JPH0530804A - Operating unit for working machine lifting and lowering control in tractor - Google Patents

Abstract

PURPOSE:To make it possible to use in a manner additionally attached on inner wall face of rear wheel fender in a tractor without being an obstacle to an operator as a small-sized and flat operating unit completely finished. CONSTITUTION:A base plate (17) is fixed and supported in the interior of a small-sized and flat cover case (11) and a volume type position setter (22) for setting hanging height of an operating machine and its operation lever (32) each pivoted to the base plate (17) are pivoted and connected so as to be to integrally turn by a parallel link mechanism and the above-mentioned cover case (11) is attached to the inner wall face of a rear wheel fender (16) and the above-mentioned operating lever (32) is provided so as to turn and operate from the outside of the cover case (11).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating unit for controlling the lifting and lowering of a working machine in a tractor, and more particularly, by independently forming an operating unit which is independent of the rear wheel fan of the tractor and has a small overall flat unit. , The rear wheel fan is not required to be specially shaped, and the rear wall fan can be freely attached to the inner wall of the fan without any hindrance to the operator.

[0002]

2. Description of the Related Art When automatically controlling the lifting and lowering of a working machine of a tractor, for example, as is apparent from FIG. 10, a volume type positive position is provided on the rotation axis of a lifting arm (1) for lifting the working machine. A sensor (2) is installed as an accessory, and the detected voltage value of the working machine hanging height detected by this is input to the control unit (3) by the micro computer, while the operator operates the lever (4) from above the driver's seat. Alternatively, the dial is rotated to set the target voltage value of the working machine hanging height by the volume type position setting device (5), and this is also input to the control unit (3), and the set voltage is set. By the output signal based on the comparison difference between the value and the detected voltage value, the working machine is automatically lifted up and down to the target set height via the working machine lifting control solenoid valve (6) and the hydraulically actuated cylinder (7). That mechanism is known.

In this case, the position setting device (5) is embodied by a rotary potentiometer, and the lever (4) or dial for rotating the position setting device (5) is
It is customary to preliminarily assemble and integrate a rear wheel fan in a tractor so as to form a part of the structure.

That is, the riding space defined by the rear wheel fan of the tractor is narrow, and when the lever (4) or dial is extended on the inner wall surface of the fan, the operator can set the position setting device (5).
Since it becomes difficult to perform the turning operation of the, the conventional method is that the upper wall surface and the inner wall surface of the fander are partially depressed to expose the rotation axis of the position setting device (5) inside thereof.
A dial is attached to the rotary shaft integrally, or a lever guide groove is cut out on the upper wall of the fan, and the position setting device (5) is integrally rotated to the lower end of the lever that is pulled out from here to the standing state. It is assembled to move.

[0005]

However, in any of the above-mentioned conventional means, since it is necessary to process the fender itself into a special shape, it cannot be universally attached and used on a tractor of various specifications. In addition, the mounting positions of the lever (4) and the dial cannot be changed or adjusted to facilitate the turning operation according to the wishes of the operator.

Particularly, in the case of a rotary operation type using a dial,
Since the lifting and lowering of the work machine is a vertical movement, the operator feels uncomfortable when setting the position setting device (5).
It's difficult to use. On the other hand, even with the rotation operation type with the lever (4),
Since the lever guide groove is largely opened on the upper wall surface of the fan, it is likely to be directly exposed to rainwater and mud during farming, which may cause malfunction of the position setting device (5) and other troubles.

Moreover, the output voltage of the position setting device (5) at the highest position and the lowest position of the working machine is required only after the lever (4) is assembled with the fan through the lever guide groove. Since the value cannot be adjusted, the adjustment work cannot be performed easily, and it is also difficult to set the adjustment state with high accuracy.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to improve such a problem, and for that purpose, has a U-shaped cross-section having a rear surface which is a mounting surface for a rear wheel fender of a tractor and which has an opening. A small flat cover case with lever guide guide grooves arranged in a row on the arc body surface, a base plate fixedly supported inside the cover case in an upright state, and a lifting height of a working machine towed by a tractor In order to set, the volume type position setting device assembled to the base plate, the rotating arm integrally extended upward from the rotating shaft of the position setting device, and the rotating shaft of the position setting device. The lower end portion is pivotally attached to the base plate via parallel fulcrum shafts, and extends from the lever guide slot of the cover case while extending in parallel with the rotating arm. And create the lever, in order to use integrated twice operating a rotating shaft and the operating lever of the Pojishiyon setter,
A link piece that pivotally connects the midway portion of the operation lever and the upper end portion of the rotating arm, and a compression spring material fitted to the fulcrum shaft so as to constantly apply a braking force to the operation lever,
A stopper plate attached and fixed to the base plate as an accessory is provided, and when the operating lever is raised, the link with the operating lever is set so that the lifting height of the working machine is set to the highest position. While the pivot pin that connects the one with the one is locked to the punching edge of the base plate, when the operating lever is laid down to set the working machine to the lowest position, the pivot pin is The main feature is that it is set so as to be locked to the punching edge of the stopper plate, and that the back surface of the cover case is attached to the inner wall surface of the rear wheel fander in its covered state and used. It is a thing.

[0009]

According to the above construction of the present invention, the operating unit is finished as a unit independent from the rear wheel ender of the tractor, and the volume type position setting device and the volume type position setting device are provided inside the small flat cover case. The operation lever is pivotally connected via a parallel link mechanism so that it can rotate integrally, and the lever lead-out guide groove including the rotation angle range of the operation lever also has an arc barrel surface of the cover case. Since it has a pre-formed opening, it can be freely and compactly attached to the desired location on the inner wall surface of the above-mentioned fan, and it is not only versatile for tractors of various specifications, but also an obstacle to the operator. There is no fear of giving.

Further, the pivot pin connecting the operating lever and the link piece is engaged with the punching edge of the base plate so that the maximum lifting limit of the working machine can be positioned. The pin is engaged with the punching edge of the stopper plate so that the lowermost limit of the working machine can be positioned. Therefore, the bending stress generated by the turning operation of the operating lever causes It does not propagate or propagate up to the axis of rotation and can reliably prevent problems with the position setting device, which helps improve durability.

Further, due to the locking action of the pivot pin,
Since the maximum rise limit and the minimum fall limit of the working machine are positioned, even when adjusting the output voltage value at the position setting device at each limit position,
Before incorporating the base plate with the above mechanism assembled into the cover case, the adjustment work can be performed efficiently,
Moreover, a highly accurate adjustment state can be easily obtained, and since it can be built in the cover case after the adjustment is completed,
Excellent overall workability.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The specific construction of the present invention will be described in detail below with reference to the illustrated embodiments. In FIGS. 1 to 8 showing an operating unit for controlling the working machine up and down, (11) is seen from the front. It is a fan-shaped cover case with a vertical dimension-about 110 mm, a horizontal dimension-about 150 mm, and a depth dimension-about 45 mm with a rounded shape, which is plastically processed from a single metal plate to a U-shaped cross section with a rear surface opening. Has been done. The entire mechanism described later can be easily assembled into the cover case (11) from the rear surface of the opening.

Reference numeral (12) is a lever lead-out guide groove arranged in an opening on a large arcuate barrel surface from the upper surface to the front surface of the cover case (11), and the opening angle range (α) is about 1.
It is set to 00 degrees. Similarly, (13) is a mounting seat bent outward from the opening edge of the cover case (11) at a right angle, and there are a plurality of bolt receiving holes (14 in the figure). The cover case (11) is distributed over the opening at a predetermined interval, and the cover case (11) is inserted into the bolt receiving holes (14) through the bolt receiving holes (14). As shown in FIG. 9, it will be fixed to the inner wall surface of the sheet afterwards.

That is, since the cover case (11) is made small and flat with the above-mentioned dimensions, it is not necessary to specially shape the rear wheel fan (16) of the tractor, and the inner wall surface of the fan (16) is not required. The cover case (11) can be attached and used compactly by simply opening a communication hole (not shown) corresponding to the bolt receiving hole (14) to a desired position of the above. Not only is it versatile for tractors of various specifications, but it also has no risk of impeding the operator when riding in the driver's seat or operating the levers described below. In addition, it goes without saying that, in the mounted and used state, the back surface of the cover case (11) is covered by the fan (16).

Reference numeral (17) denotes a base plate built in substantially the center of the cover case (11), which is a front view of a single metal plate having a front sloping surface (y) as shown in FIG. It is punched out in a polygon. (18) and (19) are a plurality (two in total in the figure) of angle stays that stably and fixedly support the base plate (17) in an upright state, one side surface of which is the inner peripheral surface of the cover case (11). The base plate (17) is joined to the remaining other side surface, and is fastened to the bolt (20) via the nut (21).

In this case, as suggested from FIGS. 2 to 4, one stay (18) is the upper rear portion of the base plate (17) to the rear surface of the cover case (11) and the other stay (19) is also the base plate. A large arcuate barrel surface of the cover case (11) in which the middle part of the lower end of (17) is fixedly supported on the lower surface of the cover case (11), and the lever lead-out guide groove (12) is arranged in a row, and a base plate. The stays (18) and (19) do not exist at all in the empty space of (17) facing the front downward slope (y).

Reference numeral (22) is a volume type position setting device (rotating type potentiometer) for setting a target lifting height of the working machine, and the base plate (17) is attached via the mounting bracket (23). It is installed on the back of. Reference numeral (24) is a fixing bolt of the mounting bracket (23) to the base plate (17), and a stupid hole for receiving this is formed as an elongated hole (25) in the mounting bracket (23) to form an opening. Due to the assembly of the position setting device (22) and the operation lever described later, the output voltage value of the setting device (22) can be easily and finely adjusted.

Further, (26) is a position setting device (22).
The rotation shaft of the base plate (17) is horizontally exposed from the back surface to the front surface of the base plate (17), and the lower end portion of the forked fork-shaped rotation arm (27) is fitted to the tip end portion thereof. , Bolts (28) and nuts (29) are integrally fastened. The arm (27) rotates together with the position setting device (22). Reference numeral (30) is a lock wash of the nut (29), and reference numeral (31) is a signal code derived from the position setting device (22) through the cover case (11).

On the other hand, (32) is an operating lever of the position setting device (22), which is also located in front of the base plate (17) and extends in parallel with the rotating arm (27). The upper end portion is led out to the outside of the cover case (11) through the guide groove (12). Reference numeral (33) is a grip integrally attached to the upper end of the grip, and (34) is a fulcrum shaft for rotatably pivoting the lower end of the operating lever (32) to the base plate (17). The bolt is slightly thicker than the rotating shaft (26) and penetrates the base plate (17) in parallel with the rotating shaft (26).

(35) is a nut fastened to the fulcrum shaft (34) from behind the base plate (17), and (36)
Is also a bearing boss of the fulcrum shaft (34), which is pre-welded and integrated with the base plate (17), and a disc spring (between the boss (36) and the nut (35) which face each other. 37) and the thrust washer (38) are also inserted in parallel. By the disc spring (37),
The elastic braking force is constantly applied to the operation lever (32). However, as long as the braking force can be applied,
Of course, various compression spring materials may be used instead of the disc spring (37).

Further, (39) is the position setting device (2
2) A link piece for interlocking the rotating arm (16) and the operating lever (32), and its forked fork-shaped front end portion is sandwiched at a mid-height position of the operating lever (32), While being pivotally coupled by a pivot pin (40), the remaining rear end is inserted into the upper end of the bifurcated fork-shaped pivot arm (27), and another pivot pin (41) ), It is mounted so that it can rotate freely,
A parallel link mechanism is formed on the bush.

In this case, as is clear from FIGS. 4, 6 and 7, the pivot pin (40) connecting the link piece (39) and the operating lever (32) also rotates with the link piece (39). It is longer than the pivot pin (41) connecting with the arm (27) and is extended toward the back of the base plate (17), and the operating lever (32) is raised as shown by the solid line in FIG. When the working machine is set to the highest position (H), the long pivot pin (40) is intentionally moved to the front-lowering inclined surface (y) of the punching edge in the base plate (17). It is designed to be stably locked to.

That is, the front descending inclined surface (y) forming the punching edge of the base plate (17) can function as a limit stopper for determining the highest position (H) of the working machine by the operating lever (32). The pivot pin (4
The mounting position of 0) is determined accurately in advance. Therefore, the pivot pin (4) of the operating lever (32)
0) to the front downward slope (y) of the base plate (17)
The work implement is raised to the highest position (H) while locked to
Position setting device (2
The output voltage value of 2) can be adjusted easily and highly accurately.

Further, (42) is a base plate (17).
Is a stopper plate additionally joined to the front part of the lower end of the base plate from the rear and fastened via bolts (43) and nuts (44), and faces the front downward slope (y) of the base plate (17). It is also punched from a single metal plate as a triangle in front view with a rearwardly sloping surface (x). In that case, the stopper plate (42) also serves as an angle stay (19), a bolt (20) and a nut (21) for fixing the middle part of the lower end of the base plate (17) to the lower surface of the cover case (11), It is apparent from FIGS. 2 and 4 that it is fixed under the two-point support state.

When the operating lever (32) is laid down as shown by the solid line in FIG. 5 and the working machine is set to the lowest position (L), the operating lever (32) is linked to the operating lever (32). The pivot pin (40) with the piece (39)
However, as is clear from FIG. 7, the stopper plate (4
Sloping surface (x) after the punching edge in 2)
The operation lever (32) is used to deliberately lock the position of the lowering limit of the working machine.

Therefore, under the condition that the pivot pin (40) of the operating lever (32) is locked to the rearwardly descending inclined surface (x) of the stopper plate (42), the working machine is at the lowest position ( L), the output voltage value of the position setting device (22) can be easily and accurately adjusted.

At this time, since a stupid hole for receiving the bolt (43) is formed as an elongated hole (45) in the stopper plate (42), a separate bolt () for the angle stay (19) is formed. When the stopper plate (42) is rotated up and down along the elongated hole (45) around the fulcrum 20) as a fulcrum, the mounting height of the stopper plate (42) with respect to the base plate (17) changes. As a result, the output voltage value of the position setting device (22) can be easily fine-tuned. However, the long hole (45) useful for the fine adjustment is provided with the stop plate (42).
Alternatively, an opening may be formed in the base plate (17) instead of the above.

(Β) shows the range of the rotation angle of the operating lever (32) from the highest position (H) to the lowest position (L) of the working machine, which is about 78 degrees. Lever guide groove (1) in the cover case (11)
The size is slightly smaller than the opening angle range (α) of 2). (46) is its lever guide groove (12)
It is a strip-shaped index label that is attached from the top surface to the front surface of the cover case (11) so as to be parallel to the above. The operator can easily perform the above-mentioned lever operation by visually checking it. .

Reference numeral (47) is a general term for stopper knobs fitted from the outside into the lever lead-out guide groove (12), and the operating lever (32), as suggested by FIG. It is used to regulate the positioning at any midpoint of the range (β). Therefore, when not in use, as shown in FIG. 2, it is fixedly maintained at the lower end front part of the lever guide groove (12) so as to be retracted from the lowest position (L) of the working machine.

The opening angle range (α) of the lever lead-out guide groove (12) is dimensioned larger than the rotation angle range (β) of the operating lever (32), so that the lever lead-out guide remains by the difference in size. The stopper knob (47) can be retracted to the lower front part of the groove (12).

The stopper knob (47) is embodied by a bolt (48) having a large head that serves as a knob. When the stopper knob (47) is screwed from the outside, it is fitted onto the shaft portion. The pair of friction packings (49) stop at that position by clamping and fixing the cover case (11). On the contrary, the screw can be slid back and forth to freely slide along the lever guide groove (12). (50) is a pair of washers sandwiching both packings (49), (51) is a nut,
(52) is a retaining pin.

The operating unit of the present invention constructed as described above is independent from the rear wheel ender (16) of the tractor in advance, and is a unit body capable of performing its original function as a whole. It's finished.

That is, a volume type position setting device (22) for presetting the lifting height of the working machine and its operating lever (32) integrally rotate through a parallel link mechanism. The lever lead-out guide groove (12), which is pivotally connected so as to obtain and includes the rotation angle range (β) of the operation lever (32), also has a pre-opening formed on the arc body surface of the cover case (11). Since it has been, the above Fender (16)
It can be freely and universally retrofitted to desired places on the inner wall surface.

Moreover, in particular, the pivot pin (40) connecting the operating lever (32) and the link piece (39) is received by the front downward slope (y) forming the punching edge of the base plate (17). While the highest position (H) of the working machine is determined, the pivot pin (40) is also received by the rearward descending inclined surface (x) forming the punching edge of the stopper plate (42). As a result, the lowermost position (L) of the working machine is limited. Therefore, when adjusting the output voltage value in the position setting device (22) at each position (H) (L), Before the base plate (17) having the above-mentioned mechanism is fixedly supported inside the cover case (11), the work can be performed extremely efficiently and comfortably, and the adjustment state is highly accurate. Getting can, so that the sufficient if the fixed assembly to the cover case (11) after the adjustment.

The so-called self-contained unit body cover case (11) is attached to the inner wall surface of the rear wheel fan (16) of the tractor by a plurality of bolts (15).
It is attached and fixed by.

When the operating unit according to the present invention is used, the operating lever (32) is now set to its upright position as shown by the solid line in FIG.
Assuming that the set voltage value and the detected voltage value of 2) match and the working machine is suspended at the highest position (H), when lowering the working machine from the stopped state, The operation lever (32) is rotated forward by a desired amount in the lying position.

In this case, the desired amount is indicated by the index label (4
6) and position and fix the stopper knob (47) at the desired target location, as suggested by FIG. However, when the working machine is lowered to the lowest position (L), it goes without saying that the stopper knob (47) is retracted to the lower end of the front portion of the lever guide groove (12) as shown in FIG.

By rotating the operating lever (32) to a position where it is stopped by the stopper knob (47),
The position setting device (2
The rotation shaft (26) of 2) also rotates, the set voltage value becomes smaller than the detection voltage value detected by the position sensor, and the output signal based on the comparison result of both voltage values becomes negative. Therefore, the working machine descends to the target desired height position set by the lever operation, and automatically stops when the detected voltage value matches the set voltage value.

On the contrary, the operating lever (32) is set to its laid-down posture as shown by the solid line in FIG.
Assuming that the working machine is stopped at the lowermost position (L), when raising the working machine from that state, the operation lever (32) is desired to move backward toward the standing posture. The rotation operation is performed by the amount to be performed.

Then, the rotating shaft (26) of the position setting device (22) also rotates integrally with this, and the set voltage value becomes larger than the detected voltage value, and the two voltage values are compared. Since the output voltage value based on the difference is positive, the work implement rises to the target desired height position set by the lever operation, and the difference between the set voltage value and the detected voltage value becomes zero. Eventually, it will be kept in a stopped state.

When the lifting height of the working machine is set to either the highest position (H) or the lowest position (L), the operating lever (32) and the rotating arm (as described above) are set. A pivot pin (40) for connecting with 27) is quickly locked to the front downward slope (y) of the base plate (17) or the rear downward slope (x) of the stopper plate (42), Since it is properly held in each positioning state, the bending stress generated by the turning operation of the operation lever (32) does not propagate or propagate to the turning shaft (26) of the position setting device (22). , And the interposition of the parallel link mechanism, the stress is effectively blocked by itself, and as a result, the trouble of the position setting device (22) can be reliably prevented and its durability is improved. It will be extremely exciting.

[0042]

As described above, according to the present invention, the operation unit for controlling the working machine up and down in the tractor has a U-shaped cross-section having a rear surface which is an attachment surface for the rear wheel fan (16) of the tractor because of its constitution. None, and a small and flat cover case (11) in which the lever lead-out guide groove (12) is provided in a row on the arcuate body surface, and the cover case (1
1) A base plate (17) fixedly supported in the upright state, and a volume-type position assembled to the base plate (17) in order to set the lifting height of a working machine towed by a tractor. Setting device (22)
A rotary arm (27) that is integrally extended upward from the rotary shaft (26) of the position setting device (22) and is parallel to the rotary shaft (26) of the position setting device (22). The lower end is attached to the base plate (1 through the fulcrum shaft (34).
7) and an operating lever (32) led out from a lever lead-out guide groove (12) of the cover case (11) while extending in parallel with the rotating arm (27) and the position setting. In order to integrally rotate the rotating shaft (26) of the device (22) and the operating lever (32), the middle part of the operating lever (32) and the upper end of the rotating arm (27) are pivotally supported. In order to constantly apply a braking force to the link piece (39) to be connected and the operation lever (32), the fulcrum shaft (3
4) is provided with a compression spring material (37) fitted to the base plate (17) and a stopper plate (42) additionally joined and fixed to the base plate (17), and the lifting height of the working machine is raised to the highest position ( H), when the operation lever (32) is raised, the operation lever (32) is raised.
The pivot pin (40) connecting the link piece (39) with the link piece (39),
While locking the punching edge of the base plate (17), the operating lever (32) is laid down to set the working machine to the lowest position (L).
The pivot pin (40) is set so as to engage with the punching edge of the stopper plate (42), and the rear surface of the cover case (11) is attached to the rear wheel fan (1).
Since it is designed to be attached to the inner wall surface of 6) in a closed state, it has the effect of completely solving the problems of the prior art described at the beginning.

That is, the present invention is finished as a small flat unit which is independent of the rear wheel fan (16) of the tractor as an operating unit itself, and inside the small flat cover case (11), The volume type position setting device (22) and its operating lever (32) are pivotally connected to each other via a parallel link mechanism so that they can rotate integrally, and the operating lever (32) is also provided.
Lever guide groove (1) including the rotation angle range (β)
Also in 2), since the pre-opening is formed on the arc body surface of the cover case (11), it can be freely and compactly attached and used at a desired position on the inner wall surface of the fan (16). Not only is it versatile for tractors of various specifications, but it also does not hinder the operator.

The operating lever (32) and the link piece (3
While the pivot pin (40) for connecting with 9) is engaged with the punching edge of the base plate (17), the upper limit of the working machine is positioned, while the pivot pin (40) is also positioned. 40) is a stopper plate (4
By engaging with the punching edge of 2), the lowermost limit of the working machine is positioned, so that the bending stress generated by the turning operation of the operation lever (32) causes the position setting device ( The position setting device (22) does not propagate or propagate to the rotation shaft (26) of the device 22).
The trouble of can be surely prevented, which helps improve the durability.

Furthermore, since the upper limit and the lower limit of the working machine are positioned by the locking action of the pivot pin (40), the position setting device (22) at each limit position is set. ), The base plate (17) having the above-mentioned mechanism assembled therein is incorporated into the cover case (11).
The adjustment work can be efficiently performed, and a highly accurate adjustment state can be easily obtained. Since the adjustment work can be incorporated in the cover case (11), the overall assembling workability is also excellent.

In particular, if the configuration of claim 2 is adopted,
Stopper plate (42) to base plate (17)
On the other hand, by moving along the long hole (45),
Position setting device (22) at the lowermost limit position of the working machine
It can be said that it is more and more beneficial because the output voltage value at can be easily fine-tuned.

[Brief description of drawings]

FIG. 1 is an external plan view of an operating unit according to the present invention.

FIG. 2 is a sectional front view taken along line 2-2 of FIG.

FIG. 3 is a side sectional view of FIG.

FIG. 4 is a sectional plan view of FIG.

FIG. 5 is a sectional front view showing a state in which the operating lever is turned down corresponding to FIG.

6 is a partial enlarged cross-sectional view taken along line 6-6 of FIG.

7 is a partially enlarged cross-sectional view taken along the line 7-7 of FIG.

8 is a sectional front view showing a slide operation state of the stopper knob corresponding to FIGS.

FIG. 9 is an explanatory diagram showing a usage state of the present invention.

FIG. 10 is a control circuit diagram of a work machine lifting mechanism.

[Explanation of symbols]

(11) · Cover case (12) Lever guide groove (16) Rear wheel ender (17) Base plate (20) · Bolt (21) Natsu (22) ・ Position setting device (26) -Rotation axis (27) -Rotating arm (32) ・ Operating lever (34) · Support shaft (37) · Compression spring material (39) · Link piece (40) ・ Pivot pin (41) ・ Pivot pin (42) · Stopper plate (43) · Bolt (44) Natsuto (45) ・ Long hole (47) ・ Stopper knob (H) ... (L) ... (Β) ... Rotation angle range

Claims (2)

[Claims] 1. A U-shaped cross section having an opening on the back surface which is a mounting surface for the rear wheel ender (16) of the tractor,
In addition, a small and flat cover case (11) in which the lever lead-out guide grooves (12) are arranged on the arcuate body surface, and a base plate (17) fixedly supported inside the cover case (11) in an upright state, A volume type position setting device (22) assembled to the base plate (17) and a rotation shaft (22) of the position setting device (22) for setting the hanging height of the working machine towed by the tractor. 26) through a rotating arm (27) integrally extended upward and a fulcrum shaft (34) parallel to the rotating shaft (26) of the position setting device (22), and the lower end portion of the base plate (1).
7), which is pivotally attached to the pivot arm 7 and extends parallel to the rotating arm 27, and which is led out from the lever lead-out guide groove 12 of the cover case 11, and the position setting. In order to integrally rotate the rotating shaft (26) of the device (22) and the operating lever (32), the middle part of the operating lever (32) and the upper end of the rotating arm (27) are pivotally supported. A compression spring member (37) fitted to a fulcrum shaft (34) of the link piece (39) to be connected to the operation lever (32) so as to always apply a braking force to the link piece (39).
And a stopper plate (42) that is additionally joined and fixed to the base plate (17), and the operating lever is set so that the lifting height of the working machine is set to the maximum raised position (H). When (32) is raised,
The pivot pin (40) connecting the operating lever (32) and the link piece (39) is locked to the punching edge of the base plate (17), and also the working machine is at the lowest position (L). When the operation lever (32) is laid down, the pivot support pin (40) is engaged with the punching edge of the stopper plate (42), and the cover case (40) is 11) The rear of the rear wheel fender (1
An operation unit for controlling a working machine up and down in a tractor, which is configured to be used by being attached to an inner wall surface of 6) in a covered state. 2. A stopper plate (42) is integrally fastened to a base plate (17) by a plurality of bolts (20) (43) and nuts (21) (44), and one of the bolt receiving slots is provided. The mounting height of the stopper plate (42) with respect to the base plate (17) can be adjusted by opening the stopper plate (45) in the stopper plate (42) or the base plate (17). An operating unit for controlling the lifting and lowering of the work implement in the tractor according to 1.