the lower lateral guide groove 28b around the second swing axis Y as a swing fulcrum and is operated to swing in the width direction of the vehicle, the forward movement operating arm 24 is also operated to swing around the second swing axis Y as a swing fulcrum, and the tip of the forward movement operating arm 24 is positioned below the forward movement guide groove 23a and presses on the lateral wall portion 23b of the forward movement interlocking member 23, and the forward movement interlocking member 23 is moved in the width direction of the vehicle by the forward movement operating arm 24. At this time, because the forward movement operating arm 24 swings relative to the lever support member 21, the reverse movement operating arm 27 is not operated and the reverse movement speed change shaft 25 is not operated.

[0035] When the shift lever 12 is operated to the left end of the lower lateral guide groove 28b, the shift lever 12 is located at the first forward gear operating position F1, the forward interlocking member 23 is moved toward the left of the vehicle by the forward operation arm 24, the forward speed-change shaft 22 is slid toward the left of the vehicle by the forward interlocking member 23, and the transmission 11 is placed in the forward drive state in first forward gear. When the shift lever 12 is operated to the right end of the lower lateral guide groove 28b, the shift lever 12 is located at the second forward gear operating position F2, the forward interlocking member 23 is moved toward the right of the vehicle by the forward operation arm 24, and the forward speed-change shaft 22 is slid toward the right of the vehicle by the forward interlocking member 23, and the transmission 11 is placed in the forward drive state in second forward gear. When the shift lever 12 is located at the first forward gear operating position F1 or the second forward gear operating position F2, it is vertically engaged by the shift guide 28 and held in the operating position F1 or F2.

[0036] When the speed change lever 12 is operated to the upper end of the vertical guide groove 28a, the reverse operation arm 27 is swung about the first swing axis X as a swing fulcrum, the reverse interlocking member 26 is moved laterally of the vehicle due to the left and right inclination of the reverse guide groove 27a, and the reverse speed change shaft 25 is slid laterally of the vehicle by the reverse interlocking member 26, and the transmission 11 is shifted to the reverse drive state. In this case, when the speed change lever 12 is swung about the second swing axis Y as a swing fulcrum and operated into the upper lateral guide groove 28c, the speed change lever 12 is positioned at the reverse operation position R1 and is locked from the up and down direction by the speed change guide 28 to be held in the reverse operation position R1. In this case, the forward operation arm 24 is swung about the second swing axis Y as a swing fulcrum. However, compared to when the speed change lever 12 is positioned in the lower lateral guide groove 28b and the tip of the forward movement operation arm 24 is positioned below the forward movement guide groove 23a, the lever support member 21 swings about the first swing axis X as a swing fulcrum, causing the forward movement operation arm 24 to swing about the first swing axis X as a swing fulcrum, moving the tip of the forward movement operation arm 24 forward and reducing its insertion into the forward movement guide groove 23a. In addition, because the tip of the forward movement operation arm 24 is formed in a tapered shape that narrows in width toward the tip, even when the forward movement operation arm 24 is swung in the lateral direction of the vehicle body about the second swing axis Y as a swing fulcrum, the tip of the forward movement operation arm 24 does not come into contact with the lateral wall portion 23b of the forward movement interlocking member 23, and the forward movement operation arm 24 does not slide the forward speed change shaft 22.

[0037] [Link mechanism] As shown in FIGS. 5, 7, 8 and 9, the link mechanism LK includes a first swing link 31 and a second swing link 32.

[0038] 7, 8, and 9, the first swing link 31 is interlocked with the speed change lever 12. The first swing link 31 is interlocked with the speed change lever 12 by attaching the first swing link 31 to the lever support member 21. The first swing link 31 is operated to swing around the first swing axis X as a swing fulcrum by the swing of the speed change lever 12 around the first swing axis X.

[0039] 7, 8, and 9, the second swing link 32 is reinforced by a first reinforcing portion 32a that is spaced apart from the second swing link 32 in the vehicle width direction, and a second reinforcing portion 32b that connects the first reinforcing portion 32a to the second swing link 32. The second swing link 32 is attached to a support member 35 via a fulcrum shaft 34 provided on the upper part of the second swing link 32, and is supported by the support member 35 in a swingable state around a link swing axis Z of the fulcrum shaft 34 as a swing fulcrum. The support member 35 is attached to the rear side of the speed change guide 28 and is held by the transmission case 1 via the speed change guide 28. The link swing axis Z is a different axis from the first swing axis X. In this embodiment, the link swing axis Z and the first swing axis X are aligned parallel to each other. The second swing link 32 is interlocked with the first swing link 31, and is operated to swing around the link swing axis Z as a swing fulcrum by the swing of the first swing link 31. The second swing link 32 is interlocked with the first swing link 31 by the fact that the first swing link 31 is provided with an interlocking arm portion 31c that extends from the free end of the first swing link 31 toward the second swing link 32, and the interlocking arm portion 31c is engaged with elongated interlocking holes 36 formed in the second swing link 32 and the first reinforcing portion 32a.

[0040] 5, 6, and 9, one end of the inner cable 16b of the speed control cable 16 is connected to the second swing link 32, and one end of the outer cable 16a of the speed control cable 16 is attached to a first outer holding member 37 rearward of the second swing link 32. The first outer holding member 37 is held by the transmission case 1.

[0041] In the link mechanism LK, when the speed change lever 12 is swung while being guided in the up-and-down guide groove 28a with the first swing axis X as its swing fulcrum, the first swing link 31 is swung by the speed change lever 12 with the first swing axis X as its swing fulcrum, and the swing of the first swing link 31 is transmitted to the second swing link 32 by the interlocking arm portion 31c, and the second swing link 32 is swung with the link swing axis Z as its swing fulcrum, and the second swing link 32 pulls and loosens the inner cable 16b. When the transmission 11 is shifted to the reverse drive state, the speed change lever 12 is operated into the upper lateral guide groove 28c, and the first swing link 31 is swung forward and the second swing link 32 is swung forward, so that the second swing link 32 pulls the inner cable 16b. When the transmission 11 is shifted to the forward drive state, the shift lever 12 is operated into the downward lateral guide groove 28b, the first swing link 31 is swung rearward, and the second swing link 32 is swung rearward, so that the second swing link 32 loosens the inner cable 16b.

[0042] [Cable interlocking mechanism] 1 and 2, the cable interlocking mechanism 17 includes an interlocking case 17a attached to the control handle 4. In this embodiment, the interlocking case 17a is attached to the right handle bar 14a of the control handle 4. The throttle cable 15 and the speed control cable 16 are interlocked inside the interlocking case 17a.

[0043] In the cable interlocking mechanism 17, when the speed control cable 16 is pulled by the second swing link 32, the throttle cable 15 is adjusted by the speed control cable 16 to the deceleration side.

[0044] In the first interlocking mechanism M1, when the transmission 11 is shifted to the reverse drive state, the first swing link 31 is swung by the operation of the shift lever 12 in this case, the second swing link 32 is swung forward by the first swing link 31, the inner cable 16b is pulled by the second swing link 32, and in the cable interlocking mechanism 17, the throttle cable 15 is operated by the tension of the speed control cable 16, and the rotation speed adjustment device 13 is adjusted to the deceleration side by the throttle cable 15.

[0045] In the first interlocking mechanism M1 of this embodiment, when the transmission 11 is shifted from a reverse drive state to a forward drive state, the engine 9 does not automatically return to the speed-up side, but the operator operates the throttle lever 14 to return the engine 9 to the speed-up side. Alternatively, the first interlocking mechanism M1 may be configured such that when the transmission 11 is shifted to the forward drive state, the rotation speed adjustment device 13 is automatically adjusted to the speed-up side, and the engine 9 is returned to the speed-up side.

[0046] [Second interlocking mechanism] As shown in Figure 4, a second interlocking mechanism M2 is interlocked with the transmission 11 and the clutch operating unit S. When the transmission 11 is switched to the reverse drive state, the first clutch lever 41 provided in the clutch operating unit S is changed to a deadman's lever by the second interlocking mechanism M2.

[0047] More specifically, as shown in Figure 4, the second interlocking mechanism M2 includes a link mechanism LK that is interlocked with the shift lever 12 that performs the gear shifting operation of the transmission 11, and a lever cable 43 that is interlocked with the link mechanism LK and the clutch operating part S. The second interlocking mechanism M2 is interlocked with the transmission 11 by being interlocked with the shift lever 12 via the link mechanism LK. The lever cable 43 is made up of an operating cable (see Figures 5 and 8) that has an outer cable 43a and an inner cable 43b that passes through the outer cable 43a.

[0048] The clutch operating section S is configured as shown in FIGS. 1 and 2, the clutch operating unit S is provided on the handlebar 4a of the steering wheel 4. In this embodiment, the clutch operating unit S is provided on the left handlebar 4a. In addition to being provided with a first clutch lever 41, the clutch operating unit S is also provided with a second clutch lever 42 that is different from the first clutch lever 41, and a lever guide 44 for the second clutch lever 42.

[0049] 10 and 13, a lever connecting portion 45 is provided at the base of the second clutch lever 42, and a second fulcrum shaft 46 is provided at the lever connecting portion 45. The second fulcrum shaft 46 is held by a clutch lever support member 47. The clutch lever support member 47 is fixed to the handlebar 4a. The second clutch lever 42 is attached to the handlebar 4a via the second fulcrum shaft 46 and the clutch lever support member 47, and is held on the steering handle 4 in a state where it can be swung back and forth around the second fulcrum axis P2 of the second fulcrum shaft 46 as a swing fulcrum, guided by the guide groove of the lever guide 44.

[0050] The lever connecting portion 45 and the rear end of the arc link 48 are connected by a link connecting pin 49. The front end of the arc link 48 and the tension arm 10a of the main clutch 10 are connected by a clutch cable 50. The second clutch lever 42 is linked to the main clutch 10 via the arc link 48 and the clutch cable 50. The clutch cable 50 is composed of an operating cable (see FIGS. 10 and 13) having an outer cable 50a and an inner cable 50b that passes through the outer cable 50a. The clutch cable 50 is linked to the arc link 48 by connecting the end of the inner cable 50b to the arc link 48 by a cable connecting pin 51 and attaching the end of the outer cable 50a to a second outer holding member 52 that is positioned forward of the arc link 48. The second outer holding member 52 is fixed to the handlebar 4a.

[0051] When the arc link 48 reaches a state in which the link connecting pin 49 overlaps the straight line [DL] (dead point line) passing through the portion of the outer cable 50a held by the second outer holding member 52 and the second fulcrum axis P2, the arc link 48 becomes a dead point that disables the swing operation of the second clutch lever 42 due to the tension of the clutch cable 50 applied by the cutting force of the main clutch 10.

[0052] 10, 11, and 12, the second clutch engagement position of the second clutch lever 42 is set at two positions, a front and a rear. In the following description, the front of the two front and a rear second clutch engagement positions is referred to as the front second clutch engagement position [INf], and the rear of the two front and a rear second clutch engagement positions is referred to as the rear second clutch engagement position [INr]. The second clutch disengagement position [OF] of the second clutch lever 42 is set rearward of the rear second clutch engagement position [INr] of the two front and a rear second clutch positions.

[0053] As shown in Figure 12, when the second clutch lever 42 is located in the second clutch disengagement position [OF], the link connecting pin 49 is located below the straight line [DL], the arc link 48 is located below the dead point, the inner cable 50b is operated to the loosening side, and the main clutch 10 is disengaged by the disengagement force of the main clutch 10.

[0054] 11 , when the second clutch lever 42 is in the rear second clutch-engaged position [INr], the link connecting pin 49 is located below the straight line [DL] and the arc link 48 is located below the dead point. However, because the link connecting pin 49 is located closer to the straight line [DL] than when the second clutch lever 42 is in the second clutch-disengaged position [OF], the inner cable 50b is pulled against the biasing force of the main clutch 10, and the main clutch 10 is engaged. In other words, the second clutch lever 42 is in the rear second clutch-engaged position [INr] below the dead point of the arc link 48 on either side of the dead point, and operates the main clutch 10 to engage. When the second clutch lever 42 is in the rear second clutch-engaged position [INr], the arc link 48 is located below the dead point, and the second clutch lever 42 is biased toward the second clutch-disengaged position [OF] by the biasing force of the main clutch 10.

[0055] 10, when the second clutch lever 42 is at the front second clutch engaging position [INf], the link connecting pin 49 is located above the straight line [DL], the arc link 48 is above the dead point, and the inner cable 50b is pulled against the biasing force of the main clutch 10, engaging the main clutch 10. In other words, the second clutch lever 42 is at the front second clutch engaging position [INf] above the dead point of the arc link 48 on either side of the dead point, and operates the main clutch 10 to engage.

[0056] When the second clutch lever 42 is positioned at the front second clutch engaging position [INf], a portion of the lever connecting portion 45 located near the link connecting pin 49 comes into contact with a lever stopper 53 provided on the clutch lever support member 47. When the second clutch lever 42 is positioned at the front second clutch engaging position [INf], the arc link 48 is above the dead point and the lever connecting portion 45 is received by the lever stopper 53, so that the second clutch lever 42 is positioned at the front second clutch engaging position [INf] by the lever stopper 53 against the biasing force of the main clutch 10. When the second clutch lever 42 is positioned at the front second clutch engaging position [INf], the second clutch lever 42 is held at the front second clutch engaging position [INf] without any operation to support the second clutch lever 42.

[0057] 10 and 13, a first fulcrum shaft 54 ​​is provided at the front end of the first clutch lever 41. The first fulcrum shaft 54 ​​is attached to the clutch lever support member 47 rearward of the second fulcrum shaft 46. The first clutch lever 41 is held by the clutch lever support member 47 in a state in which it can be pivoted around the first fulcrum axis P1 as a pivot point.

[0058] 10 and 13, the first clutch lever 41 is interlocked with the second clutch lever 42. The interlocking of the first clutch lever 41 with the second clutch lever 42 is achieved by providing an interlocking link 55 extending forward from a boss portion 41a provided on the first clutch lever 41, and an interlocking member 56 at the lever connecting portion 45 of the second clutch lever 42, which engages with an elongated interlocking hole 55a formed in the interlocking link 55. The boss portion 41a of the first clutch lever 41 is fitted onto the first fulcrum shaft 54 ​​to attach the first clutch lever 41 to the first fulcrum shaft 54. In this embodiment, the interlocking member 56 is a roller, and is attached to the lever connecting portion 45 via a roller support shaft 56a.

[0059] As shown in FIG. 11 , the first clutch lever 41 changes position to the first clutch-engaged position [IN1] in conjunction with the second clutch lever 42 being positioned at the rear second clutch-engaged position [INr]. When the first clutch lever 41 is positioned at the first clutch-engaged position [IN1], it can be supported together with the steering handle 4 and held at the first clutch-engaged position [IN1]. More specifically, a finger operating portion 41b is formed at the tip of the first clutch lever 41. When the first clutch lever 41 is positioned at the first clutch-engaged position [IN1], the finger operating portion 41b is positioned near the inside of the grip portion 4c of the left handlebar 4a. By extending the thumb of the hand supporting the grip portion 4c of the left handlebar 4a inward and contacting the finger operating portion 41b from above to support the finger operating portion 41b, the first clutch lever 41 can be supported at the first clutch-engaged position [IN1] via the second clutch lever 42 against the biasing force of the main clutch 10 associated with the first clutch lever 41.

[0060] 12, the first clutch lever 41 changes position to the first clutch disengagement position [OF1] in conjunction with the second clutch lever 42 changing position to the second clutch disengagement position [OF]. When the first clutch lever 41 is positioned at the first clutch disengagement position [OF1], it is located at a position forward of the first clutch engagement position [IN].

[0061] 10, first clutch lever 41 moves down in conjunction with the position change of second clutch lever 42 to front second clutch-engaged position [INf], and is positioned below first clutch-engaged position [IN1], and is positioned at a clutch-engaged position different from first clutch-engaged position [IN1]. In this case, finger operation portion 41b of first clutch lever 41 is positioned lower than finger operation portion 41b when first clutch lever 41 is positioned at first clutch-engaged position [IN1].

[0062] As shown in FIGS. 10 and 13 , the clutch operating unit S is provided with a stopper 60. The stopper 60 is disposed at a location overlapping the arc link 48 in a plan view. In this embodiment, the stopper 60 is formed in a round shaft shape. One end of a support link 62 is connected to an end of a stopper support shaft 61 that supports the stopper 60, and the other end of the support link 62 is connected to the second fulcrum shaft 46. The stopper 60 is attached to the clutch lever support member 47 via the stopper support shaft 61, the support link 62, and the second fulcrum shaft 46, and is held by the clutch lever support member 47 in a swingable state around the second fulcrum axis P2. The stopper 60 is supported in a swingable state between a stop position [SI] shown in FIG. 11 and a stop release position [SO] shown in FIG. 10 by swing operation. When the stopper 60 is in the stop release position [SO], the stopper spring 63 connected to the stopper spindle 61 causes the stopper spindle 61 to abut against the lower part of the clutch lever support member 47, thereby positioning the stopper 60 in the stop release position [SO].

[0063] 11, even when the position is changed to the stop position [SI], the stopper 60 allows the link connecting pin 49 to be positioned up to the front of the straight line [DP], enabling the second clutch lever 42 to be positioned at the rear second clutch position [INr]. However, when the position is changed to the stop position [SI], the link connecting pin 49 comes into contact with the arc link 48 before it passes above the straight line [DP], preventing the second clutch lever 42 from moving above the dead point of the arc link 48 and moving to the front second clutch engagement position [INf].

[0064] As shown in Figure 10, when the stopper 60 is changed to the stop release position [SO], it does not come into contact with the arc link 48 and allows the link connecting pin 49 to move upward beyond the straight line [DP], allowing the second clutch lever 42 to move upward beyond the dead point of the arc link 48 and to the front second clutch engagement position [INf].

[0065] When the stopper 60 is changed to the stop release position [SO], the second clutch lever 42 is operated to the front clutch engagement position [INf] and the main clutch 10 is held in the clutch engaged position. When the stopper 60 is changed to the stop position [SI], the first clutch lever 41 is held in the first clutch engagement position [IN1] by being supported together with the operation handle 4, and when support for the first clutch lever 41 is released, it is operated to switch to the first clutch disengagement position [OF1] by the disengagement force of the main clutch 10. In other words, when the stopper 60 is changed to the stop position [SI], the first clutch lever 41 is changed to a deadman's lever specification.

[0066] As shown in FIGS. 5, 6, and 7, one end of the outer cable 43a of the lever cable 43 is attached to the first outer holding member 37, and one end of the inner cable 43b of the lever cable 43 is connected to the first swing link 31 provided in the link mechanism LK. The inner cable 43b is connected to the first swing link 31 by connecting the inner cable 43b to an interlocking arm portion 31c provided in the first swing link 31. As shown in FIG. 7, a first arm length, which is the distance from a first swing axis X, which is the swing axis of a first connection point between the lever cable 43 and the first swing link 31, to the first connection point, is set to a length different from a second arm length, which is the distance from a link swing axis Z, which is the swing axis of a second connection point between the speed control cable 16 and the second swing link 32, to the second connection point. In this embodiment, the first arm length is set to be longer than the second arm length.

[0067] 10 and 13, the other end of the outer cable 43a of the lever cable 43 is attached to the second outer holding member 52, and the other end of the inner cable 43b of the lever cable 43 is connected to the stopper 60. The inner cable 43b is connected to the stopper 60 by connecting the inner cable 43b and the stopper support shaft 61 via a connecting spring 64.

[0068] In the second interlocking mechanism M2, when the transmission 11 is shifted to the reverse drive state, the first swing link 31 is swung forward by the operation of the shift lever 12 in this case, the inner cable 43b is pulled by the first swing link 31, and the stopper 60 is changed in position to the stop position [SI] by the tension of the lever cable 43, thereby changing the first clutch lever 41 to a deadman's lever specification.

[0069] In the second interlocking mechanism M2, when the transmission 11 is shifted to the forward drive state, the operation of the shift lever 12 in this case causes the first swing link 31 to swing rearward, and the inner cable 43b is loosened by the first swing link 31, and the stopper 60 is changed in position by the stopper spring 63 to the stop release position [SO], making it possible to operate the second clutch lever 42 to the front clutch engagement position [INf].

[0070] In this walk-behind cultivator, when the transmission 11 is shifted to the reverse drive state while the machine body 3 is traveling in reverse, in the first interlocking mechanism M1, the second swing link 32 is swung via the first swing link 31 by the operation of the shift lever 12, and the speed control cable 16 is pulled. In the cable interlocking mechanism 17, the throttle cable 15 is operated by the speed control cable 16, and the rotation speed adjuster 13 is adjusted to the deceleration side, and the first interlocking mechanism M1 automatically changes the rotation speed of the engine 9 to a speed lower than that during forward travel. Then, in the second interlocking mechanism M2, the first swing link 31 is swung by the operation of the shift lever 12, and the lever cable 43 is pulled. The position of the stopper 60 is changed to the stop position [SI] by the lever cable 43, and the first clutch lever 41 is changed to the deadman's lever position by the second interlocking mechanism M2. By supporting the first clutch lever 41 in the first clutch engaged position [IN1] with the hand supporting the control handle 4, the main clutch 10 is held in the clutch disengaged position and the machine 3 can be driven in reverse at a slower speed than when moving forward. Then, when the support of the first clutch lever 41 is released, the first clutch lever 41 is switched to the first clutch disengaged position [OF1] by the biasing force of the main clutch 10, the main clutch 10 is disengaged, and the machine 3 stops.

[0071] When the transmission 11 is shifted to the forward drive state to move the machine body 3 forward, in the second interlocking mechanism M2, the first swing link 31 is swung by the operation of the shift lever 12, the lever cable 43 is loosened, the stopper 60 is changed to the stop release position [SO] by the stopper spring 63, and the deadman lever function of the first clutch lever 41 is released. By operating the second clutch lever 42 to the front clutch engagement position [INf], the machine body 3 can be moved forward at the original forward speed while keeping the main clutch 10 engaged.

[0072] [Another embodiment] (1) In the above embodiment, the first interlocking mechanism M1 and the second interlocking mechanism M2 are interlocked with the shift lever 12, but instead, they may be interlocked with the shift operating shaft (reverse shift shaft 25) of the transmission 11, etc.

[0073] (2) In the above-described embodiment, the first swing link 31 and the second swing link 32 are provided, but the first swing link 31 and the second swing link 32 may not be provided, and the speed control cable 16 (first operating cable) and the lever cable 43 (second operating cable) may be linked to the lever support member 21, etc.

[0074] (3) In the above embodiment, the lever cable 43 (second operating cable) is connected to the interlocking arm portion 31c, but it may be connected directly to the first swing link 31.

[0075] (4) In the above-described embodiment, the second clutch lever 42, the arc link 48, and the stopper 60 are used to enable the first clutch lever 41 to be changed to a deadman's lever configuration. However, a specification change mechanism that does not include these may also be used.

[0076] (5) In the above embodiment, an example was shown in which the traveling device was constituted by the tiller rotor 6, but this is not limiting. Traveling wheels may be attached to the axle 5, and a rotary tiller may be connected to the rear of the machine body 3. In such a case where a rotary tiller is connected, it is preferable to configure the vehicle so that when the speed change lever 12 is operated to reverse, the throttle (engine) slows down and the rotary clutch is disengaged (the rotary tiller stops). It is also preferable to configure the vehicle so that when the speed change lever 12 is operated to reverse, the clutch lever is changed to a deadman's lever specification, and the rotary clutch is disengaged (the rotary tiller stops). [Industrial Applicability]

[0077] The present invention can be applied to walk-behind cultivators equipped with tilling rotors on the axles, as well as walk-behind cultivators with rotary tilling devices connected to the rear of the machine body, walk-behind rice transplanters equipped with various types of work devices other than tilling rotors or rotary tilling devices, and walk-behind vegetable transplanters. [Explanation of symbols]

[0078] 3 aircraft 4 Control Handle 9 Engine 10 Main clutch (clutch) 11 Transmission 12 Gear shift lever 13 Rotation speed control device 16 Speed ​​control cable (first operating cable) 31 First swing link 31c Interlocking arm 32 Second swing link 41 First clutch lever (clutch lever) 42 Second clutch lever 43 Lever cable (second operating cable) 48 Arc Link 60 Stopper IN1 First clutch engagement position M1 1st interlocking mechanism M2 2nd interlocking mechanism OF 2nd clutch disengagement position OF1 First clutch disengagement position S Clutch operating section SI Stop Position SO Stop release position X First swing axis Y Second oscillation axis

Claims

1. A control handle extending rearward from the aircraft; The engine and a manually operable rotation speed adjusting device for adjusting the rotation speed of the engine; a transmission that receives power from the engine, drives a traveling device using the input power, and is manually switched between a forward drive state and a reverse drive state; a clutch that can be switched between a clutch-on state that enables power transmission to the traveling device and a clutch-off state that cuts off the power transmission; a clutch operating unit provided on the steering handle for operating the clutch; a first interlocking mechanism interlocked with the transmission and the rotation speed adjusting device; a second interlocking mechanism interlocked with the transmission and the clutch operating unit, the first interlocking mechanism is configured to adjust the rotation speed adjustment device to a speed reduction side in response to the transmission being switched to the reverse drive state, The second interlocking mechanism is configured to change the specifications of the clutch lever provided in the clutch operating unit to a deadman's lever specification in response to the transmission being switched to the reverse drive state.

2. the first interlocking mechanism is interlocked with the transmission by being interlocked with a shift lever provided on the transmission in a manner that allows manual operation, 2. The walk-behind working machine according to claim 1, wherein the second interlocking mechanism is interlocked with the speed change device by being interlocked with the speed change lever.

3. the shift lever has a first pivot axis and is configured to switch the transmission between the forward drive state and the reverse drive state by being pivoted about the first pivot axis as a pivot point, a first swing link connected to the speed change lever and swung about the first swing axis as a swing fulcrum by the swing of the speed change lever about the first swing axis; and a second swing link linked to the first swing link and having a second swing axis different from the first swing axis, and swung about the second swing axis as a swing fulcrum by the swing of the first swing link, the first interlocking mechanism has the first swing link, the second swing link, and a first operating cable that interlocks the second swing link with the rotation speed adjusting device, and is interlocked with the speed change lever; 3. The walk-behind working machine according to claim 2, wherein the second interlocking mechanism has the first swing link and a second operating cable that interlocks the first swing link with the clutch operating unit, and is interlocked with the speed change lever.

4. the first swing link has an interlocking arm portion that extends from the first swing link toward the second swing link and engages with the second swing link to interlock the first swing link and the second swing link, 4. The walk-behind working machine according to claim 3, wherein the second operating cable is connected to the interlocking arm portion and thereby connected to the first swing link.

5. The clutch operating portion is provided with a second clutch lever that is different from the clutch lever and is connected to the clutch via an arc link, the second clutch lever is configured to be in a second clutch-on position on both sides of a dead point of the arc link and to be biased to a second clutch-off position, the clutch lever is configured to be supportable together with a grip portion of the steering handle and to change its position to a clutch-on position for operating the clutch to engage in cooperation with the second clutch lever being positioned at the second clutch-on position, and to move away from the clutch-on position and to change its position to a clutch-off position for operating the clutch to disengage in cooperation with the second clutch lever being positioned at the second clutch-off position, 5. The walk-behind working machine according to claim 1, wherein the second interlocking mechanism allows the second clutch lever to move beyond the dead point to one of the second clutch engagement positions on either side of the dead point, the second clutch engagement position being beyond the dead point, in response to the transmission being switched to the forward drive state, and prevents the second clutch lever from moving beyond the dead point in response to the transmission being switched to the reverse drive state, thereby changing the specifications of the clutch lever by the second interlocking mechanism.

6. a stopper whose position can be changed between a stop position in which the stopper abuts against the arc link and a stop release position in which the stopper is released from abutment against the arc link; 6. The walk-behind working machine according to claim 5, wherein the second interlocking mechanism allows the second clutch lever to move beyond the dead point by changing the position of the stopper to the stop release position, and prevents the second clutch lever from moving beyond the dead point by changing the position of the stopper to the stop position.

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