JPH0340697Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The limit switch for the hit angle sensor is closed and the solenoid valve is activated depending on the hit angle of the work equipment that follows the direction change of the tractor, and the rod of the hydraulic cylinder is expanded and contracted to control the wheel. In a steering device that can automatically change direction, by adjusting the position of the limit switch for the hit angle sensor, the point at which a signal is issued for returning straight or turning left or right can be delayed or accelerated. It is possible to make adjustments to match the individual configuration of the work area, the gap between the rear wheels of the tractor and the wheels of the work equipment, the width of the wheels of the work equipment, etc., or to issue signals suitable for the worker to perform steering. The present invention relates to a wheel steering device for a tractor towing work machine.

Technical Background In a field where a tractor and a working vehicle towed by the tractor are used, there is a place at both ends of the ridge where the tractor and working vehicle can change direction, that is, "macra land".
We need a vacant lot.

This makura land makes it impossible to produce crops at all.

Although the area of the pillow pad, especially the large size, is more convenient for the operation of the tractor, it should be made as small as possible from the viewpoint of production.

Therefore, efforts are being made to develop a working machine configured to enable the working machine to turn in a small radius on the above-mentioned pillow ground.

In general vehicles, if the wheel base is large, the difference between the inner wheels of the rear wheels is also large, and therefore the turning radius of the rear wheels is much larger than the turning radius of the steering wheel.

In the case of field work equipment, it is pulled by a tractor, so if the work equipment is not equipped with a steering mechanism, there will be a wheelbase relationship between the rear wheels of the tractor and the wheels on the work equipment side. Therefore,
There is a difference between the inner wheels based on the track on the rear wheels of the tractor. Therefore, in such a case, the tractor operator must maneuver with consideration to the ruts of the rear wheels, since the rear wheels of the tractor will basically be running in a curve relative to the wheels of the work vehicle.

In such a situation, a large pillow pad is required.

For this reason, in order to increase production by reducing the width of the pillow pad as much as possible, the wheels of the working vehicle are given maneuverability in conjunction with the steering of the tractor that pulls the working vehicle. This is what I did.

Technology to reduce the turning radius by giving maneuverability to the wheels of articulated vehicles in this way also exists for trailers, etc., but the purpose of these techniques is to simply reduce the turning radius. The goal is to achieve the following.

The technology aimed at by the present applicant is such that there is a traveling trajectory of a work vehicle in an agricultural machine, for example, a tractor comes out from a ridge onto a pillow ground, rotates at the end of the ridge in a direction perpendicular to the ridge direction, and, Even when the working vehicle is still in the ridge position, the wheels of the working vehicle can move straight along the ridge until it reaches the pillow ground,
Another purpose is to enable the wheels of the working vehicle to run parallel to the ridge from the edge of the ridge when entering the ridge section again from the pillow ground.

That is, the purpose of these is to completely eliminate the need for the wheels of the tractor and the towed working vehicle to tread on the ridge for turning operations even at the edge of the ridge.

The basic technical idea is that the wheels of a working vehicle have the same form as the relationship between the trailing wheels and the railway track, which allows the wheels to run along the same trajectory as the ruts of the rear wheels of the tractor.

The steering mode of the wheels of the work vehicle that achieves the above purpose is such that when the tractor starts turning, the wheels start at a gentle steering angle with respect to the vehicle.
The angle gradually increases, a sharp turn is made at a certain point, and the second half is completely opposite to the first half. Therefore, the overall shape of the working vehicle is It is designed to turn in a small radius.

This is used to mechanically read the displacement of the connection angle provided on the hitch that connects the tractor and work vehicle, and uses this as the driving force for hydraulic operation.

These steering instruction mechanisms are installed on the working machine side and receive a hydraulic power source from the tractor side.

In a work vehicle, the steering instruction mechanism is basically set to operate according to certain set standards, but it is used in conjunction with a tractor that is individually owned by the recipient. The tractors provided by these recipients vary greatly in terms of horsepower, size, connection position, etc., and when using the work vehicle, fine adjustments are required to match the function and purpose of the work vehicle. The cases that must be carried out are prerequisites.

In addition, there are cases where the same beneficiary changes the wheel spacing of the work vehicle depending on the type of work, even if the tractor is the same, depending on the season.

That is, the ridge size varies depending on the type of agricultural product, and the number of ridges spanning the ridge varies.

Furthermore, the vehicle length center line of the work vehicle and the vehicle length center line of the tractor do not always coincide. That is, in order to always match the ruts on one side of the tractor with the ruts on one side of the work vehicle, the ruts on the other side of the work vehicle, which have different vehicle width dimensions, do not match the ruts on the other side of the tractor, and therefore,
The aforementioned centerline mismatch naturally occurs. Therefore, the work vehicle is always positioned diagonally rearward, and diagonal traction is the proper connection form. As mentioned above, the angle at which the slope is formed during diagonal traction varies depending on the type of tractor, and in order to obtain the correct configuration, the instruction mechanism must be finely adjusted each time the connection is performed. It is.

Prior Art Rather than a conventional technology, the one in Japanese Patent Application Laid-Open No. 60-230395, which the present applicant previously filed, had a limit switch that was fixed at a fixed position, making it impossible to make fine adjustments. be.

Problems that the invention aims to solve Tractors that tow working equipment vary in shape, especially vehicle size, depending on the owner.
On the other hand, the angle detection means installed on the work equipment side that issues the steering designation has a certain numerical value memorized that performs a preset function, so that the distance between the rear wheels of the tractor and the wheels of the work equipment can be changed depending on the size of the tractor. Therefore, the steering start, angle, steering end, etc. of the wheels on the side of the work machine will be different from the set values.
The desired precision of action may not be obtained.

Furthermore, in addition to these, an attempt was made to solve the problem that the limit switch does not operate reliably when it is necessary to turn the handle early or late due to the location of the work machine or the habits of the worker. The idea is to do so.

Means to Solve the Problem This invention was developed to achieve the above-mentioned purpose by closing either the left or right limit switch of the hit angle sensor by rotating the handle, which switches the solenoid valve and operates the cylinder. Then, when the slide rod is moved to either the left or right direction, the solenoid valve circuit is held and the slide rod continues to move to change the direction of the wheels.Then, by returning the handle, the solenoid valve circuit is switched and the switched circuit is activated. In a tractor towing work machine, which is characterized by returning the wheels to a straight running state by holding and operating the cylinder and returning the slide rod to the center position, the case is fixed horizontally near the front end of a hitch attached to the front of the work machine. , the lower horizontal member of the drawbar is pivotally attached to the front end of the hitch, and a bolt is fixed to the upper horizontal member of the drawbar facing downward. In addition to fixing the drawbar interlocking cam protruding from the cam, a left/right turn limit switch and a straight return limit switch for the hit angle sensor are installed inside the case, and each limit switch is individually positioned on a circular line centered on the drawbar interlocking cam. In addition, the drawbar interlocking cam is attached to an arbitrarily set position, and the drawbar interlocking cam is mounted on a radial line centered on the drawbar interlocking cam so that the movement toward and away from the center of the drawbar interlocking cam can be adjusted. The drawbar interlocking cam is cut out to form a flat part or a cam groove is cut out, and a limit switch roller for straight travel is brought into contact with the center of the flat part or at the position of the cam groove, and a limit switch for left and right turns is set. The rollers are brought into contact with both ends of the flat part or the circular parts on both sides of the cam groove.

Embodiment A circuit A is formed by connecting the positive side of a power supply 1, a relay 2, a resistor 3, a diode 4, an automatic contact 6 of a pushbutton switch 5, and a limit switch 8 of a steering sensor 7 in series.

Negative side of power supply 1 and steering sensor 7
A circuit B is formed by connecting the negative side of the limit switch 8, the negative side of the hit solenoid valve 9, and the negative side of the steering solenoid valve 10. A limit switch 13 for left and right operation of the hit angle sensor 12 and a contact 14 for left and right operation of the solenoid valve 10 are connected in parallel to a circuit C connected in series with the power supply 1 and the relay 11.

In circuit C, the two contacts 16 of the snap switch 15 are connected in parallel with the relays 2 and 11.

Power supply 1, one contact 17 of the snap switch 15, and the limit switch 13 of the hit angle sensor 12
are connected in series to form circuit D.

A manual contact 19 of the push button switch 5 is provided between the power source 1 and the circuit C. A circuit E is formed by connecting the limit switch 18, the limit switch 8 of the steering sensor 7, and the circuit C in series. A circuit F is formed by connecting the power source 1, left and right push button switches 22 for hits, and left and right solenoid valves 9 in series.

Diode 23 connects circuit B, circuit C, and circuit F.
The wires are connected via the .

24 is a reception plug, and 25 is a shell set.

A hydraulic cylinder 34 is provided across the axle 32 of the working machine 31 towed by the tractor 30 and the direction changing shaft 33 provided parallel to the axle 32. That is, the cylinder is attached to the axle 32 and the direction of the piston rod is changed. In addition to being attached to the shaft 33, oil chambers 35 at the front and rear of the hydraulic cylinder 34,
36 is the oil pipe 3 of the solenoid valve 10
7 and 38 are connected and opened, and an oil pipe 39 of a hydraulic package is connected and opened to the solenoid valve 10. Also, hydraulic cylinder 34
A slide rod 41 covered with a dust-proof case 40 is installed in parallel with the dust-proof case 40, the dust-proof case 40 is attached to the axle 32, and the slide rod 41 is attached to the direction changing shaft 33. The slide rod 41 has three lock grooves 42 for going straight, turning right, and turning left. , 43 and 44 are carved at regular intervals, one or two limit switches 8 are attached to the approximate center of the case 40, and a roller 45 is attached to the opening/closing contact of the limit switch 8, and the roller 45 is inserted into the locking grooves 42, 43. ,44
The limit switch 8 is formed so that it opens and closes when it is fitted.

To explain in detail the structure of the hitch angle sensor 12, the hitch 46, the drawbar 47, the drawbar interlocking cam 48, and the limit switches 13, 18, 13, the support plate 53 is vertically fixed near the front end of the hitch 46, The case 54 is horizontally fixed to the front. A lower horizontal plate 55 of a draw bar 47 is pivotally attached to the front end of the hitch 46 with a bolt 56 and a nut 57, a shaped support plate 59 is provided on the upper horizontal member 58 of the draw bar 47, and a horizontal plate 59a of the support plate 59 is attached downwardly. Fix the direction bolt 60.

It is desirable that the axes 61 of the bolt 60 and the bolt 56 be concentric. The bolt 60 is inserted and fixed into the inner ring hole 64 of a radial bearing 63 that is attached to the upper plate 62 of the case 54 so as to be coaxial with the bolt 60, and the tip of the bolt 60 protrudes into the case 54, and the drawbar interlocking cam 48 is attached to the screw portion. Insertion nut 65
and fix it integrally with the bolt 60.

In the case of the embodiment shown in FIG. 7, there are limit switches 1 for three hit angle sensors 12 in the case 54.
3, 18, and 13 can be attached,
The left and right limit switches 13 are fixed to the vertical part of a ⊥-shaped (inverted T-shaped) support plate 66, the center limit switch 18 is fixed to the vertical part of a support plate 67, and the support plates 66 and 67 are bored into the case 54. It is attached to the elongated holes 68 and 69 with bolts 70 and wing nuts 71 so that its movement can be adjusted freely.

The rollers 49 of the limit switches 13, 18, and 13 are brought into contact with the drawbar interlocking cam 48. A portion of the drawbar interlocking cam 48 is cut out to form a flat part 72, and the limit switch is placed in the center of the flat part 72. 18 rollers 49 are in contact with each other, and the rollers 4 of the left and right limit switches 13 are in contact with each other.
9 is brought into contact with the circular portions 73 at both ends of the flat portion 72.

Furthermore, regarding the elongated holes 68 and 69, the left and right elongated holes 68 are formed in a concentric arc shape from the center of the bolt 60, and the elongated hole 69 is formed in the center to be long in the front-rear direction. Further, both ends of the left and right support plates 66 are rotatably attached to bolts 60.

When the support plate 67 is brought closer to the drawbar interlocking cam 48, the operating point (signal for straight return) becomes slower (that is, the angle approaches 0), and when it is moved away from the drawbar interlocking cam 48, the operating point becomes faster (that is, when the angle is large, the signal for straight return is ).

Furthermore, by making the support plate 66 adjustable in the direction of rotation with respect to the center of the drawbar interlocking cam 48, the point at which a signal to the right or left is issued can be delayed or accelerated.

In the case of the embodiment shown in FIG. 8, there are four limit switches 1 for the hit angle sensors 12 in the case 54.
3, 18a, 18b, 13 are attached, but limit switches 13, 18a, 18
b, 13 are all fixed to the vertical part of a ⊥-shaped (inverted T-shaped) support plate 74, and the support plate 74 is attached to an elongated hole 75 bored in the case 54 with a bolt 70 and a wing nut 71 so that its movement can be adjusted freely. Limit switch 1
The rollers 49 of 3, 18a, 18b, and 13 are brought into contact with the drawbar interlocking cam 48, and two cam grooves 76 are cut out oppositely at the front and back of the drawbar interlocking cam 48. Position the limit switches 18a and 18b respectively,
Limit switches 13 for left and right turns are located on the left and right sides of the rear limit switch 18b, but limit switches 13, 13 are located on either side (not shown) and each limit switch 13,
The rollers 49 of 18a, 18b, and 13 are kept in contact with the drawbar interlocking cam 48.

Furthermore, the elongated hole 75 is concentrically drilled in an arc shape from the center of the bolt 60, and the front end of the support plate 74 is formed from the center of the bolt 60.
It is pivotably attached to the.

And limit switches 13, 13 for left and right turns.
By loosening the wing nut 71 and adjusting it by moving it left and right, the point at which a right or left turn signal is issued can be made later or earlier.

Limit switches 18a and 18b for returning straight forward movement
are connected in parallel, and the circuit is configured so that when either closes, a signal to return to straight travel is issued. For example, if the drawbar interlocking cam 48 rotates clockwise as shown in FIG. 8, when it returns, the front limit switch 18
A signal to return straight is issued. When the vehicle rotates counterclockwise and returns, the limit switch 18b at the rear outputs a signal to return to straight forward motion.

These timings can be changed by adjusting the limit switches 18a, 18b.

Reference numeral 22 is a push button switch for ridge matching, which is connected to a solenoid valve 9 for ridge alignment, and a hydraulic package is connected to the solenoid valve 9, and an oil pipe 39 of the solenoid valve 9 is connected to a hydraulic cylinder 51 attached to the hitch part. By pressing the push button switch 22 on either the left or right, the solenoid valve 9 is switched to send oil to the cylinder chamber, and the piston rod is expanded and contracted to move the front part of the work machine from side to side, thereby aligning the digging opening with the ridge. This is how it was done.

Function Since this invention is constructed as described above, the limit switches 13, 13 and 18 which are brought into contact with the drawbar interlocking cam 48 are connected to the drawbar interlocking cam 48.
8, that is, on a circular line of a certain radius drawn with the bolt 60 as the axis, each of the limit switches 13, 13 can be rotated to an arbitrarily set angle, and the displacement can be set. If it is fixed at this position, the action received from the drawbar interlocking cam 48 can be made faster or slower by the amount of movement.

Furthermore, in addition to the rotational movement of the limit switches 13, 13, the limit switch 18 can move forward and backward to an arbitrarily set change position on the diametrical extension of the drawbar interlocking cam 48, and can be fixed at the set position. This allows the amount of advance and retreat of the action to be finely adjusted.

Next, to describe the overall operation, first attach the drawbar 47 to the three-point link of the tractor 30 and switch the snap switch 15 to fully automatic mode, then use the tractor 30 to tow the work implement 31, and then turn it over and move on. When starting work, when the handle of the tractor 30 is turned to the left or right and the tractor 30 turns, the drawbar 47 rotates together with the tractor 30, so that the drawbar 47 rotates in either the left or right direction relative to the hitch 46. The drawbar interlocking cam 48 integrally attached to the drawbar 47 also rotates with the drawbar 47 relative to the hit 46 in either the left or right direction, and therefore the limit switch 18 provided on the hit 46 rotates in the direction of the larger radius of the flat portion 72 of the drawbar interlocking cam 48. The drawbar interlocking cam 4 either moves to the cam groove 76 and is pushed to open the circuit, or protrudes from the cam groove 76 and is pushed by the circular part to open the circuit.
8 is rotated by a certain angle (for example, 45 degrees), either the left or right limit switch 13 is positioned at the center of the flat part 72 or the cam groove 76 and closes the contact, which closes the left or right circuit of the solenoid valve 10 and operates the valve. Since it is switched, the oil chambers 35 or 3 before and after the hydraulic cylinder 34 from the oil package cage.
A dust-proof case 40 is attached to the axle 32 and the direction-changing shaft 33 so that the rod of the cylinder 34 expands and contracts and the direction-changing shaft 33 moves in either the left or right direction with respect to the axle 32.
When the inner slide rod 41 moves to either the left or the right, the limit switch 8 protrudes from the straight-advance lock groove 42 of the slide rod 41 and moves to the thicker diameter part of the slide rod 41, closing the contacts and closing the relays 2 and 11. Relay 11 is held, circuits B and C are held, and solenoid valve 10 is activated. Therefore, the solenoid valve 10
The slide rod 41 is maintained as it is and oil is pumped into the cylinder 34, so the slide rod 41 is moved either to the left or right by the action of the rod of the cylinder 34, and the direction changing shaft 33 is moved and the wheels are rotated. converts the angle. During this operation, the limit switch 8 enters the left-turn or right-turn lock groove 43 or 44 of the slide rod 41, and the limit switch 8
is turned OFF and operation stops.

When the handle is returned to the right or left, either the right or left limit switch 13 is moved from the flat part 72 of the drawbar interlocking cam 48 to the circular part 73 or cam groove 76.
When the limit switch 18 moves to the left and right circular parts of the flat part 72 and turns OFF and rotates by a certain angle (for example, 0 to 20 degrees), the limit switch 18 moves in the direction where the radius of the flat part 72 is smaller and protrudes or fits into the cam groove 76. closes the contact. At this time, either the left or right limit switch 13 closes, so either the right or left solenoid valve 10 operates, sending oil to either the rear or front oil chamber 36 or 35 of the cylinder 34.
When the slide rod 41 for contracting and expanding the rod of the cylinder 34 also moves to the right or left and the limit switch 8 closes, the relay 11 closes and holds circuits B and C until the limit switch 8 enters the lock groove 42 for straight travel. is held, the solenoid valve 10 is operated, and the slide rod 41 is moved to the right or left, so that the wheels return to the straight-ahead state.

Effects of the invention By attaching the limit switch for the hit angle sensor to the case so that it can be moved and adjusted, the point at which the signal is issued for returning straight or turning left or right can be adjusted freely, so it can be adapted to the size of the tractor, such as large or small. Furthermore, it can be adapted to the conditions of the work site or the habits of the workers.

[Brief explanation of the drawing]

Figure 1 is a plan view of the work machine, Figure 2 is a perspective view showing the relationship between the axle and the direction conversion shaft, Figure 3 is a sectional view of the slide rod, Figure 4 is a circuit diagram, and Figure 5 is the tractor and work machine. FIG. 6 is an enlarged side view of the hit angle sensor section, and FIGS. 7 and 8 are plan views of the cam and limit switch.

Claims (1)

[Scope of utility model registration request] By turning the handle, the limit switch on either the left or right side of the hitch angle sensor is closed, which switches the solenoid valve, activates the cylinder, and moves the slide rod in either direction.At the same time, the solenoid valve circuit is held and the slide rod continues to move. The vehicle is characterized by changing the direction of the wheels, then returning the handle to switch the solenoid valve circuit, maintaining the switched circuit, activating the cylinder, and returning the slide rod to the center position to return the wheels to a straight-ahead state. For tractor towing work equipment, the case is fixed horizontally near the front end of a hitch attached to the front of the work equipment, the lower horizontal member of the drawbar is pivoted to the front end of the hitch, and the lower horizontal member of the drawbar is attached downward to the upper horizontal member of the drawbar. The bolt is inserted into the top plate of the case and is rotatably attached, and the tip protrudes into the case to fix the drawbar interlocking cam. Inside the case, there is a left/right turn limit switch for the hit angle sensor and a left/right turn limit switch for the hit angle sensor. Install limit switches for returning straight travel, and set each limit switch individually to an arbitrarily set position on a circular line centered on the drawbar interlocking cam, and on a radial line centered on the drawbar interlocking cam to the center of the drawbar interlocking cam. On the other hand, it is installed so that the movement toward and away from the drawbar can be adjusted freely, and the position after arbitrary movement adjustment can be fixed. Furthermore, the drawbar interlocking cam is notched to form a flat part, or the cam groove is formed by notching it. Tractor towing work in which the rollers of a limit switch for straight travel are brought into contact with the center of the flat part or the position of the cam groove, and the rollers of the limit switch for left and right turns are brought into contact with both ends of the flat part or the circular parts on both sides of the cam groove. Machine wheel steering device.