JP4105427B2 - Rear-wheel drive three-wheel management machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improved technique for a rear-wheel drive three-wheel management machine. Note that the management machine means an agricultural machine that performs management such as thinning, weeding, mowing, etc. that is carried out after seedling planting and harvesting.
[0002]
[Prior art]
As a rear wheel drive type three wheel type management machine provided with one front wheel and two rear wheels, for example, Japanese Patent Application Laid-Open No. 2001-299011 “Rear wheel drive type three wheel type management machine” (hereinafter referred to as “conventional technology”). )It has been known.
[0003]
As shown in FIG. 2 of the same publication, the above-described conventional technology includes one front wheel 26 at the front portion of the body frame 11 (the numbers are quoted in the publication, the same applies hereinafter), and the body frame. In the rear wheel drive type three-wheel management machine 10 that includes two rear wheels 31, 31 on the left and right sides at the rear of the motor 11 and drives the left and right rear wheels 31, 31 with the engine 32, the front wheel 26 is attached to the front fork 25. The front fork 25 is rotatably attached to the head pipe 21 of the body frame 11 so that the front wheel 26 can be steered by the steering handle 34.
While the three-wheeled management machine 10 is traveling in the field (between vines), the crops growing on the vines can be processed with a work tool (not shown).
[0004]
[Problems to be solved by the invention]
By the way, the ridges and ridges of the field are not always flat, and there are foreign objects such as pebbles in the ridges. When the three-wheel management machine 10 travels straight in such a place, an external force that changes the direction acts on the front wheel 26 by the front wheel 26 hitting the heel or pebbles or hitting the unevenness of the ridge. External force is transmitted from the front wheel 26 to the steering handle 34 via the front fork 25. As a result, the steering handle 34 is swung to the left and right, so that the operator needs to increase the steering force in order to maintain straight travel. Therefore, there is room for improvement to reduce the labor of the worker.
[0005]
Accordingly, an object of the present invention is to provide a technique capable of improving the straight running stability of a three-wheeled management machine having a front wheel as a free wheel.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, claim 1 is provided with one front wheel at the front of the body frame, two rear wheels on the left and right at the rear of the body frame, and a work tool for processing crops attached to the body frame. A rear-wheel drive three-wheel management machine that drives the left and right rear wheels with an engine,
In the rear-wheel drive three-wheel management machine that allows the front wheels to be steered by attaching the front wheels to the front forks and rotating the front forks to the head pipe of the fuselage frame,
A rolling plate that is provided with a cam plate having a cam groove on the head pipe or the front fork, and is attached to the front fork or the head pipe so that the base end of the swing arm can swing, and engages with the cam groove at an intermediate portion of the swing arm. And attaching the tip of the swing arm to the front fork or head pipe via an elastic member consisting of a tension spring or a compression spring and a connecting rod, so that the cam groove is formed when the front fork is directed straight. The rolling member is configured to be engaged, and the swing arm is configured to be elastically repelled by the elastic member so as to maintain the engaged state, and the connecting rod adjusts the spring force of the elastic member. It is characterized by that.
[0007]
When the front fork is directed straight, the rolling member is engaged with the cam groove, and this engaged state is maintained by the resilient member. For this reason, the direction of the front fork in the straight direction can be maintained with respect to the body frame side.
Furthermore, when an external force that changes the direction of the front wheel is transmitted from the front wheel to the front fork when the three-wheeled control machine travels straight, the cam groove and the The direction of the front fork in the straight traveling direction can be maintained until an external force that releases the engagement relationship with the rolling member is applied.
Accordingly, it is possible to suppress the front fork from fluctuating from side to side when the three-wheeled management machine travels straight ahead. For this reason, it is possible to improve the straight running stability of the three-wheel type management machine with the front wheel as a free wheel, so that the labor of the operator can be reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
Note that “front”, “rear”, “left”, “right”, “upper”, and “lower” follow the direction seen from the operator. The drawings are to be viewed in the direction of the reference numerals.
[0009]
FIG. 1 is a left side view of a rear wheel drive type three-wheel management machine according to the present invention.
The rear-wheel drive three-wheel management machine 10 includes one front wheel 26 at the front of the body frame 11, and two left and right rear wheels 31 and 31 (only the left is shown in this figure) at the rear of the body frame 11. The same applies to the following), a self-propelled working machine having an engine 32 and a seat 33 on which an operator sits at the upper rear part of the machine frame 11 and a steering handle 34 at the longitudinal center of the machine frame 11. Hereinafter, the rear-wheel drive three-wheel management machine 10 is simply referred to as “management machine 10”.
[0010]
The mounting structure of the front wheel 26 is a free wheel by providing a head pipe 21 at the front portion of the body frame 11, rotatably mounting a front fork 25 on the head pipe 21, and rotatably mounting the front wheel 26 on the front fork 25. A certain front wheel 26 can be steered.
The mounting structure of the rear wheels 31, 31 is such that the left and right rear wheel transmission mechanism cases 63a, 63a are extended downward from the rear portion of the body frame 11, and the left and right rear wheels 31 are formed below the rear wheel transmission mechanism cases 63a, 63a. 31 are rotatably mounted.
[0011]
The management machine 10 includes a work tool 40 for processing agricultural products and first, second, and third work auxiliary tools 51, 52, 52, and 53 that assist the work tool 40 in the machine body frame 11, and transmits power. A mechanism 61, a continuously variable transmission 62, rear wheel transmission mechanisms 63, 63, a forward / reverse transmission lever 71, a brake pedal 72, an operation clutch lever 73, a swing operation lever 74, and an operator step 75 are provided.
[0012]
By operating the forward / reverse shift lever 71 to switch the speed of the continuously variable transmission 62 or to switch between forward and reverse, the power of the engine 32 is transmitted to the power transmission mechanism 61, the continuously variable transmission 62, the rear wheel transmission mechanisms 63, 63. Can be transmitted to the rear wheels 31, 31 to switch the traveling speed of the rear wheels 31, 31 or to switch between forward and reverse.
[0013]
The power of the engine 32 can be transmitted to the work tool 40 by switching the power transmission mechanism 61 by switching the work clutch lever 73.
By operating the swing operation lever 74, the work tool 40 and the first, second, and third work auxiliary tools 51, 52, 52, 53 are swung up and down by a transmission hydraulic cylinder (not shown) to process the crops. Can be adjusted to the optimum height.
[0014]
The work tool 40 is for harvesting, for example, crops, and includes a work tool transmission case 41 extending forward from the rear side of the machine body frame 11 and a left-right direction from the tip of the work tool transmission case 41. An auxiliary case 42 extending horizontally, left and right working arms 43, 43 extending downward from the auxiliary case 42, left and right drive shafts 66, 66 extending from the lower ends of the work arms 43, 43, and a drive shaft It consists of left and right cutting blades 67, 67 attached to the lower end portions of 66, 66. The work tool transmission case 41 can swing up and down. 44 and 44 are auxiliary arms.
[0015]
The first work assisting tool 51 is a guide member that guides the crop just before the front wheel 26 toward the cutting blades 67 and 67 while guiding the crop so as not to get entangled with the front wheel 26. The left and right second work auxiliary tools 52, 52 are guide members that guide the farm products toward the cutting blades 67, 67 and not to get entangled with the rear wheels 31, 31. The third work auxiliary tool 53 is a guide member that guides the crop toward the cutting blades 67 and 67.
[0016]
FIG. 2 is a plan view of a rear wheel drive type three-wheel management machine according to the present invention, in which a front wheel 26 is arranged at the center of the body (center of the body width) CL, and left and right rear wheels 31, 31 and left and right of the body center CL. The left and right cutting blades 67, 67 are arranged, the seat 33 and the steering handle 34 are arranged on the left side of the machine body center CL, and the engine 32, the power transmission mechanism 61, and the work tool transmission case 41 are arranged on the right side of the machine body center CL. This shows that the power transmission switching lever 71, the brake pedal 72, the work clutch lever 73, and the swing operation lever 74 are arranged in the vicinity of the steering handle.
[0017]
FIG. 3 is a plan view of the front fork mounting structure and the steering system according to the present invention.
A more specific mounting structure of the front fork 25 is that the steering stem 22 is mounted on the head pipe 21 so as to be rotatable left and right on the steering center line St, a top bridge 23 is mounted on the upper end of the steering stem 22, and the lower end of the steering stem 22 is mounted. The bottom fork 24 is attached to the top pipe 23 and the top fork 25 is attached to the top bridge 23 and the bottom bridge 24, so that the front fork 25 is attached to the head pipe 21 so as to be rotatable left and right.
The head pipe 21 and the steering stem 22 are concentric with respect to the steering center line St, and the front fork 25 is parallel.
[0018]
According to such a steering system 20, the steering wheel 34 (see FIG. 2) steers the top bridge 23 left and right via the steering rod 27, whereby the front wheel which is a steered wheel with the steering center line St as the rotation center. 26 can be steered.
[0019]
The present invention is characterized in that the steering system 20 is provided with a straight movement maintaining mechanism 80, and the front fork 25 is maintained in a state in which the front fork 25 is directed straight by the straight movement maintaining mechanism 80.
The straight movement maintaining mechanism 80 attaches a mounting plate 81 to the head pipe 21, attaches a cam plate 82 to the mounting plate 81 with bolts 83, 83, and attaches a swing arm 85 to the bottom bridge 24 of the head pipe 21 with a support shaft 84. The base end is attached so as to be able to swing left and right, and a roller 86 is attached to an intermediate portion of the swing arm 85 so as to be rotatable left and right by a support shaft 87.
[0020]
The cam plate 82 is a semicircular member in plan view centered on the steering center line St. The cam plate 82 has a substantially V-shaped cam groove 82a at the front end of the outer peripheral surface, and on both left and right sides of the outer peripheral surface with respect to the cam groove 82a. Arc surfaces 82b and 82b are provided. The cam groove 82a is on the fuselage center CL. On the other hand, the roller 86 as the rolling member is in a position where it can engage with the cam groove 82a when the front fork 25 is directed in the straight direction shown in the drawing. In this way, the cam plate 82 can be provided on the head pipe 21, and the roller 86 can be provided on the front fork 25.
[0021]
Further, in the straight movement maintaining mechanism 80, the tip of the swing arm 85 is attached to the bracket 91 via the tension spring 88 and the connecting rod 89. The bracket 91 is a member extending rearward from the bottom bridge 24. In this manner, the front fork 25 is provided with a tension spring 88 as a spring member that springs the roller 86 toward the cam groove 82a. The connecting rod 89 serves as an adjustment bolt that adjusts the spring force of the tension spring 88.
[0022]
4 (a) and 4 (b) are operation diagrams of the straight movement maintaining mechanism according to the present invention.
(A) is a figure corresponding to the said FIG. 3, Comprising: The state which orient | assigned the front fork 25 to the straight ahead direction is shown. In this state, the roller 86 is engaged with the cam groove 82a, and the swing arm 85 is repelled rearward by the tension spring 88 in order to maintain this engaged state. Therefore, the state in which the front fork 25 is directed straight can be maintained.
[0023]
Further, when the three-wheel type management machine 10 (see FIG. 1) travels straight, if an external force that changes the direction of the front wheel 26 (see FIG. 1) is transmitted from the front wheel 26 to the front fork 25, a tensile force is applied. The direction of the front fork 25 in the straight traveling direction can be maintained until an external force that releases the engagement relationship between the cam groove 82a and the roller 86 acts against the elastic force of the spring 88.
[0024]
Therefore, it is possible to prevent the front fork 25 from wobbling left and right when the three-wheel management machine 10 travels straight. For this reason, since the straight running stability of the three-wheeled management machine 10 can be improved, the labor of the operator can be reduced.
[0025]
(B) shows that the front fork 25 is steered to the left by steering the steering handle 34 (see FIG. 2). As the bottom bridge 24 swings counterclockwise in the figure, the support shaft 84 is also displaced counterclockwise in the figure. As a result, the swing arm 85 turns counterclockwise in the figure. Along with this, the roller 86 is also displaced. When the bottom bridge 24 swings counterclockwise by an angle θ or more, the roller 86 comes off the cam groove 82a and rides on the left arc surface 82b. Thus, after the straight travel maintaining mechanism 80 is released, the front fork 25 can be freely steered.
The same applies when the front fork 25 is steered to the right.
[0026]
In the embodiment of the present invention, the straight movement maintaining mechanism 80 may be a moderation mechanism (click mechanism) having a combined structure of the cam plate 82, the rolling member 86, and the resilient member 88. Accordingly, even if the rolling member 86 is provided on the head pipe 21 and the cam plate 82 is provided on the front fork 25, the operation and effect are the same. The elastic member 88 may be provided on either the head pipe 21 or the front fork 25.
[0027]
Further, the mounting position of the cam plate 82 may be shifted backward. For example, the arc center of the cam plate 82 is shifted rearward from the steering center (rotation center of the front fork 25).
Since the arc center of the cam plate 82 is decentered rearward from the steering center, when the steering angle is further increased after the roller 86 moves off the cam groove 82a and rides on the arc surface 82b, the roller 86 has a resilient member. A force of returning to the cam groove 82a side by the elastic force of 88 works. Therefore, the straight running stability of the three-wheel management machine 10 can be further improved.
Furthermore, the rolling member 86 is not limited to a roller, and may be a ball, for example.
The elastic member 88 may be any member that elastically rolls the rolling member 86 toward the cam groove 82a, and may be, for example, a compression spring in addition to the tension spring.
[0029]
Furthermore, the management machine of the present invention is suitable for a three-wheel type management machine (agricultural work machine that performs management such as thinning, weeding, and mowing before harvesting after seedling planting), but other three-wheel agricultural machines or equivalent It can also be applied to low speed vehicles. This is because if the vehicle is a low-speed vehicle (including an agricultural machine or a transport vehicle), there is no possibility of impairing the running feeling even if the steering wheel has a click feeling.
[0030]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
In claim 1, a cam plate having a cam groove is provided on the head pipe or the front fork, the base end of the swing arm is swingably attached to the front fork or the head pipe, and the cam groove is engaged with the cam groove at an intermediate portion of the swing arm. A rolling member to be joined is provided, and the front fork is directed straightly by attaching the tip of the swing arm to the front fork or the head pipe via an elastic member made of a tension spring or a compression spring and a connecting rod. In some cases, the rolling member is configured to engage with the cam groove, and the swing arm is configured to repel the swing arm with the elastic member so as to maintain the engaged state. It is a thing to adjust.
Thus, when the front fork is directed in the straight traveling direction, the rolling member is engaged with the cam groove, and this engagement state is maintained by the elastic member. In contrast, the direction of the front fork in the straight direction can be maintained.
Furthermore, when an external force that changes the direction of the front wheel is transmitted from the front wheel to the front fork when the three-wheeled control machine travels straight, the cam groove and the The direction of the front fork in the straight traveling direction can be maintained until an external force that releases the engagement relationship with the rolling member is applied.
Accordingly, it is possible to suppress the front fork from fluctuating from side to side when the three-wheeled management machine travels straight ahead. For this reason, it is possible to improve the straight running stability of the three-wheel management machine with the front wheel as a free wheel, so that the labor of the operator can be reduced.
[Brief description of the drawings]
FIG. 1 is a left side view of a rear-wheel drive three-wheel management machine according to the present invention. FIG. 2 is a plan view of a rear-wheel drive three-wheel management machine according to the present invention. Plan view of mounting structure and steering system [FIG. 4] Action diagram of linear movement maintaining mechanism according to the present invention [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Rear-wheel drive type three-wheel type management machine, 11 ... Airframe frame, 21 ... Head pipe, 23 ... Top bridge, 24 ... Bottom bridge, 25 ... Front fork, 26 ... Front wheel, 31 ... Rear wheel, 32 ... Engine, 34 DESCRIPTION OF SYMBOLS ... Steering handle, 40 ... Working tool, 80 ... Straight running maintenance mechanism, 82 ... Cam plate, 82a ... Cam groove, 84 ... Support shaft, 85 ... Swing arm, 86 ... Rolling member (roller), 88 ... Bounce member ( Tension spring).

Claims (1)

After one front wheel at the front of the fuselage frame, two rear wheels on the left and right at the rear of the fuselage frame, a work tool for processing crops is attached to the fuselage frame, and the left and right rear wheels are driven by the engine A wheel-driven three-wheel management machine,
In the rear-wheel drive three-wheel management machine that allows the front wheels to be steered by attaching the front wheels to the front forks and rotatably attaching the front forks to the head pipe of the fuselage frame,
A cam plate having a cam groove is provided on the head pipe or the front fork,
Wherein the front fork or the head pipe, attaching the base end of the swing arm swingably,
A rolling member that engages with the cam groove is provided in an intermediate portion of the swing arm ,
By attaching the tip of the swing arm to the front fork or the head pipe via an elastic member made of a tension spring or a compression spring and a connecting rod ,
The rolling member is configured to be engaged with the cam groove when the front fork is directed in the straight direction, and the swing arm is configured to be elastically ejected by the elastic member in order to maintain the engaged state.
The connecting rod adjusts the spring force of the elastic member.
A rear-wheel drive three-wheel type management machine characterized by this.

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