JPH0338969Y2 - - Google Patents

Description

[Detailed description of the invention] In the present invention, a rotary tilling device equipped with a tilling rear cover that can freely swing up and down as the tilling depth changes is connected to the traveling machine via a hydraulic actuator so that it can be driven up and down. In addition, a mechanical linkage mechanism is provided that operates and controls the control valve of the hydraulic actuator in conjunction with the vertical rocking displacement of the rear tilling cover so that the tilling depth of the rotary tilling device is maintained within a set range. This invention relates to a tillage depth control device for a power tiller.

In the tilling depth control device described above, if the tilling rear cover of the rotary tilling device is configured to be able to swing upwardly above the tilling depth control range, when the tilling rear cover comes into contact with an obstacle, it will smoothly escape and swing, causing damage. However, for example, when the tilling rear cover of the tilling device that is lowered at the end of the rotation at the end of the field comes into contact with the ridge, especially when the tilling depth is set to be shallow, the tilling rear cover may As a result, the large operating force associated with the upward swing of the tiller rear cover acts on the control valve and mechanical linkage mechanism that have reached the stroke end. There were problems that led to deformation and damage.

Therefore, as a means to improve such problems, as shown in Japanese Utility Model Application Publication No. 58-18410, a pair of left and right rockers that are provided with a ball detent mechanism in the mechanical interlocking mechanism are provided that are capable of relative rocking. Set up a board,
It may be possible to prevent the operating force associated with the rocking of the rear tilling cover from exerting strain on the control valve or mechanical linkage mechanism that has reached the stroke end, but in such a case, the mechanical linkage mechanism Additionally, it is necessary to separately provide a pair of left and right rocking plates equipped with a control release mechanism, that is, a ball detent mechanism, which is disadvantageous in that it increases the cost and complicates the structure of the mechanical linkage mechanism.

The present invention aims to solve the above-mentioned drawbacks while simplifying the structure of the release mechanism.

A characteristic configuration of the tilling depth control device for a tiller according to the present invention, which was taken to achieve such an object, is that when the control valve reaches the stroke end during the mechanical linkage mechanism, the tilling depth control device further controls the rear tilling cover. A cam mechanism is provided in contact with the plowing depth setting lever to allow the upward swinging of the cover while restricting the operating force associated with the swinging displacement of the cover from being transmitted to the control valve side. It is in the point where it is.

The functions and effects of the above characteristic configuration are as follows.

<Function> Until the control valve reaches the stroke end, the rocking displacement of the tiller rear cover is transmitted to the control valve, but after the control valve reaches the stroke end, the The cam mechanism can reliably prevent unreasonable operating force from acting on the control valve due to the rocking displacement of the rear tilling cover.

<Effects> Since the cam mechanism that comes into contact with the tilling depth setting lever is provided in this way, the tilling depth setting lever can be used as a part of the release machine, which simplifies the structure of the release mechanism and reduces costs. It is possible to reduce the cost.

By using the plowing depth setting lever as part of the release mechanism, the release mechanism is incorporated into the mechanical linkage mechanism, but the structure of the linkage mechanism can be simplified.

Hereinafter, embodiments of the configuration of the present invention will be described based on the drawings.

The riding-type cultivator shown in FIGS. 1 and 2 comprises a single-acting hydraulic cylinder 1 as an example of a hydraulic actuator, and a pair of left and right lift arms that are driven and oscillated up and down by the hydraulic cylinder 1. 2,
A rotary tilling device B is connected to the rear of the traveling body A equipped with a lift arm 2 via a top link 3 and a pair of left and right lower links 4, 4 so as to be able to rise and fall, and the lift arms 2 and the lower link 4, 4 are connected via lift rods 6, 6,
Thus, the rotary tiller B is configured to be movable up and down with respect to the traveling machine A by the hydraulic cylinder 1.

The hydraulic cylinder 1 is provided in a cover case 8 attached to the upper part of the transmission case 7, and a control valve 9 for the hydraulic cylinder 1 is attached to the lower part of the cover case 8.

The tilling device B includes a tilling rear cover 12 whose lower end is in contact with the rear end of an upper tilling cover 11 that covers the upper side of the rotation trajectory of the tilling claws of the tilling device main body 10.
The tilling rear cover 12 is pivotably connected to be swingable up and down around the horizontal axis _X1 as the tilling depth changes, and the tilling rear cover ₁₂ is connected so as to be bendable around the horizontal axis X2. Upper and lower divided cover members 12a, 12
It is composed of b. Of these two divided cover members 12a, 12b, the upper cover member 12a
The upper cover member 12b is urged to swing downwardly via a spring 13 with respect to the upper tilling cover 11, and the lower cover member 12b is urged to swing downwardly via a spring 14 with respect to the upper cover member 12a. has been done.

As shown in FIG. 3, a spool operating arm 15 is pivotally connected to the end of the spool 9a of the control valve 9 so as to be rotatable around a vertical axis,
Of a lever shaft 16 and an operating shaft 17 that are connected to both ends of the operating arm 15 so as to be rotatable around a horizontal axis, one of the operating shafts 17 and the tilling rear cover 12 of the tilling device B are connected. The control valve 9 is operated and controlled in conjunction with the vertical rocking displacement of the tilling rear cover 12 so that the tilling depth of the tilling device B is maintained at the tilling depth value set by the tilling depth setting lever 18. A mechanical linkage mechanism 19 is provided.

On the other hand, the lever shaft 16 and one lift arm 2 corresponding thereto are connected to a feedback rod 20.
A position lever 21 provided on the operating shaft 17 is linked to the tilling depth setting lever 18 or the tilling rear cover 12, and as the operating shaft 17 rotates, the hydraulic cylinder 1 is operated. As the lift arm 2 is raised and lowered, the lever shaft 16 is rotated to the neutral return side of the control valve 9, and a feedback control mechanism is provided which stops the tilling device B from raising and lowering at a height corresponding to each rotational phase of the operating shaft 17. It consists of

The mechanical linkage mechanism 19 is constructed as follows.

The bracket 22 and the upper cover member 12 are fixed to the lower cover member 12b of the tiller rear cover 12.
The upper and lower intermediate portions of the first swing link 24 pivotally connected to the bracket 23 of a are interlocked and connected via the rod 25, and the upper end of this first swing link 24 and the bracket 26 of the top tilling cover 12a are connected together. The upper end of the second swing link 27 is pivotally connected to the upper end of the second swing link 27 via a rod 28.

Further, as shown in FIGS. 4 and 5, a mounting member 31 including a support shaft 29 and a cylindrical body 30, which are positioned parallel to the operation shaft 17, is fixed to the mission case 7. A V-shaped receiving portion 34a for the inner wire 33a end of the push-pull wire 33 connected to the second swing link 27 is provided at one end of the rotation support shaft 32 rotatably inserted and held in the cylindrical body 30. A plate-shaped cam 35 is fixed to the other end of the rotary support shaft 32.

The plowing depth setting lever 1 is attached to the fixed support shaft 29.
A cylindrical shaft 36 having a diameter of 8 is rotatably fitted on the outside, and a disc spring 37 is interposed between the cylindrical shaft 36 and the mounting member 31 to frictionally hold the tillage depth setting lever 18 at any operating position. are doing.

The arm 38 fixed to the cylinder shaft 36 has a V-shaped cam follower 3 that comes into contact with the cam 35.
9 is pivotally mounted, the cam follower 39 and the operating shaft 17 are interlocked and connected via a rod 40, and further,
A spring 41 is provided which urges the spool 9a of the control valve 9 to move downward via the operating shaft 17 and the operating arm 15.

Then, when the tilling depth of the tilling device B becomes shallower than the tilling depth value set by the tilling depth setting lever 18 and the tilling rear cover 12 swings downward, the inner wire 33a of the push-pull wire 33
is pulled, and the operating shaft 17 is rotated by the elastic biasing force of the spring 41 until the end of the inner wire 33a and the V-shaped receiving portion 34a of the arm 34 come into contact with each other, and the control valve 9 is lowered. It is switched and the tilling device B is driven down. Due to the operation of the feedback rod 20 and push-pull wire 33 accompanying the lowering of the drive of the tilling device B, the control valve 9 is brought into the vertical neutral state when the tilling depth of the tilling device B returns to the set tilling depth value. automatically returned to.

Further, when the tilling depth of the tilling device B becomes deeper than the set tilling depth value and the tilling rear cover 12 swings upward, the operating shaft 17 resists the biasing force of the spring 41 and moves the push-pull wire 33. is pressed and rotated by the inner wire 33a, the control valve 9 is switched to the raised state, and the tilling device B is driven and raised. As the drive of the tilling device B increases, the feedback rod 20 and the push-pull wire 33 operate, and control is performed when the tilling depth of the tilling device B returns to the set tilling depth value, as in the case of shallow tilling. The valve 9 is automatically returned to the vertical neutral state.

The position lever 21 includes the operation shaft 1.
The position lever 21 is frictionally moved to an arbitrary operating position by elastic deformation caused by contact with the operating piece 42 and the operating guide plate 43 for pressing and rotating the lever 7 in the upward direction against the biasing force of the spring 41. A plate spring 44 for holding is provided.

Thus, when the cam surface of the cam 35 is operated to the shallow plowing depth side, a part of the cam surface portion 35a that comes into contact with the cam follower 39, which is integral with the plowing depth setting lever 18, is removed. , the rotation support shaft 32
Formed in an arc shape with the same radius using the axis as a fulcrum,
When the control valve 9 reaches the stroke end, the operating force accompanying the swinging displacement of the cover 12 is applied to the operating shaft via the cam follower 39, while allowing the tilling rear cover 12 to swing upward further. The cam mechanism 45 constitutes a cam mechanism 45 that can prevent transmission to the cam mechanism 17.

In addition, when the tilling depth setting lever 18 is operated to the deep tilling depth position, the upward swinging distance of the tilling rear cover 12 is small and the operating distance of the operating shaft 17 itself is large, so that the control valve 9 There is no need to apply excessive operating force to the device, and the above-mentioned measures are not necessary.

In the figure, reference numeral 46 denotes a screw-type expansion/contraction adjustment tool interposed in the inner wire 33a of the push-pull wire 33.

[Brief explanation of drawings]

Fig. 1 is a side view of the rear of the riding type cultivator according to the present invention, Fig. 2 is a plowing depth control system diagram, Fig. 3 is a diagram of the relationship between the control valve, lift arm, and position lever, Fig. 4, FIG. 5 is an enlarged view of each main part. A... Traveling machine body, B... Tilling device, 1... Hydraulic actuator, 9... Control valve, 1
2... Rear tilling cover, 18... Tilling depth setting lever, 19... Mechanical linkage mechanism, 45... Cam mechanism.

Claims (1)

[Scope of utility model registration request] A rotary tilling device B equipped with a tilling rear cover 12 that can freely swing up and down as the tilling depth changes is connected to the traveling body A through a hydraulic actuator 1 so as to be able to be driven up and down, and the tilling rear cover 12 so that the plowing depth of the rotary tillage device B is maintained within the set range in conjunction with the vertical rocking displacement of the rotary tiller B.
In the plowing depth control device for a tiller, which is provided with a mechanical linkage mechanism 19 for controlling the operation of the control valve 9 of the hydraulic actuator 1, the control valve 9 is provided in the mechanical linkage mechanism 19.
When reaching the stroke end, while allowing further upward swinging of the tilling rear cover 12, it restricts the operating force associated with the swinging displacement of this cover 12 from being transmitted to the control valve 9 side. A tilling depth control device for a tiller, in which a cam mechanism 45 is provided in contact with a tilling depth setting lever 18.