JPS6346309Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a high-speed backward movement restraining structure for a walk-behind work vehicle that restricts high-speed backward movement in the direction in which the handle extends when the control handle is moved to the front side of the machine body.
Specifically, the engaged side is selectively engaged with the forward shifter shaft that can be freely changed to high and low speeds and the reverse shifter shaft that can be freely changed to high and low speeds that protrudes from the side wall of the transmission case. The shift fork is fitted into a cylindrical member that is rotatable around the horizontal axis, and the shift lever is fitted with a different diameter to the boss of the shift fork. It is configured so that it can be mated and can be slidably inserted in the direction of the axis of the boss to switch between a different diameter mating state and a different diameter unfitting state, and the orientation can be changed around the axis of the boss. The shift lever is provided with a contact member that comes into contact with the upper end of the boss portion of the shift fork to position the shift lever in a state of fitting with different diameters to the boss portion of the shift fork, and the boss of the shift fork A coil spring is fitted externally to the gear shift lever part inside the part,
The speed change lever is configured to always maintain the different diameter fitting state, and further, when the speed change lever side is changed from the normal position where the speed change lever is located at the rear of the aircraft body to the reverse orientation where the speed change lever is located at the front of the aircraft body, the speed change lever side This invention relates to a high-speed reversing restraining structure for a walk-behind work vehicle, which is configured to restrain high-speed reversing in the direction in which the gear shift lever extends by abutting a restraining member attached to the transmission case with a restraining member attached to the transmission case.

Conventionally, in the high-speed reversing restraining structure of this type of walking work vehicle, as shown in the technique described in Japanese Utility Model Application Publication No. 50-148480, the fitted state of the gear shift lever with respect to the shift fork is determined using a contact member. In addition, high-speed reversing due to the change of position of the gear lever toward the front of the aircraft is prevented by the gear change guide plate attached to the gear lever and the protrusion of the regulation plate attached to the transmission case. I was walking along.

As described above, in the past, it was common to provide separate functions for each function, such as positioning the shift lever and checking the shift lever. As described above, in a structure in which functions are separated, the positioning member and the restraining member are generally provided apart from each other in order to facilitate assembly of the shift lever with respect to the positioning member and the restraining member. Therefore,
Since the shift guide plate, which serves as a restraining member attached to the shift lever, is located far away from the rotational horizontal axis of the cylindrical member into which the shift fork is fitted, The disadvantage is that it is difficult to ensure reliable checks due to the large influence.

An object of the present invention is to reduce the influence of backlash in the rotational pivot portion of the cylindrical member by devising a restraining structure for the gear shift lever, thereby ensuring reliable restraint.

The characteristic structure of this invention to achieve the above purpose is as follows:
The restraining member attached to the speed change lever side is attached to the abutting member attached to the speed change lever, and this configuration provides the following effects.

That is, since the shift lever check member is attached to the abutment member that positions the shift lever in the fitted state with respect to the cylindrical member, there is no need to separate the abutment member and the check member. Since the check member on the mission case side that comes into contact with this check member can be placed closer to the rotation axis of the cylindrical member, the check member can be placed closer to the rotation axis of the cylindrical member. The distance to the member is shortened, making it less susceptible to the effects of backlash in the pivot portion of the cylindrical member, allowing reliable restraint. In addition, there is an advantage in that costs can be reduced by combining the positioning of the gear shift lever and the check member.Furthermore, by combining the parts, the entire device can be made smaller, so it can be placed in a small space. It is advantageous in terms of gain.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

As shown in FIG. 1, a pair of left and right running wheels 1
A drive wheel 2 for selectively attaching a tiller and a tilling rotary is supported at the lower end, and a driving unit 3 is mounted at the front.
A hitch 5 for connecting the working device is attached to the transmission transmission case 4 which is connected to the transmission case 4, and a pair of left and right operating handles 6 are attached so as to be freely rotatable to change the direction of extension forward and backward around the vertical axis P. It also constitutes a walking power tiller.

To explain the speed change operation structure of this walk-behind cultivator, as shown in Figs. A reverse shifter shaft 7a and a reverse shifter shaft 7b are provided protruding from the side wall of the transmission case 4, and the shifter 7a,
Shift members 8a and 8b attached to the protruding end of 7b
is selectively engaged with the horizontal axis _A1 by vertical swinging operation around the vertical axis A1, and in this engaged state, the vertical axis
A shift fork 9, which operates the engaged shift members 8a and 8b by a left-right swing operation around _{a 2} , is attached to a vertical shaft to a cylindrical member 10 that can swing vertically around a horizontal axis a ₁ . A base end portion of a gear shift lever ₁₂ that is integrally connected to a cylindrical member 11 constituting a boss portion of a shift fork 9 that is rotatably fitted around a core a2, and further extends to the same side as the operating handle 6. A spring 1 is attached to the center hole of the cylindrical member 11 so as to be slidable along the vertical axis _a2 between the different diameter fitting state and the different diameter unfitting state.
3, the gear lever 12 is fitted and connected in a state where it is biased toward the different diameter fitted state, and the shift lever 12 is pivoted about the horizontal axis a ₁ and vertically in the different diameter fitted state with the cylindrical member 11. The shift fork 9 is operated by swinging around the axis a ₂ , and when changing the direction of the steering handle 6 back and forth, the lever 12 is slid upward against the spring 13 to engage the cylinder member 11. With the different diameter fitting released, the lever 12 is rotated around the vertical axis _a2 , and the lever 12 is rotated again so that the lever 12 extends in the same direction as the handle 6. Cylindrical member 1
1 are fitted with different diameters, and the direction in which the gear shift lever 12 extends forward and backward can be changed.

In addition, reference numeral 14 in the figure indicates where in the hole 14a formed in the hole 14a, the end surface of the swinging end of the indicating member 15 integrally connected to the cylindrical member 11 is positioned as the lever 12 is operated to change gears. This is an indicator board for displaying the gear shift position.

The speed change operation structure is equipped with a high-speed reverse check mechanism to improve safety. To explain the structure in more detail, a mechanism is provided at the base end of the lever 12 above the different diameter fitting portion with respect to the cylindrical member 11. , an egg-shaped plate member 17 in plan view is integrally connected as an abutting member that abuts on the upper end of the cylindrical member 11 to position the lever 12 in a fitted state with respect to the cylindrical member 11;
An abutment pin member 16 is attached to the lower surface of the plate member 17 as a check member. As shown in FIG. 2A and FIG. 3, when working with the handle 6 and the gear shift lever 12 extended toward the rear of the aircraft, the gear shift operation of the lever 12 to the reverse high-speed side, that is, to the backward Shift lever 12 in extended direction
Only the operation of swinging downward around the horizontal axis _A1 and horizontally swinging inward of the body around the vertical axis _A2 is prevented by contacting with the contact pin member 16. A stopper 18a as a check member and a second
As shown in Figure 2 and Figure 3, when working with the handle 6 and the gear shift lever 12 extending forward, the lever 12 is operated to shift forward to the high speed side, that is, the gear lever 12 is extended forward. Only the operation of swinging the shift lever 12 in the extended state downward around the horizontal axis _a1 and horizontally to the outside of the aircraft around the vertical axis _a2 is performed with the contact pin member 16. The stopper 18b is a restraining member that prevents the stopper 18b from coming into contact with the stopper 18b, and the lever 12 is arranged between the pair of stoppers 18a and 18b, and the gap between the two stoppers 18a and 18b is It is integrally formed with a mounting seat 19 to the fuselage body and protrudes outward from the fuselage body with a width larger than the diameter of the lever 12 opening outward from between the parts.

In other words, by forming a gap larger than the diameter of the gear shift lever 12 between the free ends of both stoppers 18a and 18b, the lever The stopper 18a, 18b or the lever 12 can be assembled later with the lever inserted through the gap, thereby eliminating restrictions on the assembly procedure and facilitating the installation of the lever 12 and the stopper 18a, 18b. It is configured to do so.

The specific shape of the pair of stoppers 18a and 18b, which have a gap larger than the diameter of the lever 12 between their free ends, and the structure for attaching the mounting seat 19 to the fuselage body can also be changed in various ways.
Further, the shape and structure of the abutting member 16 on the lever 12 side, which prevents the lever 12 from being operated in the high-speed reverse direction by abutting against the stoppers 18a and 18b, can be modified in various ways.

The present invention is directed to high-speed reversing restraining structures for various agricultural vehicles such as power tillers, and various walking vehicles such as construction vehicles.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the high-speed reversing restraint structure for a walk-behind work vehicle according to the present invention, in which Figure 1 is an overall side view of the walk-behind cultivator, and Figures 2A and 2B show the operating state of the high-speed reverse restraint structure, respectively. FIG. 3 is a plan view of the same. 4...Mission case, 7a...Forward shifter shaft, 7b...Reverse shifter shaft, 9...Shift fork, 10...Cylindrical member, 11...Shift fork boss, 12...Traveling speed change lever for
13... Coil spring, 16... Lever side check member, 17... Contact member, 18b... Mission case side check member.

Claims (1)

[Scope of utility model registration request] a shift fork 9 selectively engages with a forward shifter shaft 7a protruding from a side wall of the transmission case 4 and operable to freely change speeds between high and low, and a reverse shifter shaft 7b protruding from a side wall of the transmission case 4 and slidingly operates the shifter shaft 7a or 7b with which it is engaged;
The shift fork 9 is fitted inside a cylindrical member 10 that is rotatable around a horizontal axis _A1 , and a speed change lever 12 is fitted inside a boss portion 11 of the shift fork 9 so as to be able to be fitted with a different diameter and to be able to slide in the axial direction of the boss portion 11 and be able to be switched between a different diameter fitted state and a different diameter fitted release state.
The gear shift lever 12 is configured to be freely changed in direction around the axis of the gear shift lever 12, and a contact member 17 that contacts the upper end of the boss portion 11 of the shift fork 9 is provided on the gear shift lever 12 to position the gear shift lever 12 in a different diameter fitted state relative to the boss portion 11 of the shift fork 9, and a coil spring 13 is fitted around the gear shift lever portion within the boss portion 11 of the shift fork 9 to constantly maintain the gear shift lever 12 in the different diameter fitted state. Furthermore, when the gear shift lever 12 is switched from a normal position in which it is located at the rear of the aircraft to a reverse position in which it is located at the front of the aircraft, a check member 16 attached to the gear shift lever 12 side and a check member 18b attached to the transmission case 4 side come into contact with each other to change the gear shift lever 12.
This high-speed reverse restraining structure for a walk-behind work vehicle is configured to restrain high-speed reverse travel in the extension direction, and is characterized in that a restraining member 16 attached to the side of the shift lever 12 is attached to a contact member 17 attached to the shift lever 12.