JPH07238834A - Normal/reverse operation change-over structure for fan of radiator - Google Patents

Abstract

PURPOSE:To let a change-over member be accurately suspended at its normal and reverse operating positions in the normal/reverse operation structure for the fan of a radiator where the change-over member of a belt transmission system for normal/reverse operating pulleys is so constituted that a changeover for the normal/reverse operations of the fan can be freely made with an electrically driven actuator actuated to normal/reverse operating positions. CONSTITUTION:A speed sensor 28 is provided, which detects the operating speed of a change-over member 16, based on a judgement that the change-over member 16 reaches a normal operation position or a reverse operation position when the detected valve of a speed sensor 28 is less than a specified value because of resistance by a belt transmission system 14 and 19, operating current is shut off, so that an electrically driven actuator is thereby suspended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / reverse switching structure of a fan for guiding a cooling outside air to a radiator in a radiator mounted on a work vehicle.

[0002]

2. Description of the Related Art An example of a forward / reverse switching structure for a radiator fan as described above is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 5-52243. In this structure, a normal rotation power that drives the fan in the normal direction so that the outside air is sucked through the radiator and air flows in the reverse direction to a radiator fan (6 in FIG. 1 of the above publication) that can freely rotate in the normal direction. As described above, the belt drive system (12 and 16 in FIG. 1 of the above publication) is provided which can selectively transmit the power for reverse rotation for driving the fan in reverse. The forward rotation pulley (1 in FIG. 1 of the above publication)
3) is operated to the transmission position, and the reverse rotation pulley (14 in FIG. 1 of the above publication) is operated to the transmission cut-off position so that the forward rotation power is transmitted and the forward rotation pulley. A switching member (24 in FIG. 1 of the above publication) which is movable to a reverse rotation position for operating the reverse rotation pulley to the transmission position and operating the reverse rotation pulley to transmit the reverse rotation power is provided. An electric actuator (C in FIG. 1 of the above publication which can freely move the switching member to the forward rotation position side and the reverse rotation position side)
Y).

As a result, in a normal state, the fan is driven in the normal direction so that the outside air is sucked through the radiator, and the fan is sometimes driven in the reverse direction to remove dust and the like adhering to the surface of the radiator and the dustproof mesh for the radiator. Blow away. In this case, in a state where the switching member is located at the forward rotation position, an operating current to the reverse rotation position side is supplied to the electric actuator only for a set time so that the electric actuator operates the switching member to the reverse rotation position. On the contrary, while the switching member is in the reverse rotation position, the operation current to the forward rotation position side is supplied to the electric actuator only for the set time,
The switching member is operated to the normal position by the electric actuator.

[0004]

As described above, when the switching member is configured to move between the forward rotation position and the reverse rotation position depending on the supply time of the operation current to the electric actuator, the electric actuator is provided. If the positional relationship between the switch member and the switching member is once displaced due to mechanical backlash, etc., while repeating the movement operation to the forward rotation and reverse rotation positions,
In some cases, the difference in the positional relationship between the electric actuator and the switching member is enlarged, and the electric actuator may not be able to accurately move the switching member to the forward rotation position and the reverse rotation position.
According to the present invention, in the forward / reverse switching structure for a fan for a radiator, even if the switching member is repeatedly moved to the forward and reverse positions by the electric actuator, the switching member can be accurately moved to the forward and reverse positions. It is intended to be configured as.

[0005]

The feature of the present invention resides in the following structure in the forward / reverse switching structure of the fan for radiator as described above. In other words, [1] a forward fan that can freely rotate forward and backward, a forward rotation power that drives the fan forward by a forward rotation pulley so that outside air is drawn in through the radiator, and a reverse rotation pulley that causes air to flow in the opposite direction. With a belt transmission system that can selectively transmit the power for reverse rotation that drives the fan in reverse by operating the forward rotation pulley to the transmission position and the reverse rotation pulley to the transmission cut-off position. The forward rotation position where the transmission is transmitted and the forward rotation pulley to the transmission blocking position and the reverse rotation pulley to the transmission position,
An electric actuator that includes a switching member that is movable to a reverse position that allows reverse rotation power to be transmitted, and that is operable to move the switching member to a forward rotation position side and a reverse rotation position side, and an electric actuator based on an operation command. When the detection value of the speed sensor becomes equal to or less than the set value, the switching member is provided with a control means for supplying an operating current to the forward rotation position side and the reverse rotation position side, and a speed sensor for detecting the operation speed of the switching member. A stop means is provided for stopping the electric actuator by interrupting the operation current to the electric actuator.

[2] Forward rotation power for driving the fan in the forward direction by the forward rotation pulley so that the outside air is sucked into the radiator fan that can freely rotate in the forward and reverse directions.
With a belt drive system that can selectively transmit the power for reverse rotation that drives the fan in reverse by a pulley for reverse rotation so that air flows in the opposite direction, operate the pulley for forward rotation to the transmission position to set the pulley for reverse rotation. Operate to the transmission cut-off position so that the normal rotation power is transmitted, and operate the forward rotation pulley to the transmission cut-off position and the reverse rotation pulley to the transmission position to transmit the reverse rotation power. The electric actuator includes a switching member movable to the reverse position so that the switching member can be operated to move the switching member to the forward rotation position side and the reverse rotation position side, and the forward rotation position of the switching member to the electric actuator based on the operation command. And a control means for supplying an operating current to the reverse position and a speed sensor for detecting the operating speed of the electric actuator, and the detected value of the speed sensor is equal to or less than a set value. It comes to, are provided with a stop means for stopping the electric actuator to interrupt the operation current to the electric actuator.

[3] Forward rotation power for driving the fan in the forward direction by the forward rotation pulley so that the outside air is sucked into the radiator fan that can freely rotate in the forward and reverse directions.
With a belt drive system that can selectively transmit the power for reverse rotation that drives the fan in reverse by a pulley for reverse rotation so that air flows in the opposite direction, operate the pulley for forward rotation to the transmission position to set the pulley for reverse rotation. Operate to the transmission cut-off position so that the normal rotation power is transmitted, and operate the forward rotation pulley to the transmission cut-off position and the reverse rotation pulley to the transmission position to transmit the reverse rotation power. The electric actuator includes a switching member movable to the reverse position so that the switching member can be operated to move the switching member to the forward rotation position side and the reverse rotation position side, and the forward rotation position of the switching member to the electric actuator based on the operation command. Side and reverse rotation position side, and a rotation speed sensor for detecting the rotation speed of the fan, and a rotation speed sensor for detecting the rotation speed of the fan. Reached when, are provided with a stop means for stopping the electric actuator to interrupt the operation current to the electric actuator.

[0008]

[Action]

[I] With the configuration of [1] or [2] above, when the electric actuator is used to move the switching member from the forward rotation position to the reverse rotation position based on the operation command, the switching member moves to the reverse rotation position side. When the pulley for reverse rotation starts to act on the belt transmission system when approaching, the tension of the belt transmission system starts to be applied as a resistance to the switching member and the electric actuator. As a result, the operating speed of the switching member to the reverse rotation position side (the operating speed of the electric actuator) decreases due to the resistance from the belt transmission system, so the operating speed of the switching member to the reverse rotation position side (the operating speed of the electric actuator). ) Drops below the set value, the switching member reaches the reverse rotation position and the reverse rotation pulley acts on the belt transmission system with sufficient force.
It can be determined that the fan has reached the state where it is normally driven in reverse. Therefore, if the operating current to the electric actuator is cut off based on this, the switching member and the electric actuator stop accurately at the reverse rotation position.

When detecting the operating speed of the switching member (the operating speed of the electric actuator), the position of the switching member (electric actuator) is detected by a potentiometer or the like, and the detected value is differentiated to perform the switching member (electric actuator). ) May be configured to obtain the operating speed. Therefore, with this configuration, the current position of the switching member (electric actuator) can be grasped. Therefore, if the forward rotation and reverse rotation positions are roughly known in advance, the switching member (electric actuator) will rotate forward and backward. The operating speed has dropped to below the set value as described above after reaching the reverse position, or the operating speed is below the set value at the intermediate position between the forward and reverse positions as described above. It is possible to determine whether or not it has decreased. In this case, the switching member (electric actuator) is not stopped at an intermediate position except in a special state, so that the switching member (electric actuator) operates at the intermediate position between the forward rotation and reverse rotation positions as described above. When is lower than the set value, it can be determined that the operating speed of the switching member is lowered due to some abnormality.

[II] When configured as in the above item [3],
For example, when the electric actuator is used to move the switching member from the forward rotation position to the reverse rotation position based on the operation command, when the switching member approaches the reverse rotation position side and the reverse rotation pulley starts to act on the belt transmission system, The power for reverse rotation begins to be transmitted to the fan via the transmission system. This allows
Since the fan starts to be driven in reverse by the power for reverse rotation from the belt transmission system, the rotation speed for reverse rotation of the fan increases,
When the reverse rotation speed of the fan reaches the reverse rotation setting speed, the switching member reaches the reverse rotation position and the reverse rotation pulley acts on the belt transmission system with sufficient force, and the fan is normally driven in reverse rotation. It can be judged that it has reached. Therefore, if the operating current to the electric actuator is cut off based on this, the switching member and the electric actuator stop accurately at the reverse rotation position.

[0011]

According to the first or second aspect of the present invention, the electric actuator is stopped based on the increase in the resistance from the belt transmission system for the fan, so that the fan is normally driven in the normal and reverse directions. It becomes possible to stop the switching member and the electric actuator at a certain position (forward rotation and reverse rotation positions), and even if the switching member is repeatedly moved to the forward rotation and reverse rotation positions by the electric actuator, the switching member remains open. It became possible to accurately move to the forward rotation and reverse rotation positions, and the forward / reverse switching performance of the fan could be improved. Further, according to the first aspect or the second aspect, it is possible to easily detect a state in which the switching member (electric actuator) stops at the intermediate position between the forward rotation and the reverse rotation due to some abnormality. A structure that prevents overheating due to continuing operation of the engine with the switching member stopped at the intermediate position and the fan also stopped can be easily obtained.

According to a third aspect of the present invention, the electric actuator is stopped on the basis of the increase in the rotational speed of the fan, so that the fan is normally driven in the normal and reverse directions (normal and reverse positions). The switching member and the electric actuator can now be stopped with the electric actuator, and even if the switching member is repeatedly moved to the forward rotation and reverse rotation positions by the electric actuator, the switching member is accurately moved to the forward rotation and reverse rotation positions. It became possible to operate it, and the forward / reverse switching performance of the fan could be improved. Further, in claim 3, since the rotation speed of the fan itself is detected, it is more accurate whether the switching member reaches the position where the fan is normally driven in the normal rotation and the reverse rotation (normal rotation and reverse rotation position). Therefore, it is possible to further improve the forward / reverse switching performance of the fan.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a threshing device 2 is provided at the rear of the machine supported by a pair of left and right crawler type traveling devices 1, a mowing section 3 is provided at the front of the machine, and a driving section 4 is provided at the rear right side of the mowing section 3. Are arranged to form a combine for harvesting and harvesting grain. As shown in FIG. 1 and FIG. 2, the bonnet 6 covering the engine 5 is provided with the cockpit 7 for the driving section 4 on the upper part,
Inside the bonnet 6, a radiator 8 and a fan 9 for the engine 5 are arranged.

Next, the drive structure of the fan 9 for the radiator 8 will be described. As shown in FIGS. 3, 6 and 8, a pulley 11 is fixed to a rotary shaft 10 supported on a side surface of the engine 5, and the pulley 11, the output pulley 12 of the engine 5 and the input pulley 13a of the alternator 13 are extended, The first transmission belt 14 (corresponding to a belt transmission system) is wound. As shown in FIG. 8, the support arm 15a is swingably supported around the horizontal axis P3 of the case of the alternator 13, and the tension pulley 15 is provided at the tip of the support arm 15a. A spring 15b that urges the transmission belt 14 side is connected. As a result, the tension pulley 15 is constantly pressed against the outer surface of the first transmission belt 14.

A switching member 16 having a flat plate shape and a triangular shape is swingably supported on the rotating shaft 10, and a normal rotation pulley 17 having two pulleys stacked on the switching member 16 and two pulleys.
A reversing pulley 18 which is like a stack of sheets is supported. The fan 9 is rotatably supported by bearings on the pulley 11 of the rotating shaft 10, and the input pulley 9a is formed at the base of the fan 9. The input pulley 9a and the switching member 16 are used for normal rotation and reverse rotation pulleys 17 and 18 respectively. The second transmission belt 19 (corresponding to a belt transmission system) is wound over the entire length. As shown in FIGS. 6 and 9, the switching member 1
A forward rotation pulley 17 is supported by a support shaft 17a fixed to the shaft 6. On the other hand, the support shaft 18a of the reverse rotation pulley 18 is supported by the bolt 21 and the bracket 22 along the long hole 16a of the switching member 16 so that the position of the support shaft 18a can be adjusted. Is configured to be able to be finely adjusted.

With the above structure, the output pulley 12 and the first transmission belt 14 are constantly rotating in the direction of the arrow shown in FIG. The switching member 16 is moved to the forward rotation position A shown in FIG.
When it is rocked, the forward rotation pulley 17 is pressed against the inner surface of the first transmission belt 14 from the right side of the drawing, and the power of the first transmission belt 14 is increased by the forward rotation pulley 17 and the second transmission belt 1.
It is transmitted to the input pulley 9a through the input pulley 9a as a normal rotation power, and the fan 9 and the input pulley 9a are driven to rotate in the clockwise direction on the paper surface of FIG. In the state in which the fan 9 is normally driven in this way, the outside air serves as cooling air due to the suction action of the fan 9 as shown by the solid line arrow in FIG. 2 and passes from the dustproof net 20 of the bonnet 6 through the radiator 8 to the engine 5 side. This is the normal state.

On the contrary, when the switching member 16 is oscillated to the reverse rotation position B shown in FIG. 4, the reverse rotation pulley 18 is pressed against the outer surface of the first transmission belt 14 from the left side of the drawing, and the power of the first transmission belt 14 is increased. Is transmitted as a power for reverse rotation to the input pulley 9a through the reverse rotation pulley 18 and the second transmission belt 19, and the fan 9 and the input pulley 9a are reversely driven in the counterclockwise direction of FIG. In this manner, when the fan 9 is driven in the reverse direction, the air flows in the opposite direction to the above by the blowing action of the fan 9 as shown by the double-dashed line arrow in FIG. 2, and the surface of the radiator 8 and the dustproof net 20 ( Dust and the like adhering to the lower side) is blown off.

Next, the structure of the swinging operation of the switching member 16 for the fan 9 will be described. As shown in FIGS. 6 and 8, a disc-shaped first winding member 23 is rotatably supported around the axis P1 at a position different from the rotation shaft 10 of the switching member 16, and the first winding member 23 is rotated. Motor 24 for rotating
(Corresponding to an electric actuator), and the semi-disc-shaped second winding member 25 is also fixed to the switching member 16. The wire 26 connected to the pin 23 a of the first winding member 23 is wound around the second winding member 25 and connected to the support shaft 17 a of the switching member 16, and the pin of the first winding member 23. A spring 27 is connected across 23a and the switching member 16.

The state shown in FIG. 6 is the first winding member 23.
Is positioned at an angle corresponding to the forward rotation position A of the switching member 16, the pulling action of the spring 27 causes the switching member 16 to swing to the forward rotation position A, and the fan 9 is normally driven. Is in a state of being in contact (see FIG. 3). In this state, the wire 26 slightly sags, and the biasing force of the spring 27 and the tension of the first transmission belt 14 are balanced. In this case, the spring 27 and the pin 23a cause the axis P1 of the first winding member 23 to move.
The first winding member 23 is about to be rotated clockwise in the drawing by the urging force of the spring 27, and a stopper 29 for stopping the first winding member 23 at the angle shown in FIG. 6 is provided. Therefore, the first winding member 23 is held at the angle shown in FIG. 6 by the urging force of the spring 27 and the action of the stopper 29.

Next, when the motor 24 drives the first winding member 23 to rotate counterclockwise by approximately 180 ° in the drawing, the wire 26 is pulled while being wound by the first winding member 23, and the switching member. 16 and the second winding member 25 are also swung counterclockwise in the drawing, the switching member 16 is swung to the reverse rotation position B as shown in FIG. 7, and the fan 9 is reversely driven (see FIG. 4). . As shown in FIGS. 6 to 7, when the switching member 16 is swung from the forward rotation position A to the reverse rotation position B, the spring 27 is pulled toward the switching member 16 as the switching member 16 swings. At the same time, the pin 23a of the first winding member 23 to which the spring 27 is connected also moves to the switching member 16 side (first winding member 2).
Therefore, the spring 27 does not have a great resistance to the swinging operation of the switching member 16 from the forward rotation position A to the reverse rotation position B.

On the contrary, as shown in FIG. 7, the first winding member 2
When the motor 24 drives the first winding member 23 to rotate clockwise by about 180 ° in the state in which 3 is positioned at the angle corresponding to the reverse rotation position B of the switching member 16, the wire 26 is first wound. 6 is drawn out from the member 23, the spring 27 is pulled by the movement of the pin 23a, and the urging force of the spring 27 causes the switching member 16 and the second winding member 25 to swing counterclockwise in the drawing, as shown in FIG. Thus, the switching member 16 is rocked to the forward rotation position A.

Next, a cycle for swinging the switching member 16 to the reverse position B shown in FIGS. 4 and 7 will be described. In this cycle, as shown in FIG. 5, the switching member 16 is first held in the forward rotation position A only for the set time T2,
Next, the switching member 16 is swung from the forward rotation position A to the reverse rotation position B over the set time T4, and power does not flow to the fan 9 during this period. Then, the switching member 16 is held at the reverse rotation position B for the set time T3, and then the set time T
The switching member 16 is oscillated from the reverse rotation position B to the normal rotation position A over 4 to complete one cycle of the cycle T1.

In the above cycle, the fan 9
Is attached to the surface of the radiator 8 shown in FIG. 2 (the surface on the left side of the paper surface of FIG. 2) by once shutting off the power to the fan 9 from the state of being normally driven (see the neutral position in FIG. 5). Large dust and the like are dropped below the radiator 8 and the dustproof net 20 by the vibration of the machine body. Then, by driving the fan 9 in the reverse direction, the dust and the like adhering to the surface of the radiator 8 is blown off and dropped below the radiator 8 and the dustproof net 20. Blow it away. As shown in FIG. 5, the switching member 16 moves from the forward rotation position A to the reverse rotation position B (or vice versa).
The set time T4 in which the switching operation is performed and the set time T3 in which the switching member 16 is held in the reverse rotation position B have substantially the same length, and the set time T2 in which the switching member 16 is held in the forward rotation position A is The time is set to be sufficiently longer than the set times T3 and T4 described above.

Next, the switching member 16 is cycled in the cycle shown in FIG.
A flow for swinging the to the reverse rotation position B will be described. As shown in FIG. 6, a rotary potentiometer 28 (corresponding to a speed sensor for the switching member 16) is fixed to a lateral side surface of the engine 5, and the potentiometer 28 is provided.
A roller 28a made of rubber is fixed to the rotary detection shaft of, and the roller 28a is abutted on the outer peripheral surface of the second winding member 25. As a result, the swing position of the switching member 16 is continuously detected by the detection value of the potentiometer 28, and the operating speed of the switching member 16 is continuously detected by differentiating the detection value of the potentiometer 28. It

As shown in FIG. 5, with the forward rotation position A of the switching member 16 as the first reference (time point C1), the operating current is not supplied to the motor 24 until the set time T2 elapses,
The switching member 16 is held at the normal rotation position A. Switching member 16
When the set time T2 elapses in the state in which the motor is located at the forward rotation position A (time C2), the operation current to the reverse rotation position B side starts to be supplied to the motor 24, and the motor 24 and the wire 26
As a result, the switching member 16 moves from the forward rotation position A shown in FIG.
The rocking operation starts to the reverse rotation position B side shown in. in this case,
The rate of change of the detected value of the potentiometer 28 (the operating speed of the switching member 16) shown in FIG. 6 is the rate of change D1 corresponding to the operation current to the reverse rotation position B side (the above corresponds to the control means). .

When the switching member 16 approaches the reverse rotation position B side in FIG. 7 and the reverse rotation pulley 18 starts to be pressed against the outer surface of the first transmission belt 14, the tension of the first transmission belt 14 acts as resistance and the switching member 16 And, the motor 24 starts to be engaged. When the rate of change in the detected value of the potentiometer 28 (the operating speed of the switching member 16) decreases due to the resistance of the tension of the first transmission belt 14 and reaches the set value D2 (time point C3), the reverse rotation pulley 18 moves to the first position. It is determined that the switching member 16 has reached the reverse position B where the fan 9 is reversely driven by being pressed against the outer surface of the transmission belt 14 with sufficient force (see FIG. 7), and the motor 24 is moved to the reverse position B side. The operating current is cut off (time point C4). As a result, the motor 24 stops and the swinging operation of the switching member 16 toward the reverse rotation position B ends (the above is equivalent to the stopping means).

Next, when the set time T3 elapses with the switching member 16 in the reverse rotation position B (time C5), the operating current to the forward rotation position A side starts to be supplied to the motor 24, and the motor 24 and The switching member 16 is moved by the spring 27 as shown in FIG.
The swing operation starts from the reverse rotation position B shown in FIG. 6 to the forward rotation position A side shown in FIG. In this case, the rate of change of the detected value of the potentiometer 28 shown in FIG. 6 (the operating speed of the switching member 16)
Is the rate of change D1 corresponding to the above-described operation current to the normal rotation position A side (the above corresponds to the control means).

When the switching member 16 approaches the forward rotation position A side in FIG. 6 and the forward rotation pulley 17 starts to be pressed against the inner surface of the first transmission belt 14, the tension of the first transmission belt 14 acts as resistance to change the switching member. 16 and the motor 24 start to engage. When the rate of change of the detected value of the potentiometer 28 (the operating speed of the switching member 16) decreases due to the resistance of the tension of the first transmission belt 14 and reaches the set value D2 (time point C6), the forward rotation pulley 17 moves to the first position. It is determined that the switching member 16 has reached the normal rotation position A where the fan 9 is normally rotated by being pressed against the inner surface of the transmission belt 14 with sufficient force (see FIG. 6), and the normal rotation position A relative to the motor 24 is determined. The operating current to the side is cut off (time point C7). As a result, the motor 24 stops and the swinging operation of the switching member 16 toward the forward rotation position A is completed (the above is equivalent to the stopping means).

As shown in FIG. 5, the switching member 16 is swung from the forward rotation position A to the reverse rotation position B (from time C2 to time C).
4) and the swing operation from the reverse rotation position B to the forward rotation position A (time C5 to time C7), the swing position of the switching member 16 is continuously detected by the detection value of the potentiometer 28 in FIG. There is. As a result, during the swing operation of the switching member 16 from the forward rotation position A to the reverse rotation position B, the detection value of the potentiometer 28 has not yet reached the detection value corresponding to the reverse rotation position B in FIG. When the rate of change of the detected value of the potentiometer 28 falls below the set value D2, it can be determined that the switching member 16 has stopped during the swing operation from the forward rotation position A to the reverse rotation position B. Therefore, in such a case, an alarm buzzer (not shown) is activated to notify the operator of the abnormality.

On the contrary, during the swinging operation of the switching member 16 from the reverse rotation position B to the normal rotation position A, the potentiometer 2
When the rate of change of the detected value of the potentiometer 28 falls below the set value D2 even though the detected value of 8 has not reached the detected value corresponding to the normal position A of FIG. It can be determined that the switching member 16 has stopped during the swing operation to the rolling position A. Therefore, in such a case, an alarm buzzer (not shown) is activated to notify the operator of the abnormality.

[First Alternative Embodiment] The configuration shown in FIG. 10 may be used instead of the configuration shown in FIG. In the case of the configuration of FIG. 10, the potentiometer 28 shown in FIG. 6 is used only for detecting the swing position of the switching member 16, and separately from the potentiometer 28, the rotation speed of the motor 24 per unit time (the motor 24 A rotation speed sensor (corresponding to a speed sensor for the motor 24) (not shown) for detecting the operation speed of the motor is provided.

As a result, as shown in FIG. 10, the forward rotation position A of the switching member 16 is used as the first reference (time point C11),
The operating current is not supplied to the motor 24 until the set time T2 elapses, and the switching member 16 is held at the forward rotation position A. When the set time T2 elapses with the switching member 16 in the forward rotation position A (time point C12), the operating current to the reverse rotation position B side starts to be supplied to the motor 24, and the switching member 16 is shown in FIG. The swing operation starts from the forward rotation position A toward the reverse rotation position B shown in FIG. In this case, the detection value of the rotation speed sensor for the motor 24 is the detection value E1 corresponding to the operation current to the reverse rotation position B side (the above corresponds to the control means).

When the switching member 16 approaches the reverse rotation position B side in FIG. 7 and the reverse rotation pulley 18 starts to be pressed against the outer surface of the first transmission belt 14, the tension of the first transmission belt 14 acts as a resistance to change the switching member 16. And, the motor 24 starts to be engaged. When the detection value of the rotation speed sensor for the motor 24 decreases due to the resistance of the tension of the first transmission belt 14 and reaches the set value E2 (time C13), the reverse rotation pulley 18 is sufficiently attached to the outer surface of the first transmission belt 14. It is determined that the switching member 16 has reached the reverse rotation position B where the fan 9 is driven in reverse rotation (see FIG. 7), and the operation current to the reverse rotation position B side for the motor 24 is cut off (see FIG. 7). Time point C14). This allows
The motor 24 stops and the swinging operation of the switching member 16 to the reverse rotation position B side ends (the above is equivalent to the stopping means).

Next, when the set time T3 elapses with the switching member 16 in the reverse rotation position B (time C15), the operating current to the forward rotation position A side starts to be supplied to the motor 24, and the switching member is changed. 16 is the same as the position shown in FIG.
The swinging operation starts to the forward rotation position A side shown in. in this case,
The detection value of the rotation speed sensor for the motor 24 is the detection value E1 corresponding to the operation current to the forward rotation position A side (the above corresponds to the control means).

When the switching member 16 approaches the forward rotation position A side in FIG. 6 and the forward rotation pulley 17 starts to be pressed against the inner surface of the first transmission belt 14, the tension of the first transmission belt 14 acts as a resistance. 16 and the motor 24 start to engage. When the detected value of the rotation speed sensor for the motor 24 decreases due to the resistance of the tension of the first transmission belt 14 and reaches the set value E2 (time point C16), the forward rotation pulley 17 is sufficiently attached to the inner surface of the first transmission belt 14. It is determined that the switching member 16 has reached the forward rotation position A where the fan 9 is driven to rotate normally (see FIG. 6), and the operation current to the forward rotation position A side of the motor 24 is cut off. (Time point C17). This allows
The motor 24 stops and the swinging operation of the switching member 16 toward the forward rotation position A side ends (the above is equivalent to the stopping means).

As shown in FIG. 10, the swinging operation of the switching member 16 from the forward rotation position A to the reverse rotation position B (time point C12 to time point C14) and the swinging operation from the reverse rotation position B to the forward rotation position A ( From time C15 to time C17), the swing position of the switching member 16 is continuously detected by the detection value of the potentiometer 28 in FIG. Thereby, the switching member 16
During the swing operation from the forward rotation position A to the reverse rotation position B (or
During the swing operation from the reverse rotation position B to the forward rotation position A), the detected value of the potentiometer 28 is the reverse rotation position B in FIG.
Although the detected value corresponding to
When the operating current to the motor 24 suddenly increases as indicated by the two-dot chain line 0, it can be determined that the switching member 16 has stopped during the swing operation. Therefore, in such a case, an alarm buzzer (not shown) is activated to notify the operator of the abnormality.

As shown by the chain double-dashed line in FIG.
The detection value of the rotation speed sensor for the motor 24 decreases prior to the sudden increase of the operation current to the motor 4 or conversely, the detection value of the rotation speed sensor for the motor 24 is delayed after the sudden increase of the operation current to the motor 24. If the sudden increase in the operating current to the motor 24 does not match the decrease in the detection value of the rotation speed sensor for the motor 24, it can be determined that the rotation speed sensor for the motor 24 is abnormal. .

[Second Embodiment] The structure shown in FIG. 11 may be used instead of the structure shown in FIGS. Figure 1
In the case of the configuration of No. 1, the potentiometer 28 shown in FIG.
Is used only to detect the swing position of the switching member 16, and a rotation speed sensor (corresponding to a speed sensor for the fan 9) that detects the rotation speed of the fan 9 per unit time separately from the potentiometer 28 (see FIG. (Not shown).

As a result, as shown in FIG. 11, the forward rotation position A of the switching member 16 is used as the first reference (time point C21),
The operating current is not supplied to the motor 24 until the set time T2 elapses, and the switching member 16 is held at the forward rotation position A. In this case, the detection value of the rotation speed sensor for the fan 9 is the normal rotation detection value F1. When the set time T2 elapses with the switching member 16 in the forward rotation position A (time point C22), the operating current to the reverse rotation position B side starts to be supplied to the motor 24, and the switching member 16 is shown in FIG. The swing operation starts from the forward rotation position A toward the reverse rotation position B shown in FIG. In this case, the detection value of the rotation speed sensor for the fan 9 also decreases from the above-described normal rotation detection value F1 and reaches the stopped state (the above corresponds to the control means).

When the switching member 16 approaches the reverse rotation position B side in FIG. 7 and the reverse rotation pulley 18 begins to be pressed against the outer surface of the first transmission belt 14, the detection value of the rotation speed sensor for the fan 9 is also stopped. Then, it rises to the reverse side. Then, when the detection value of the rotation speed sensor for the fan 9 increases and reaches the reverse rotation set speed F4 (time point C23), the reverse rotation pulley 18 is pressed against the outer surface of the first transmission belt 14 with sufficient force. Then, it is determined that the switching member 16 has reached the reverse rotation position B where the fan 9 is driven in reverse rotation (see FIG. 7), and the motor 24
The operation current to the reverse rotation position B side with respect to is cut off (time point C24). As a result, the motor 24 is stopped and the swinging operation of the switching member 16 toward the reverse rotation position B is completed.
The detection value of the rotation speed sensor for the fan 9 is the detection value F of the reverse rotation.
3 (the above is equivalent to the stopping means).

Next, when the set time T3 elapses with the switching member 16 in the reverse rotation position B (time point C25), the operation current to the reverse rotation position B side starts to be supplied to the motor 24, and the switching member 16 starts. 6 from the reverse position B shown in FIG.
The swinging operation starts to the forward rotation position A side shown in. in this case,
The detection value of the rotation speed sensor for the fan 9 also decreases from the above-described reverse rotation detection value F3 to reach the stopped state (the above corresponds to the stop means).

When the switching member 16 approaches the normal rotation position A side in FIG. 6 and the normal rotation pulley 17 starts to be pressed against the inner surface of the first transmission belt 14, the detection value of the rotation speed sensor for the fan 9 also stops. It rises from the state to the forward rotation side. Then, when the detection value of the rotation speed sensor for the fan 9 increases and reaches the normal rotation set speed F2 (time point C26), the normal rotation pulley 17 presses the inner surface of the first transmission belt 14 with sufficient force. Then, it is determined that the switching member 16 has reached the normal rotation position A where the fan 9 is normally rotated (see FIG. 6), and the motor 24
The operating current to the reverse rotation position B side with respect to is cut off (time point C27). As a result, the motor 24 is stopped and the swinging operation of the switching member 16 toward the forward rotation position A side is completed.
The detection value of the rotation speed sensor for the fan 9 is the detection value F of the normal rotation.
It becomes 1 (the above corresponds to the stopping means).

[Third Embodiment] Switching member 16 shown in FIG.
Instead of the above cycle, it may be configured as shown in FIGS. 12 and 13. As shown in FIG. 13, during normal operation of the engine 5 (step S1) and during normal mowing work in which the threshing clutch (not shown) is operated to the engaged position (operation of the threshing device 2 in FIG. 1) (step S2). When the cutting process along one side of the field is completed and the machine reaches the edge of the ridge, and the cutting unit 3 shown in FIG. 1 is operated to be raised above the set height (step S3), as shown in FIG. Reversing mode cycle is 1
Only once (step S4). In other states, the switching member 16 is held at the forward rotation position A shown in FIGS. 3 and 6 (step S7).

In this reverse rotation mode cycle, as shown in FIG. 12, the switching member 16 is first held in the normal rotation position A for the set time T5, and then the switching member 16 is kept in the normal rotation position for the set time T6. Since the swing operation is performed from A to the reverse rotation position B, power is not transmitted to the fan 9 during this period. Then, the switching member 16 is held at the reverse rotation position B only for the set time T6, and then the switching member 16 is rocked from the reverse rotation position B to the normal rotation position A over the set time T6, and the cycle T1 is set to 1 End one reverse mode cycle. In this case,
2, the set time T6 in which the switching member 16 is rocked from the forward rotation position A to the reverse rotation position B (or vice versa) and the set time T6 in which the switching member 16 is held in the reverse rotation position B are substantially the same length. The setting time T5 in which the switching member 16 is held at the forward rotation position A is set longer than the setting time T6. Then, this reverse rotation mode cycle is performed based on the flow of operation of the switching member 16 shown in FIGS.

When the reverse rotation mode cycle of the cycle T4 is performed only once as described above, a timer (not shown) starts counting (step S5). As a result, even after the reversing mode cycle is performed once, the reversing mode cycle is performed until the set time elapses (step S6) even if the cutting unit 3 is lowered to the set height or less and then raised again. I try not to.

[Fourth Embodiment] In the embodiment shown in FIG. 6, instead of the wire 26 and the spring 27, one linking rod (not shown) is provided between the drive shaft of the motor 24 and the switching member 16. Alternatively, instead of the motor 24, an electric cylinder (not shown) may be used as an electric actuator and directly connected to the switching member 16. In the structure of FIGS. 3 and 4, the forward and reverse pulleys 17, 1
8 may be set to be reverse, and the forward rotation pulley 17 may be pressed against the outer surface of the first transmission belt 14, and the reverse rotation pulley 18 may be pressed against the inner surface of the first transmission belt 14. Good. In place of the structure shown in FIGS. 3 and 4, a transmission belt for transmitting normal rotation power and a forward rotation pulley 17 (tension pulley), and a transmission belt for transmitting reverse rotation power and a reverse rotation pulley 18 (tension pulley) are provided. A double tension type structure may be adopted.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

1] Overall side view of combine

FIG. 2 is a vertical sectional front view of the bonnet of the combine.

FIG. 3 is a front view showing a state of a switching member and first and second transmission belts in a normal rotation state.

FIG. 4 is a front view showing a state of a switching member and first and second transmission belts in a reverse rotation state.

FIG. 5 is a diagram showing a cycle of rocking operation of the switching member, an operating current to the motor, and an operating speed of the switching member (rate of change in the detected value of the potentiometer).

FIG. 6 is a front view showing a state of a switching member and first and second winding members in a normal rotation state.

FIG. 7 is a front view showing the states of the switching member and the first and second winding members in the reverse rotation state.

FIG. 8 is a vertical sectional side view in the vicinity of the switching member and the first and second winding members.

FIG. 9 is a cross-sectional view showing a support structure of a reverse rotation pulley in the switching member.

FIG. 10 is a diagram showing a cycle of rocking operation of a switching member, an operation current to a motor, and a detection value of a rotation speed sensor for a motor in a first another embodiment.

FIG. 11 is a diagram showing a cycle of rocking operation of a switching member, an operation current to a motor, and a detection value of a rotation speed sensor for a fan in a second alternative embodiment.

FIG. 12 is a diagram showing a reverse rotation mode cycle of a switching member in a third alternative embodiment.

FIG. 13 is a diagram showing the flow of control when operating the reverse rotation mode cycle of the switching member in the third alternative embodiment.

[Explanation of symbols]

 8 Radiator 9 Fan 14, 19 Belt transmission system 16 Switching member 17 Forward rotation pulley 18 Reverse rotation pulley 24 Electric actuator 28 Speed sensor A Forward rotation position B Reverse rotation position D2, E2 Set value F2 Forward rotation speed F4 Reverse rotation setting Number of rotations

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyoshi Hirata 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Inventor Shigeki Hayashi 64, Ishizukita-cho, Sakai City, Osaka Prefecture Inside the factory

Claims (3)

[Claims] 1. A fan (9) for a radiator (8) capable of rotating in the normal and reverse directions by a forward rotating pulley (17) so that outside air is sucked through the radiator (8).
A belt drive system capable of selectively transmitting a normal rotation power for driving the fan and a reverse rotation power for driving the fan (9) in the reverse direction by the reverse pulley (18) so that air flows in the opposite direction. 14) and (19), the forward rotation pulley (17) is operated to a transmission position and the reverse rotation pulley (18) is operated to a transmission interruption position so that forward rotation power is transmitted. The reverse position (A), the forward rotation pulley (17) is operated to the transmission blocking position, and the reverse rotation pulley (18) is operated to the transmission position so that the reverse rotation power is transmitted. ) And a movable switching member (16), and the switching member (16) can be operated to move to the forward rotation position (A) side and the reverse rotation position (B) side.
And the electric actuator (2
4) is provided with control means for supplying an operating current to the forward rotation position (A) side and the reverse rotation position (B) side of the switching member (16), and detects the operating speed of the switching member (16). A speed sensor (28) is provided, and when the detected value of the speed sensor (28) becomes equal to or less than a set value (2D), the operating current to the electric actuator (24) is cut off to stop the electric actuator (24). A forward / reverse switching structure of a fan for a radiator provided with a stopping means. 2. A fan (9) for a radiator (8) capable of rotating in the normal and reverse directions by a forward rotating pulley (17) so that outside air is sucked through the radiator (8).
A belt drive system capable of selectively transmitting a normal rotation power for driving the fan and a reverse rotation power for driving the fan (9) in the reverse direction by the reverse pulley (18) so that air flows in the opposite direction. 14) and (19), the forward rotation pulley (17) is operated to a transmission position and the reverse rotation pulley (18) is operated to a transmission interruption position so that forward rotation power is transmitted. The reverse position (A), the forward rotation pulley (17) is operated to the transmission blocking position, and the reverse rotation pulley (18) is operated to the transmission position so that the reverse rotation power is transmitted. ) And a movable switching member (16), and the switching member (16) can be operated to move to the forward rotation position (A) side and the reverse rotation position (B) side.
And the electric actuator (2
4) is provided with control means for supplying an operating current to the forward rotation position (A) side and the reverse rotation position (B) side of the switching member (16), and detects the operating speed of the electric actuator (24). A stop unit is provided which includes a speed sensor and shuts off the operating current to the electric actuator (24) to stop the electric actuator (24) when the detected value of the speed sensor becomes equal to or less than a set value (2E). Forward / reverse switching structure of fan for radiator. 3. A fan (9) for a radiator (8), which is capable of rotating in the normal and reverse directions, by a pulley (17) for normal rotation so that outside air is sucked in through the radiator (8).
A belt drive system capable of selectively transmitting a normal rotation power for driving the fan and a reverse rotation power for driving the fan (9) in the reverse direction by the reverse pulley (18) so that air flows in the opposite direction. 14) and (19), the forward rotation pulley (17) is operated to a transmission position and the reverse rotation pulley (18) is operated to a transmission interruption position so that forward rotation power is transmitted. The reverse position (A), the forward rotation pulley (17) is operated to the transmission blocking position, and the reverse rotation pulley (18) is operated to the transmission position so that the reverse rotation power is transmitted. ) And a movable switching member (16), and the switching member (16) can be operated to move to the forward rotation position (A) side and the reverse rotation position (B) side.
And the electric actuator (2
4) is provided with control means for supplying an operating current to the forward rotation position (A) side and the reverse rotation position (B) side of the switching member (16), and rotation for detecting the rotation speed of the fan (9). The fan (9) is equipped with a number sensor to set the normal rotation speed (F2).
And a forward / reverse switching structure for a fan for a radiator, which is provided with stop means for stopping the electric actuator (24) by cutting off the operating current to the electric actuator (24) when the set rotational speed (F4) for the reverse rotation is reached. .