JP3530731B2 - Speed change device for walking type work machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift operating device for a walk-type working machine such as a management machine.

[0002]

2. Description of the Related Art Conventionally, as seen in Japanese Patent Laid-Open No. 6-174058, the two shift shafts are selectively engaged with each other by swinging about a first shaft center, and the first gear is engaged in the selective engagement state. A gear shift lever for shifting the selectively engaged shift shaft by swinging about a second axis perpendicular to the axis is provided to shift the transmission.

[0003]

However, according to the above-mentioned conventional technique, when the shift lever is swung around the first axis and the shift shaft is selected, the end portion of the shift lever is not operated due to insufficient operation amount. Is likely to engage both shift shafts together, and if the gear shift lever is swung around the second shaft core in such a state to shift gears, both shift shafts shift together and both shift gears move. Double meshing that meshes with each other may cause damage to the transmission.

An object of the present invention is to enable gear shifting without double meshing.

[0005]

The features, functions and effects of the first invention according to claim 1 are as follows.

[Characteristics] A shift lever that can be freely rocked, a shift shaft for switching between forward and backward movements, and a shift shaft for switching between elevations are provided around two shaft cores that are orthogonal to each other, and one shaft center of the shift lever is provided. A cam mechanism that shifts one shift shaft by swinging the other shift shaft is provided, and the other shift shaft is shifted by swinging around the other shaft center of the shift lever when the one shift shaft is shifted. Operate the operating arm of the shift lever
The cam mechanism is provided on the base part and
Orthogonal to the oscillating surface as it oscillates in one direction around the axis
Move relative to one direction and
As it swings in the opposite direction around the axis,
And cam followers that move relative to each other in opposite directions
By installing a cam and a cam follower.
The movement of one of the shaft cores in the axial direction is restricted.
Swing around the one shaft center together with the shift lever
Attach it to the base of the gearshift lever and attach it to the cam and cam follower.
Position the other of the two shafts in the axial direction on the one shift shaft.
It is in the point that it is attached to the state .

[Operation] According to the first aspect of the present invention, forward / backward switching or height switching is performed by shifting one shift shaft via the cam mechanism by swinging the shift lever about one shaft center. , The height change or forward / reverse switching is performed by shifting the other shift shaft through the operation arm by swinging the shift lever around the other axis in the switching state. Alternatively, since the height switching or the forward / backward switching is performed in the high / low switching state, the forward / backward switching and the height switching are performed in sequence, and there is no double meshing due to the forward / backward switching and the height switching being performed at the same time.

[0008] Then, the shift shaft with the swinging of the shift lever to the shift operation through the cam mechanism, with the swing in one direction of the shift lever to move the cam or cam follower in one direction, the shift lever Since the cam or the cam follower is moved in the opposite direction with the swing in the opposite direction, for example, the cam or the cam floor is biased in one direction by a spring, and the cam or the cam follower is moved in one direction. The movement of the cam or the cam follower is performed by the biasing force of the spring, while the movement of the cam or the cam follower in the opposite direction is performed by the operating force via the gear shift lever against the biasing force. The operating force for moving in one direction and the operating force for moving in the opposite direction can be made equal. That is, in the case of forward / reverse switching, the operating force for forward switching can be made equal to the operating force for backward switching, and in the case of high / low switching, the operating force for high-speed switching and the operating force for low-speed switching can be obtained. Can be equal

The cam has a long length in the relative swinging direction so that the inclination angle of the cam surface acting on the cam follower is loosened so that the cam and the cam follower move relatively with a small operating force. Moreover, along with this, the mounting portion is also enlarged in order to strongly support the enlarged cam action portion on the shift lever and the shift shaft. According to the first aspect of the present invention , paying attention to the above points, the cam is mounted on the gear shift lever, so that the acting portion of the cam is located far away from one shaft center to ensure the cam to the cam follower. While adopting the structure that works, there is no need to upsize the cam for that purpose. In other words, for example, when the cam is mounted on the shift shaft, a large cam follower is required when mounting the cam follower on the shift lever so that the cam follower is located far away from one shaft center. become.

[Effect] Therefore, according to the first aspect of the present invention, it is possible to perform gear shifting without double meshing and prevent damage to the transmission. or,
Opposite to the operating force in one direction of the shift shaft via the cam mechanism
Improves the feeling of shifting operation by making the operating force in the same direction
It has become possible to improve the gear shifting operability.
In addition, the cam and cam follower are prevented from increasing in size,
The body can now be made compact.

Features, operations, and features of the second invention according to claim 2
The effects are as follows.

[Features] In the feature of the first aspect of the present invention, the shift shaft for switching between forward and reverse travel is shifted through a cam mechanism as the shift lever swings about one axis, and the forward and reverse travel is performed. The shift shaft for switching between the high and low positions is configured to be shifted via the operation arm in accordance with the swinging of the shift lever around the other axis in a state where the shift shaft for switching is shifted. is there.

[Operation] In the work, the frequency of high / low switching is higher than the frequency of forward / backward switching. On the other hand, compared with the case where the shift shaft is operated to be shifted through the operation arm, the operation force required for the shift operation is larger when the shift shaft is operated through the cam mechanism. Focusing on the above point, according to the second aspect of the present invention, frequent high / low switching is performed via the operation arm, and infrequent forward / backward switching is performed via the cam mechanism. Also, the operability of switching between high and low can be improved while switching between forward and reverse.

[Effect] Therefore, according to the second aspect of the present invention, the operability of switching between high and low can be improved.

Features, operations, and features of the third invention according to claim 3
The effects are as follows.

[Characteristics] In the characteristics of the first invention and the second invention, the cam mechanism and the operation arm are installed outside a transmission case that houses a transmission operated by the shift shaft. is there.

[Operation] According to the third aspect of the present invention, the cam mechanism and the operation arm for shifting the shift shaft in accordance with the swing of the shift lever are installed outside the mission case. Maintenance of the arm can be easily performed.

[Effect] Therefore, according to the third aspect of the present invention, the maintainability can be improved.

The features, operations, and features of the fourth invention according to claim 4
The effects are as follows.

[Characteristics] In the features of the first invention, the second invention, and the third invention described above, the restraint state for preventing the shift lever from swinging to the reverse position and the swing are allowed. The reverse restraint means is provided so that it can be freely switched to the restraint release state.

[Operation] In the fourth aspect of the present invention , since the reverse-movement restraint means is switched to the restrained state to prevent the gear shift lever from swinging to the reverse-travel position, an unexpected reverse-travel is performed. Can be prevented in advance.

Further, since the reverse restraint means can be freely operated to switch to the restraint release state, if the user wants to reverse, the reverse restraint means can be switched to the restraint release state to perform the desired backward travel. .

[Effect] Therefore, according to the fourth aspect of the present invention, it is possible to surely prevent the undesired backward movement while performing the desired backward movement.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, a walk-behind work machine is configured to connect a tilling rotary 2 to the rear portion of a walk-behind self-propelled machine body 1 to carry out tilling work.

The self-propelled vehicle 1 comprises a pair of left and right traveling wheels 3
The engine 5 and the steering handle 6 for a pedestrian extending rearward are assembled to a mission case 4 having a lower part.

As shown in FIGS. 2 and 3, in the transmission case 4, a transmission having an input shaft 8a to which power is transmitted from the output shaft 5a of the engine 5 via a belt tension type clutch 7 is provided. 8 and a pair of left and right steering clutches 11 using a ball clutch for individually turning on and off transmission of power transmitted from the output shaft 8b of the transmission 8 to the left and right axles 10 via a chain type transmission 9. Is provided.

In the speed change device 8, a high / low switching shift gear 14 having a high speed transmission gear portion 12 and a low speed transmission gear portion 13 is attached to the input shaft 8a through a spline so as to be integrally rotatable and shiftable. When the high / low switching shift gear 14 is located at the high speed position, the high-speed passive gear portion 15 meshing with the high-speed transmission gear 12 and the high / low switching shift gear 1
A low-pass passive gear 17 having a low-speed passive gear portion 16 that meshes with the low-speed transmission gear 13 when 4 is in the low-speed position is axially positioned on an intermediate shaft 18 rotatably supported by the transmission case 4. Further, the forward-reverse switching shift gear 20 equipped with the transmission gear portion 19 is mounted on the intermediate shaft 18 through the spline so as to be integrally rotatable and shiftable. Transmission gear part 19
When the output shaft 8b is mounted with a passive gear 21 that meshes with the shaft shaft 8b in a state of being axially positioned and integrally rotated, and when the forward / reverse switching shift gear 20 is located in the reverse position, the transmission gear portion 19
A reverse gear 24 having a reverse passive gear portion 22 that meshes with the rear gear and a reverse transmission gear portion 23 that meshes with the passive gear 21 is rotatably mounted on the input shaft 8a in an axially positioned state. In addition, the high / low shift gear 1
A neutral position is set between the high speed position and the low speed position of No. 4 to cut off the transmission from the high / low switching shift gear 14 to the high / low switching passive gear 17, and the neutral position is set between the forward and reverse positions of the forward / reverse switching shift gear 20. the neutral position to break the transmission from the forward-reverse switching shift gears 20 to the passive gear 21 and reverse gear 24 are set.

In summary, the transmission 8 [1] shifts the high / low shift gear 14 to the low speed position and the forward / reverse shift gear 20 to the forward position to shift the low speed transmission gear part 13 to the low speed passive gear part 16 And the transmission gear portion 19 is meshed with the passive gear 21 so that the rotational power of the input shaft 8a is switched between the high and low shift gears 14 → low speed transmission gear portion 13 → low speed passive gear portion 16 → high and low switching passive gear 17
→ Intermediate shaft 18 → forward / reverse switching shift gear 20 → transmission gear part 19 → passive gear 21 → forward shaft 1 that transmits to output shaft 8b
Expressing the speed, [2] shift the high / low switching gear 14 to the high speed position and shift the forward / reverse switching shift gear 20 to the forward position to engage the high speed transmission gear portion 12 with the high speed passive gear portion 15 and transmit the same. By engaging the gear portion 19 with the passive gear 21, the rotational power of the input shaft 8a is switched between high and low shift gears 14 → high speed transmission gear portion 12 → high speed passive gear portion 15 → high and low switching passive gear 17
-> Intermediate shaft 18-> forward / reverse switching shift gear 20-> transmission gear portion 19-> passive gear 21-> forward movement 2 transmitted to output shaft 8b
Expressing the speed, [3] shift the high / low shift gear 14 to a low speed position and shift the forward / reverse shift gear 20 to a reverse position to engage the low speed transmission gear portion 13 with the low speed passive gear portion 16 and transmit the same. By engaging the gear portion 19 with the reverse drive passive gear portion 22, the rotational power of the input shaft 8a is switched between high and low shift gears 14 → low speed transmission gear portion 13 → low speed passive gear portion 16 → high and low switching passive gear 17 → intermediate shaft 18 → Forward / reverse switching shift gear 20
→ Transmission gear section 19 → Reverse passive gear section 22 → Reverse gear 2
4 → reverse transmission gear unit 23 → passive gear 21 → output shaft 8b
The reverse first speed is transmitted, and [4] the high / low switching shift gear 14 is shifted to the high speed position and the forward / reverse switching shift gear 20 is shifted to the reverse position to shift the high speed transmission gear portion 12 to the high speed passive gear portion 15. And the transmission gear unit 19 is meshed with the reverse-direction passive gear unit 22 so that the rotational power of the input shaft 8a is switched between high and low shift gears 14 → high speed transmission gear unit 12 → high speed passive gear unit 15 → high and low switching passive gears 17. → Intermediate shaft 18 → Forward / reverse switching shift gear 20
→ Transmission gear section 19 → Reverse passive gear section 22 → Reverse gear 2
4 → reverse transmission gear unit 23 → passive gear 21 → output shaft 8b
It is designed to reveal the second reverse speed.

The steering clutch 11 is energized and biased by a spring 25 so that it can be individually operated by a pair of left and right steering levers 11a attached to the steering handle 6 against the bias. ing.

The transmission 8 is attached to the tilling rotary 2.
The rotational power of the input shaft 8a is transmitted via the chain case 26 and the work clutch 27.

A device for operating the transmission 8, that is,
As shown in FIGS. 4 and 5, the shift operating device includes a shift lever 28, a shift shaft 29 for switching between forward and backward movements, a shift shaft 30 for switching between high and low, a cam mechanism 31, an operating arm 32, a shift guide means, and a reverse drive. It is equipped with tillage control means.

The gear shift lever 28 is mounted on the mission case 4 so as to be vertically swingable about the left-right axis X while being positioned outside the mission case 4.
A and an operating rod portion 28B attached to the base end portion 28A so as to be swingable right and left around a vertical axis Y that is orthogonal to the horizontal axis X. That is, the shift lever 28
Is capable of swinging up and down and swinging left and right.

The shift shaft 29 for switching between forward and backward movement is
The mission case 4 is in the left-right posture and one end in the axial direction of the mission case 4 projects outward from the mission case 4.
The shift gear 20 is mounted on the vehicle and is moved in the axial direction to change the forward / reverse switching shift gear 20 of the transmission 8 through the shift fork 29A into three positions of a forward drive position, a neutral position and a reverse drive position.

The shift shaft 30 for switching between high and low is attached to the mission case 4 in a posture in which it is in the left-right direction and one end portion of the shift shaft 30 in the axial direction thereof is projected outward from the mission case 4, and is moved in the axial direction. As a result, the high / low shift gear 14 of the transmission 8 is switched between the high speed position, the neutral position and the low speed position via the shift fork 30A.
The position is changed.

As shown in FIG. 6, the cam mechanism 31 is a mechanism for shifting the shift shaft 29 for switching between forward and backward movements as the shift lever 28 swings up and down, and the base end portion of the shift lever 28. A cam 31A is mounted on the 28A so as to swing up and down integrally therewith, and engages with a cam groove 31a formed on the cam 31A to move along the axial center of the shift shaft 29 as the cam 31A swings up and down. The cam follower 31B whose position is changed to is mounted on the shift shaft 29.
That is, as shown in FIG. 7, as the shift lever 28 swings from the forward / rearward neutral position N1 to the forward drive position F, the cam 31A presses the cam follower 31B to move the shift shaft 29 from the neutral position to the forward drive position. As the shift lever 28 swings from the forward drive position F to the forward / backward neutral position N1, the cam follower 31B is pressed by the cam 31A to move the shift shaft 29 from the forward drive position to the neutral position, and the forward / backward neutral drive of the shift lever 28 is performed. With the swing from the position N1 to the reverse position R, the cam follower 31B is pressed by the cam 31A to move the shift shaft 29 from the neutral position to the reverse position, and the shift lever 28 moves from the reverse position R to the forward / reverse neutral position N1. With the swing, the cam follower 31B is pressed by the cam 31A to move the shift shaft 29 from the reverse position to the neutral position.

The operating arm 32 shifts the shift shaft 30 for switching between high and low in accordance with the lateral swing of the shift lever 28, and the engaging tool 3 attached to the shift shaft 30.
The shift shaft 30 is moved by swinging to the left and right integrally with the operating rod portion 28B of the shift lever 28 in the state of being engaged with 3. That is, as shown in FIG. 7, the shift shaft 30 is moved between the neutral position and the high speed position as the shift lever 28 swings between the high and low neutral position N2 and the high speed position H, and the shift lever 28 moves. The shift shaft 30 is moved between the neutral position and the low speed position in accordance with the swing between the high and low neutral position N2 and the low speed position L.

The shift guide means is means for restricting the swing of the shift lever 28 by inserting the shift lever 28 into the guide groove 34A formed in the shift guide plate 34, and FIG.
As shown in FIG. 7, the guide groove 34A is provided only when the speed change lever 28 is located at the high / low neutral position N2.
Of the forward and backward guide grooves 34a that allow the rocking between the forward drive position F and the reverse drive position R, and the low speed position L of the speed change lever 28 only when the speed change lever 28 is in the forward drive position F,
That is, only when the first forward speed guide groove portion 34b that allows movement to the first forward speed position F1 and the speed change lever 28 are located at the forward speed position F, the high speed position H of the speed change lever 28, that is, the second speed forward speed position. The second forward speed guide groove portion 34c that allows the movement to F2 and the low speed position L of the speed change lever 28 only when the speed change lever 28 is positioned at the reverse speed position R, that is,
It has a reverse first speed guide groove portion 34d that allows movement to the reverse first speed position R1. That is, the transmission 8 itself is
Although it is possible to perform two forward and two reverse shifts, the shift guide means restricts the forward two shifts and the reverse one shift, so that high speed reverse cannot be performed.

The reverse cultivating and restraining means prevents the cultivating work in the reverse state, that is, the work clutch 27 is engaged and the work clutch 27 is engaged while the transmission 8 is operated in the reverse direction. As a means for restraining the reverse operation of the transmission 8 in the state, as shown in FIGS. 1, 5 and 7, the operation lever 35 of the working clutch 27 moves from the clutch engaged position P1 to the clutch disengaged position P2. A swing arm 36 that reversibly swings from the front position to the rear position in response to swing is provided, and a check rod 37 that penetrates the shift guide plate 34 in the front-rear direction is attached to the upper end of the swing arm 36. A check plate 38 acting on the check rod 37 is attached to the check plate 28. The check plate 38
When the shift lever 28 is located at the forward position F, the end of the check rod 37 is penetrated to allow the check rod 37 to move between the front position pf and the rear position pr, whereby the operation lever 35 moves. In addition to having a hole 38a that allows rocking between the clutch engaged position P1 and the clutch disengaged position P2, avoiding contact with the check rod 37 when the check rod 37 is located at the rear position pr. The shift lever 28 is allowed to swing, and the check rod 3
7 penetrates the hole 38a and is located at the front position pf,
When the shift lever 28 is in the reverse position R, it contacts the front end of the check rod 37 when the shift lever 28 is positioned in the reverse position R, and contacts the check rod 37 at the periphery of the hole 38a to prevent the shift lever 28 from swinging to the reverse position R. The rod 37 is prevented from moving to the front position pf, that is, the restraining rod 37 is held at the rear position pr.

[Other Embodiments] In the above embodiment, the backward cultivating and restraining means is omitted,
The reverse restraint means is separately provided. That is, as shown in FIGS. 8 and 9, the operating rod portion 28 of the shift lever 28 is
B is configured to be extendable / contractible at the root portion, a spring 39 for urging and extending the operating rod portion 28B is provided, and a stopper 40 is provided on the back surface of the speed change guide plate 34, and the stopper is provided when the operating rod portion 28B is in the extended state. 40 to prevent the shift lever 28 from moving from the forward drive position F to the reverse drive position R, while avoiding the shift lever 28 from contacting with the stopper 40 when the operating rod 28B is in the shortened state. A contact 41 for allowing the movement from the forward drive position F to the reverse drive position R is attached to the operating rod portion 28B so that the reverse position R of the speed change lever 28 is increased.
A reverse restraint means configured to be freely switchable between a restraint state in which the swinging to a stop is allowed and a restraint release state in which the swing is permitted, and biased to the restraint state. The surface of the stopper 40, which comes into contact with the abutment 41 as the speed change lever 28 swings from the backward position R to the forward position F, presses the abutment 41 as the abutment 41 moves to shorten the operating rod portion 28B. The contact 41 is allowed to pass over the stopper 40, that is, the cam surface 42 is formed so as to swing from the reverse position R to the forward position F of the speed change lever 28 without further reducing the speed change lever 28. Has been done. The shift guide plate 34
To the high speed reverse position of the shift lever 28, that is, the reverse 2
Reverse second speed guide groove 34e that allows movement to the speed position R2
Are formed. That is, in this other embodiment, the shift is performed in two forward gears and two reverse gears. Also,
In this other embodiment, since the restraint state is urged,
In order to cancel the restraint, it is necessary to be aware of it without fail, and it is easy to ensure the restraint.

In the above embodiment, the forward / backward switching is performed by vertically swinging the speed change lever 28, and the high / low switching is performed by horizontally swinging the speed change lever 28. However, the high / low switching is performed by vertically swinging the speed change lever 28. Then, the forward / backward movement may be switched by swinging the shift lever 28 to the left or right.

In the above-described embodiment, the reverse travel restraint means shown in the above-mentioned other embodiment is provided and implemented.

In the above embodiment, the reverse cultivating and restraining means is provided, but the reverse cultivating and restraining means may be omitted.

In the above embodiment, the walking type working machine in which the tilling rotary 2 is connected to the self-propelled machine body 1, that is, the walking type tiller is shown, but the present invention connects the working devices other than the tilling rotary 2 to each other. It can also be applied to walk-behind work machines.
Further, the present invention can be applied to a walk-behind work machine in which the rotary work device is mounted on the axle 10 instead of the traveling wheels 3.

In the above embodiment, the shift shaft 29 for switching between forward and backward movements is shifted by the swing of the shift lever 28 via the cam mechanism 31, and the shift lever 28 is swung by the operating arm 32. Shift shaft 30 for switching between high and low
The shift operation is performed by shifting the shift shaft 30 for changing the height with the swing of the speed change lever 28 via the cam mechanism 31, and with the swing of the speed change lever 28 via the operation arm 32. The shift shaft 29 for switching the forward movement may be operated by shifting.

In the above embodiment, in the cam mechanism 31, the cam 31A is mounted on the speed change lever 28 and the cam follower 31B is mounted on the shift shaft.
With the cam follower 31B as the shift lever.
The cam mechanism 31 may be mounted on the.

[Brief description of drawings]

FIG. 1 Side view of a walk-behind work machine

FIG. 2 is a vertical cross-sectional view of the main part inside the mission case.

FIG. 3 is a vertical cross-sectional view of the main part inside the mission case.

FIG. 4 is a cutaway side view showing the arrangement of shift shafts in a mission case.

FIG. 5 is a cutaway side view of the gear shift operating device.

FIG. 6 is a front view of a cam mechanism.

FIG. 7 is a rear view of the shift guide plate.

FIG. 8 is a cutaway side view of the gear shift operating device according to another embodiment.

FIG. 9 is a rear view of a shift guide plate showing another embodiment.

[Explanation of symbols]

4 mission case 8 gearbox 28 gear shift lever 29 shift axis 30 shift axis 31 Cam mechanism 31A cam 31B cam follower 32 Operation arm X axis core Y axis core R reverse position

Continuation of the front page (56) References JP-A-9-109717 (JP, A) JP-A-60-191823 (JP, A) JP-A-8-188063 (JP, A) JP-A-6-174058 (JP , A) JP-A-8-253046 (JP, A) Fukukaihei 4-50756 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 20/00-20/08 F16H 59/00-63/48

Claims (4)

(57) [Claims] 1. Two axial cores (X) (Y) orthogonal to each other
A shift lever (28) that can be freely rocked, a shift shaft (29) for switching between forward and backward movements, and a shift shaft (30) for switching between elevations are provided around the shift lever (28), and one axis (X) of the shift lever (28) is provided. ) A cam mechanism (31) for shifting one of the shift shafts (29) by swinging around is provided, and the other one of the speed change levers (28) in the state where the one shift shaft (29) is shifted. An operation arm (32) for shifting the other shift shaft (30) by swinging around the axis (Y).
Is provided at the base of the speed change lever (28), and the cam mechanism is provided.
As (31), one axis of the speed change lever (28)
(X) Directly swings around the swinging surface as it swings in one direction.
And the gear lever (2
8) Along with swinging in the opposite direction around one axis (X)
Cams that move relative to each other in the opposite direction orthogonal to the swinging surface
(31A) and cam follower (31B)
Is provided, and the cam (31A) and the cam follower (31
One of (B) B (31A) of the one axis (X)
Movement in the axial direction is restricted and is integrated with the speed change lever (28).
Shift lever so that it swings around the one axis (X)
Attached to the base of the cam, the cam (31A) and the cam follower
Shift the other (31B) of (31B) to the one
A shift operating device for a walk- behind work machine, which is mounted on a shaft (29) in a state of being axially positioned . 2. The shift shaft (29) for switching between forward and backward movements is shifted through a cam mechanism (31) with the swing of the speed change lever (28) around one axis (X). When the shift shaft (29) for switching between forward and reverse is shifted, the gear shift lever (28) is swung around the other axis (Y), and the height of the shift lever (28) is switched via the operation arm (32). The shift operating device for a walk-behind work machine according to claim 1, wherein the shift shaft (30) is configured to perform a shift operation. 3. The cam mechanism (31) and the operation arm (32) are installed outside a mission case (4) containing a transmission (8) operated by the shift shaft. A shift operating device for the walk-behind work machine described. Wherein said shift lever (28) according to claim restraining state and rocking to prevent swinging of the reverse position is provided with operating freely backward restraining means switchable between restraint released state to allow 1-3 5. A shift operating device for a walk-behind work machine according to any one of 1.