JPH1084754A - Preprocessing part transmission mechanism for combine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preprocessing part transmission mechanism for a combine of simple constitution by surely holding the engaging position of the clutch pulley of a reaping clutch. SOLUTION: This combine is provided with a position detector 2P detecting the height position of a preprocessing part and with a reaping clutch 5 of a belt clutch system engaging and disengaging the transmission of the preprocessing part by the operation of the clutch puller part 50 to engage/ disengage the clutch pulley when the height of the preprocessing part is an install value. In this case, a supporting arm 51 supporting the clutch pulley 50 is pivotaly supported by a supporter 10 in the state capable of freely rocking and rotating, and the other end of the arm 51 and an operating gear 53 engaged with the motor shaft 5K1 of a driving motor 5M operated by the command of the detector 2P are connected by an operation rod 52 through a connection pin 5a and an operation pin 53a, then, at the time of switching the pulley 50 from a disengaging position to an engaging position, the connection pin 51a, the operation pin 53a and the fixing shaft 1G of the operation gear 53 are positioned nearly on a straight line to hold the clutch engaging position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-processing unit transmission mechanism for a combine.

[0002]

2. Description of the Related Art Conventionally, as a transmission mechanism of a pre-processing unit of a combine, for example, Japanese Utility Model Publication No. 6-18435 discloses a structure in which a pre-processing unit is provided on an airframe so as to be able to move up and down freely. The transmission of the section is performed by selectively switching between the clutch engagement position and the disengagement position by operating the clutch pulley of the belt clutch type mowing clutch, and the lifting and lowering operation of the preprocessing section and the operation of the clutch pulley are released. Via a linking mechanism including a wire and a relay swing arm, the cutting clutch is disengaged when the preprocessing unit is raised above a set amount, and the cutting clutch is engaged when the preprocessing unit is lowered below the set amount.

[0003]

However, as in the configuration described in the above-mentioned publication, a device for linking an automatic lift shut with a wire or a link arm has a problem in that the wire is stretched during a long-term use, and a link or the like accompanying the wire is stretched. There is a disadvantage that the backlash tends to occur, and a complicated adjustment operation is required to correct the backlash.

Further, when the clutch pulley is operated by elevating and lowering the pre-processing unit, and when the clutch pulley pushes and tensions the belt to maintain the in-position, it acts on wires and other members that are involved in the auto-lift shut. There is a disadvantage that the power is excessive. For this reason, there are problems such as the necessity of increasing the size of the constituent members or improving the strength more than necessary.

[0005]

SUMMARY OF THE INVENTION To solve the above-mentioned conventional problems, a pre-processing unit transmission mechanism of a combine according to the present invention comprises:
The pre-processing unit 2 is provided on the body 1 so as to be vertically movable,
A belt clutch type reaping clutch is provided which has a position detector 2P for detecting a height position of the pre-processing unit 2, and allows the transmission of the pre-processing unit 2 to be turned on and off by the operation of the clutch pulley 50. When the height of the pre-processing unit 2 is smaller than the set value, the clutch pulley 50 is engaged, and when the height of the pre-processing unit 2 is larger than the set value, the clutch pulley 50 is turned off. An intermediate portion of a support arm 51 that supports the pulley 50 is pivotally supported on a support 10 erected on the body 1 so as to be swingably rotatable, and is operated by a command from the other end of the support arm 51 and the position detector 2P. An operating gear 53 meshing with an output gear 5K of the driving motor 5M is connected to a connecting pin 51a and an operating pin 53a.
When the drive motor 5M rotates and the clutch pulley 50 is moved from the disengaged position to the engaged position, the connecting pin 51a and the operating pin 53 are connected.
a and the mounting shaft 1G of the operating gear 53 are kept substantially in a straight line so that the clutch engagement position is maintained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral A denotes a traveling machine 1 having a crawler-type traveling device 1a, which supports a pre-processing unit (cutting unit) 2 from the front so as to be able to move up and down by a configuration described later, A threshing section 3 is mounted, and a control panel section 4a and a driver's seat 4b are provided from the front side of the threshing section 3.
This is a combine in which a control section 4 composed of the above-mentioned components and a Glen tank 4c are installed behind the control section 4.

[0007] The pre-processing unit 2 includes a divider 21, a raising device 22, a cutting blade 23, and a cutting grain culm for cutting and raising the planted grain culm on the cutting frame 20, similarly to the conventional apparatus. It is constituted by a rear conveying device 25 and the like, which are formed by a conveying belt for adjusting the depth and the like, which is conveyed rearward and conveyed to the feed chain 30 of the threshing unit 3. As shown in FIG. 2, an input pulley 2N for transmitting power to these and a drive pulley 2K driven from the engine side, and a support frame 26 supporting the cutting frame 20 is driven by a rear drive pulley shaft 2G. The supporting shaft portion (fulcrum portion) 2S that is supported is rotatably supported by an upper metal portion 10a of a pillar 10 that is provided upright at the front of the traveling machine body 1. The support frame 26 and the traveling body 1
Is connected by a hydraulic cylinder 11 for raising and lowering shown in FIG. 8, so that the preprocessing unit 2 is raised and lowered to support the cutting height in an adjustable manner.

The pre-processing unit 2 includes a clutch pulley 50 in which a transmission belt 2V wound around an input pulley 2N and a driving pulley 2K is installed on a loose side thereof. The cutting clutch 5 is configured to be automatically operated and turned on (ON) and turned off (OFF) in conjunction with the manual operation and the cutting height of the preprocessing unit 2.

The pre-processing unit 2 operates an operation lever 40 provided on the control unit 4 to operate a switching valve (solenoid) 11a and a check valve (solenoid) 11b shown in the hydraulic circuit diagram of FIG. , Hydraulic cylinder 11
When the is extended and retracted, it can be moved up and down around the shaft support 2S. In the elevating operation, the cutting height, that is, the ascending position of the preprocessing unit 2 is detected by a position detector (lift potentiometer) 2P such as a potentiometer installed on the shaft support 2S or the like. Then, the auto lift shut switch 5S (FIG. 5,
When 7) is ON, when the cutting height becomes equal to or higher than the set cutting height H1, the drive motor 5M of the cutting clutch mechanism 5 is reversely rotated by this signal to lower the clutch pulley 50 to the state shown in FIG. The power of the processing unit 2 can be cut off. In FIG. 6, reference numeral 12 denotes a hydraulic pump, 13 denotes a side clutch cylinder for separately operating the left and right traveling devices 1a, 1a, and 14 denotes a brake cylinder.

Next, referring to FIGS.
Will be described. As shown in FIGS. 2 and 3, a support arm 51 supporting the clutch pulley 50 at a tip thereof is rotatably supported at an intermediate portion by a support 10 by a support shaft 10b, and is bracketed by a connection pin 51a protruding from the other end. 5
The operating rod 52 is connected via 1b. An operation gear 53 formed of a sector gear is supported on an attachment bracket 1c provided on the traveling body 1 via an attachment shaft 1G. The operation gear 53 is an output gear 5K which is axially mounted on the drive motor 5M via a speed reducer. Is engaged. And the operating gear 5
One end of an operation piece 55 is attached to an upper position on the outer periphery of 3 via an operation pin 53a, and is connected to the operation rod 52.

A compression spring 56 is connected between the operating rod 52 and the operating piece 55 so that the operating gear 53 presses the clutch pulley 50 against the transmission belt 2V with elastic force. Powered state. Then, an appropriate tension is applied to the transmission belt 2V so as to buffer the impact force while maintaining the tension transmission state. 51S
Reference numeral denotes a tension spring provided between the support arm 51 and the column 10, and urges the clutch pulley 50 in a downward direction. The mounting shaft 1G of the operation gear 53 is provided with an auto-lift shut sensor 5P (a sensor for detecting a position where the conduction of the pre-processing unit 2 is cut off or a position where the conduction is cut) for detecting a rotation angle of the operation gear 53,
When the operating gear 53 rotates and the clutch pulley 50 moves downward and separates from the transmission belt 2V to be in a clutch disengaged state, a rotation of a predetermined amount or more is detected. The pulley 50 moves up and the transmission belt 2V
Is pressed to detect the rotation to enter the clutch state, and the drive motor 5M is stopped by the signal.

The combine A having the pre-processing unit 2 is operated as desired by operating various operation switches and work operation levers. That is, as shown in FIG. 5 and FIG. 7, the above-mentioned operation lever 40 is provided upright on the front side of the control panel section 4a constituting the control section 4, and is tilted in the front-rear direction. 2 can be lowered and raised.

A cutting height release switch 40S is provided on the head of the operation lever 40, and when the switch is pressed, a cutting height setting switch 21S or the like is used to set a cutting height setting switch 21S or the like. The position control mode for regulating and adjusting the lowering position of the mechanism is released. Further, a main speed change lever 60, a reaping clutch lever (pre-processing unit lever) 61, and a work machine clutch lever (threshing unit lever) 62 are provided from the front side of the control panel unit 4a. A cutting clutch switch 61S (FIG. 7), which is turned on by this tilting operation, is provided at the base of the cutting clutch lever 61, and the drive motor 5M is actuated by the ON operation of the cutting clutch switch 61S, so that the clutch of the preprocessing unit 2 is turned on. I am trying to enter.

In this embodiment, the feed chain 30 provided along the handle of the threshing unit 3 is interlocked so as to operate in the same manner as the clutch on / off of the pre-processing unit 2, and is connected to the threshing unit. The on / off operation of 3 is performed by turning on / off the working machine clutch switch 62S installed at the base thereof based on the operation of the working machine clutch lever 62.

In addition, the above-mentioned switches and dials and the driving motor 5M, etc., other than the dial are circuit-structured in the microcomputer unit 1M shown in FIG. 7, and the operating switches are arranged in the control unit 4 in the arrangement shown in FIG. ing. The combine A having the above configuration operates the main body lever 60 and the like to drive and operate the machine body 1 and also operates the reaping clutch lever 61.
By operating the work machine clutch lever 62 and
The switches 61S and 62S are turned on to drive the pre-processing unit 2 and the threshing unit 3. By operating the operation lever 40 to raise and lower the pre-processing unit 2 up and down, the threshing can be performed while cutting the planted cereal stem to a desired height while steering the machine body 1.

At this time, the cutting height position switch 21
When S is ON, the preprocessing unit 2 adjusts the cutting height set and adjusted by the cutting height setting dial 21D (FIGS. 5 and 7), that is,
The grain stalk can be cut to a predetermined height adapted to the condition of the field in accordance with the cutting height position HP schematically shown in FIG. And the auto lift shut switch 5S is set to O
N, the pre-processing unit 2 is raised when the body is turned or the like, and an operation is performed so that the reaping clutch is disengaged.

When the position detector 2P detects that the pre-processing unit 2 has risen to a predetermined height H1 or more, the drive motor 5M is reversed to lower the clutch pulley 50 via the cutting clutch 5, and The transmission of the processing unit 2 is automatically turned off. When the pre-rotational traveling is completed and the pre-processing unit 2 is lowered to the cutting height H2 or less again, the position detector 2P rotates the driving motor 5M forward to drive the clutch pulley via the cutting clutch 5. The combine operation can be simply and efficiently performed by pushing up the upper part 50 and automatically setting the transmission of the pre-processing unit 2 to be engaged.

When the drive motor 5M rotates forward from the "clutch disengaged state" shown in FIG. 2, the operating gear 53 rotates around the mounting shaft 1G by the output gear 5K. Actuated, the operating pin 53
a, the support arm 51 is rotated (rotated clockwise) so as to be pulled down around the support shaft 10b via the operation piece 55, the operation rod 52, and the connection pin 51a, and the clutch pulley 50 is moved to the position shown in FIG.
As a result, the clutch pulley 50 tensions the loose side of the transmission belt 2V to bring the clutch into the engaged state.

In this case, the connecting point of each link member, that is, the connecting pin 51a, the operating pin 53a, and the mounting shaft 1G of the operating gear 53 are "substantially on a straight line" in the clutch engagement position of the clutch pulley 50. It is set to be. Accordingly, the reaction force or impact that the clutch pulley 50 receives from the transmission belt 2V during transmission acts on the reaping clutch 5 toward the mounting shaft 1G of the operation gear 53, so that the operation gear 53 and the output gear 5K which is a pinion gear. There is no or little force to rotate.
As a result, since the force resulting from the reaction force can be stably received, the operation gear 53 and the output gear 5
It does not give an excessive load or rattle to the K and the deceleration mechanism or the like built in the drive motor 5M.

In addition, it is possible to prevent vibration and rattling of the link system of the member and to perform good clutch transmission. Therefore, there is an advantage that the weight can be reduced with a simple configuration without increasing the size of the constituent members. The pre-processing portion transmission mechanism of the combine that performs the above-described operation is roughly controlled by the flowcharts shown in FIGS. 9 to 11, and controls the on / off control of the reaping clutch 5 based on “hysteresis judgment” as a criterion. By controlling and operating the drive motor 5M of the mechanism 5, it is possible to more conveniently operate and perform high-performance work efficiently.

FIG. 9 is a main flowchart of the control circuit, which is composed of a flow of a "reaching clutch" and a flow of an "auto lift shut". FIG. 10 shows the “cutting clutch” (S
FIG. 11 shows a flow chart of 1), and FIG. 11 shows ON / OF of the cutting clutch 5 in consideration of the hysteresis (β) of the cutting height.
The flowchart of "Auto Lift Shut" (S2) for issuing an F command and for starting and stopping the feed chain clutch motor is shown. FIG. 12 shows a timing chart of the automatic lift shut.

In the sub-flowchart of FIG. 10, ON / OFF (I11) of the reaping clutch switch 61S (FIG. 7),
Check ON / OFF of auto lift shut switch 5S (adoption / non-adoption of auto lift shut mode) (I12) and ON / OFF command by auto lift shut mode when ON (adopted) (I13, I14) The mowing clutch 5 is turned ON (S12) or OFF (S14).
In the direction of rotation.

This flow will be described in detail below. In the sub-flowchart of the "reaching clutch" (S1), first, the O
N / OFF is determined (I11), and if ON, and the auto-lift shut mode is not adopted (I12) or the auto-lift shut mode is adopted (I12) and the cutting clutch ON command is issued (I13) ), The clutch OFF timer is confirmed to be zero (I15), the clutch ON timer is started (S11), and then the drive motor 5M is turned on.
Until the limit on the side is exceeded (I17), it is rotationally driven in the ON direction (S12).

The cutting clutch switch 61S is turned off.
In the case of F (I11) and the case where the cut-off clutch OFF command is issued by the auto lift shut mode switch ON (I12)
In (I14), it is confirmed that the clutch ON timer is zero (I16), and the clutch OFF timer is started (S1).
From (3), the drive motor 5M is rotationally driven in the OFF direction until the drive motor 5M exceeds the limit on the OFF side (I18) (S14).

Further, when the clutch ON timer (I16) and the clutch OFF timer (I15) are not zero and the drive motor 5M must not be driven immediately, or when the limit in each drive direction is exceeded (I17, I18) ) Or, if the auto lift shut switch is ON (I12) but neither the ON command (I13) nor the OFF command (I14) is issued, the drive motor 5
M is stopped (S15).

Here, the clutch ON / OFF timer (I1
6, I15) prevents the drive motor 5M from changing its rotation direction by a short-time command change,
The limits (I17, I18) of the drive motor 5M prevent the operation gear 53, which is a sector gear, from being disengaged from the drive gear 5K, and perform ON / OFF positioning of the clutch.

Next, in the sub-flowchart of FIG. 11, ON / OFF (I21) of the reaping clutch switch 61S and ON / OFF (I22) of the auto lift shut switch 5S are determined, and further, the ON of the reaping clutch switch 61S is turned on.
If the auto-lift shut mode is adopted in the state (I22), the cutting clutch ON / OFF command is issued while using the cutting height hysteresis as a judgment material (S28, S28).
23) Then, the feed chain clutch motor is rotationally driven in a direction in which the feed chain 30 is turned on (S29) or turned off (S24).

This flow will be described in detail below. First, the setting of the hysteresis flag in this sub-flowchart shown in FIG. 11 will be described. This hysteresis flag is
This is a mark for knowing whether the height of the pre-processing unit 2 is higher than H1 or lower than H2 when the time goes up, and by this, the cutting clutch 5 and the feed chain 30 are turned on. -The OFF direction is determined.

More specifically, when the height of the pre-processing unit 2 experiences a state higher than H1 after the automatic lift shut switch is turned ON (I23), it is set to H (S21).
, H2 (I24), it is set to L (S26). Then, when the auto lift shut switch is turned off (I22), it is reset (S31). In the sub-flowchart of "auto lift shut" shown in FIG. 11, first, the reaping clutch switch 61S (I21) and the auto lift shut switch 5S (I22) are turned on,
Further, when the pre-processing unit 2 rises above the height H1 and the hysteresis flag is set to H, the automatic lift O
After confirming that the N timer is zero (I27), the auto-lift off timer is started (S22), and then a cutting clutch OFF command is issued (S23), and a cutting clutch sensor for detecting the upper and lower limits of the cutting clutch. After confirming that the detected value of 5P is smaller than (OFF limiter + α1) (I29) (that is, confirming that the cutting clutch is completely disengaged), until the feed chain clutch motor exceeds the limit on the OFF side ( I31) Drive (S24).

The cutting clutch switch 61S (I21)
And auto lift shut switch 5S (I22) are ON
Further, when the pre-processing unit 2 falls below the height of H2 and the hysteresis flag is set to L, it is confirmed that the auto lift OFF timer is zero (I28), and After starting (S27), the detected value of the feed chain clutch sensor becomes (ON limiter
α2) is larger than (I30) only (that is, before the feed chain clutch is engaged), a cutting clutch ON command is issued (S28) until the feed chain clutch motor exceeds the ON-side limit ( I32) Drive
(S29).

The cutting clutch switch 61S (I1
1) is OFF or auto lift shut switch 5
When S (I12) is OFF, the ON and OFF commands of the auto-lift shut mode of the reaping clutch 5 are released (S3
0), and further resets the hysteresis flag (S31),
After checking the zero of the auto lift OFF timer (I26), the feed chain clutch motor is driven until the ON side limit is exceeded (I32) (S29).

If the hysteresis flag is reset (I25) or the auto-lift ON timer (I27) or the auto-lift OFF timer (I26, I28) is not zero and the feed chain clutch motor is driven immediately, If not,
When the limit in each drive direction is exceeded (I31, I32), and when the detection value of the reaping clutch sensor 5P is larger than the OFF limiter + α1 (I29), the feed chain clutch motor is stopped (S25). Here, auto lift ON / OFF
The timer serves to prevent the feed chain clutch motor from changing its rotation direction in a complicated manner due to a short-time command change.

A part of the control based on this flow will be described with reference to the time chart of FIG. In this figure, when both the reaping clutch switch (lever) and the auto lift shut switch (lever) are turned on to set the auto lift shut mode, the cutting height of the pre-processing unit 2 changes as shown in FIG. 12, for example. The control state of the drive motor of the reaping clutch and the reaping clutch at this time is shown.

First, when the preprocessing unit 2 becomes (A), the flag is set to L, and the mowing clutch drive motor 5M is turned off.
Drive to the N side to turn on the reaping clutch. Next, when the preprocessing unit 2 passes through (D) and becomes higher than H1, the flag is set to H, and the mowing clutch drive motor 5M is turned off.
Drive to the FF side to turn off the reaping clutch. Furthermore, even if the pre-processing unit 2 passes through (e) and becomes lower than H1 in (f), it does not pass through H2, so the flag is H and the ON drive is not performed.

Then, in (h), when the pre-processing unit 2 becomes lower than H2, the flag is set to L, the mowing clutch drive motor 5M is driven to the ON side, and the mowing clutch is turned on.
To After that, even if the pre-processing unit 2 becomes higher than H2 again, since the preprocessing unit 2 does not pass through H1, the flag becomes L.
No OFF drive is performed. Thus, by the control according to the flowcharts shown in FIGS. 9 to 11 described above,
When the pre-processing unit 2 experiences H1 or more and becomes H2 or less, the automatic control of the auto-lift shut that turns on the cutting clutch when the preprocessing unit 2 becomes H2 or more and experiences H2 or less and then becomes H1 or more is obtained. .

As shown in FIG. 7, the control operation of the mowing clutch 5 having the automatic lift shut function is such that the switches and the position detectors are connected to the microcomputer unit 1M, and the microcomputer unit 1M is connected to the microcomputer unit 1M shown in FIG. 11 are programmed to perform the determination and the operation in accordance with the flowcharts shown in FIGS. As shown in FIG. 8B, the cutting height of the reaping clutch 5 is H1 = H2 +
β, the entry height of the mowing clutch mechanism 5 is H2. Here, H2 is a height automatically set by the cutting height setting dial 21D, and β is a constant of a hysteresis range.

Therefore, if the reaping clutch switch 61S (FIG. 7) and the automatic lift shut switch 5S are turned on during the combine operation, the preprocessing unit 2 can perform the reaping operation at a height of H2 or less. Then, when the pre-processing unit 2 is lifted when the body turns, the position detector 2P that detects the movement of the support frame 26 when the body starts moving up.
Emits a signal corresponding to the height, and if it is determined in the above program that the cutting height is greater than the cutting height H1, after a hysteresis upper limit determination command, and after an appropriate time by the timer circuit, the cutting clutch OFF command is issued. , Drive motor 5M
Is operated to reverse the rotation of the drive motor 5M to disconnect the cutting clutch 5. In this state, the vehicle stops at a position slightly higher than the cutting height H1.

Further, when the turning of the machine body is terminated, the cutting clutch 5 is disengaged, and the pre-processing section 2 is gradually lowered from a position slightly higher than H1, and the cutting operation is performed again, the lowering of the operating lever 40 is performed. The pre-processing unit 2 is moved down by operation. When the preprocessing unit 2 reaches the lower H2 height that has passed the H1 height, the preprocessing unit 2 determines that the value emitted from the position detector 2P is smaller than H2, and rotates the drive motor 5M in the normal direction to make the aforementioned rotation. Thus, the mowing clutch 5 can be turned on.

With the above configuration, the combine that performs the on / off operation of the reaping clutch 5 by making a hysteresis determination in accordance with the elevating operation of the preprocessing unit 2 has a height H1 at which the preprocessing unit 2 is raised and the reaping clutch 5 is disengaged. Since the height H2 at which the pre-processing unit 2 is lowered and the mowing clutch 5 enters is shifted from the hysteresis range by β, for example, an unskilled worker performs pre-processing when turning the machine. Even if the part 2 is raised or lowered to a halfway position,
The set state can be roughly maintained. Therefore,
Even if the pre-processing unit 2 swings up and down due to the vibration of the machine body and the unevenness of the ground, it is possible to prevent the cutting clutch 5 from being inadvertently turned on and off unlike the conventional one, and it is possible to smoothly perform the operation. The combine operation can be performed with good operability.

The on / off operation of the mowing clutch 5 by the control in which the hysteresis determination criterion is entered is performed by a conventional combine using the existing mowing height setting dial 21D, the mowing height position switch 21S and the like.
Since the operation is performed for each of the set heights, there is an advantage that the automatic lift shut-off mechanism can be provided at a low cost.

[0041]

When the clutch pulley is operated from the disengaged position to the engaged position by the rotation of the drive motor, the clutch pulley connects the connecting pin and the operating pin for connecting the support arm and the operating portion via the operating rod. The clutch is engaged and the engaged position is maintained while changing the posture so as to be arranged substantially linearly with the mounting shaft of.

Therefore, the drive motor system having the above structure does not need to increase the durability more than necessary against the load at the time of the transmission of the clutch pulley, and the clutch motor can hold the clutch pulley even for the speed reduction mechanism of the drive motor. Since the load at the time can be reduced, there is an advantage that the pre-processing unit transmission mechanism of the combine which can reduce the size and simplification of the drive motor can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a combine.

FIG. 2 is a side view showing a disengaged state of the reaping clutch.

FIG. 3 is a back sectional view showing a main part of FIG. 2;

FIG. 4 is a side view showing an engaged state of a reaping clutch.

FIG. 5 is a perspective view of a control unit.

FIG. 6 is a hydraulic circuit diagram.

FIG. 7 is an electric circuit diagram.

8A is a schematic diagram of a preprocessing unit, and FIG. 8B is an operation diagram of FIG.

FIG. 9 is a flowchart of a control circuit.

FIG. 10 is a flowchart of a part of the control circuit in FIG. 9;

FIG. 11 is a flowchart of a part of the control circuit in FIG. 9;

FIG. 12 is a timing chart.

[Explanation of symbols]

Reference Signs List 1 traveling body (machine stand) 1G mounting shaft 2 preprocessing unit 2P position detector 5 mowing clutch 5M drive motor 5K1 motor shaft 5S auto lift shut-off switch 10 support 21D cutting height setting dial (cutting height setting mechanism) 50 clutch pulley 51 Support Arm 51a Connecting Pin 53 Operating Gear 53a Operating Pin 61S Cutting Clutch Switch

Claims (1)

[Claims] 1. A pre-processing unit 2 is provided on a body 1 so as to be vertically movable, and has a position detector 2P for detecting a height position of the pre-processing unit 2. The transmission of the pre-processing unit 2 is performed by a clutch pulley 50. The clutch pulley 50 is engaged when the height of the pre-processing unit 2 is less than or equal to a set value, and the height of the pre-processing unit 2 is higher than a set value. In a combine which operates so that the clutch pulley 50 is disengaged when it is large, a middle part of a support arm 51 which supports the clutch pulley 50 is pivotally supported on a support 10 erected on the body 1 so as to be swingably rotatable. Then, the other end of the support arm 51 and the operation gear 53 meshing with the output gear 5K of the drive motor 5M operated by the command of the position detector 2P are connected via the connection pin 51a and the operation pin 53a. When the drive motor 5M rotates and the clutch pulley 50 is shifted from the disengaged position to the engaged position, the connecting pin 51a is substantially linearly connected to the operating pin 53a and the mounting shaft 1G of the operating gear 53. The pre-processing unit transmission mechanism of the combine that is located above and holds the position where the clutch is engaged.