JPH08189358A - Reverse driving mechanism for cooling air supply fan of working machine - Google Patents

Abstract

PURPOSE: To suppress generation of noises due to slipping by pressing a belt in a contact manner by means of an assistant tension supply mechanism so as to improve tensile force of the belt in shifting from a second transmission state to a first transmission state of the normal rotation clutch pulley, and releasing the press-contact to the belt in the reverse movement. CONSTITUTION: A first belt 14 is streatched over a driving pulley 12, a relay pulley 11 and an input pulley 13a of an alternator 13, while a second belt 19 is streatched over an input pulley 9a above a cooling wind supply fan supported to the relay pulley 11, a normal rotation clutch pulley 17, and a reverse rotation clutch pulley 18. The normal rotation clutch pulley 17 is arranged on a changeover member 16 integrally with the reverse rotation clutch pulley 18, in such a manner that a first transmission state of being in contact with a front surface of the first belt 14 is changed over with a second transmission state of being in contact with a back surface of the first belt 14. An assistant tension supply mechanism 30 is provided for pressing the transmission belt 14 in a contact manner and thereby improving tensile force of the transmission belt 14 in shifting from the second transmission state to the first transmission state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention hangs a first belt around a drive pulley and a relay pulley which are rotationally driven by an engine, and also transmits rotational power to a forward / reverse cooling air supply fan for a radiator. A belt transmission mechanism is configured by suspending a second belt across an input pulley, a forward rotation clutch pulley, and a reverse rotation clutch pulley that are interlockingly connected to the cooling air supply fan, and the forward rotation clutch pulley is the first belt. A first transmission state in which the belt belt surface of the first belt is in pressure contact with the first belt to rotate in conjunction with the second belt, and a second transmission state in which the reverse rotation clutch pulley is in pressure contact with the back surface of the first belt to rotate in conjunction with the first belt. Cooling of a working machine provided with position changing means for integrally changing the position of the forward rotation clutch pulley and the reverse rotation clutch pulley so that the clutch pulley for forward rotation and the clutch pulley for reverse rotation can be switched to the transmission state. On the reverse drive mechanism of the wind supply fan.

[0002]

2. Description of the Related Art Conventionally, as a reverse rotation drive mechanism for a cooling air supply fan of a work machine of this type, for example, one proposed in Japanese Patent Application No. 6-28689 filed by the applicant of the present invention, In order to remove dust on the radiator intake surface and dust adhering to the dust screen, the cooling air supply fan is temporarily driven in reverse to blow air in the opposite direction to suction and blow off the dust. It is known that the structure is changed. Then, in order to switch the cooling air supply fan between the normal rotation state and the reverse rotation state, the first transmission state and the second transmission state in which the forward rotation clutch pulley and the reverse rotation clutch pulley are pressed against the first belt. The positions of both clutch pulleys are integrally changed over.

[0003]

However, in the conventional structure described above, the reverse clutch pulley is the first.
When the reverse rotation driving state in which the belt is pressed against the belt is changed to the normal forward rotation driving state, that is, when the forward rotation clutch pulley is switched into the first transmission state in which the forward rotation clutch pulley is pressed against the first belt, the front surface of the first belt is directly rotated. Since the conversion clutch pulley was switched so as to press and contact at once, at the time of the switching, the tension was reduced by the reverse rotation clutch pulley of the first belt and the forward rotation clutch pulley, and the normal rotation clutch pulley was used. The velocity difference between the first belt and the forward rotation clutch pulley is large until the clutch pulley is in a state where a predetermined tension is applied to the first belt by a certain amount of pressure or more, so that the belly surface of the first belt is large. There is a high possibility that a temporary slip will occur between the normal rotation clutch pulley and the forward rotation clutch pulley, and the abnormal noise such as the belt squeaking due to the slip will occur, and The belt squealing it had become a strident. Therefore, in order to suppress the occurrence of annoying belt squeal phenomenon due to the slip, for example,
As shown in FIG. 16, the input pulley 9a provided on the drive shaft of the cooling air supply fan 9 and the relay pulley 11 that stretches the first belt 14 are adjacent to each other so as to be relatively rotatable around the coaxial core. It is conceivable that the speed difference between the two pulleys 9a and 11 may be reduced in advance before the forward rotation clutch pulley comes into contact with the abdominal surface of the first belt 14.
As the means, the input pulley 9a and the relay pulley 1 are used.
A method in which the viscous clutch 50 is interposed between the first and second clutches is conceivable. However, in this way, the viscous clutch 50
In the case where the viscous clutch 50 is interposed, the two pulleys 9a and 11 are in contact with each other in a half-clutch state so that the pulleys 9a and 11 can rotate at a similar speed. There has been a problem that the structure becomes expensive and the cost is high as a structure for simply eliminating the squeal of the belt. The present invention has been made in view of the above circumstances, and a cooling air supply fan for a working machine that can be configured at a relatively low cost so that a belt squeal phenomenon does not occur when switching from a reverse rotation drive state to a forward rotation drive state. The purpose is to provide a reverse rotation drive mechanism.

[0004]

According to a first aspect of the present invention, there is provided a reverse rotation drive mechanism for a cooling air supply fan for a working machine, wherein the forward rotation clutch pulley is set to the second transmission state from the second transmission state. 1 In the middle of moving to the transmission state, the first
An auxiliary tension applying mechanism that press-contacts the first belt so as to increase the tension of the belt and releases the press-contact to the first belt in the first transmission state and the second transmission state, in the position changing means. The characteristic configuration is that they are provided in association with each other. A reverse rotation drive mechanism for a cooling air supply fan for a working machine according to a second aspect of the present invention is the one having the above-described configuration, in which a tension mechanism for applying a predetermined tension to the first belt is provided and the forward rotation clutch pulley is provided. In the middle of moving from the second transmission state to the first transmission state, the tension mechanism is actuated to add tension to the first belt, and the tension mechanism is operated in the first transmission state and the second transmission state. 1 tension mechanism forcibly operating means for operating the tension mechanism so as to release the addition of tension to the belt,
It is characterized in that it is provided in association with the position changing means. The operation and effect of this characteristic configuration are as follows.

[0005]

That is, according to the structure of claim 1 of the present invention, the tension of the first belt is increased by the auxiliary tension applying mechanism during the movement of the forward rotation clutch pulley from the second transmission state to the first transmission state. The first belt is pressed into contact with the first belt so as to be raised, and the pressing contact of the auxiliary tension applying mechanism with respect to the first belt is released in the first transmission state and the second transmission state. Therefore, switching to the first transmission state is performed. Thus, when the forward rotation clutch pulley comes into pressure contact with the first belt, the first belt whose tension is kept relatively high does not easily escape, so that the forward rotation clutch pulley and the first belt are separated from each other. Slip is less likely to occur between the two, and thus belt squeal that may occur due to the slip is suppressed. In addition, claim 2 of the present invention
According to the structure, the tension mechanism forcibly operating means adds the tension to the first belt while the forward rotation clutch pulley moves from the second transmission state to the first transmission state, but operates the crutch mechanism. Then, in the first transmission state and the second transmission state, the tension mechanism is operated so as to release the addition of the tension to the first belt. Therefore, by switching to the first transmission state, the forward rotation clutch pulley moves the first belt. Since the first belt, which is maintained at a relatively high tension, does not easily escape when it comes into pressure contact with, the slip between the forward rotation clutch pulley and the first belt is less likely to occur. Therefore, the belt squeal that may occur due to the slip is suppressed.

[0006]

Therefore, the first and second aspects of the present invention are provided.
According to the above, there is a possibility that the forward rotation clutch pulley and the reverse rotation clutch pulley are loosened because the forward rotation clutch pulley and the reverse rotation clutch pulley are not pressed against each other when the forward rotation clutch pulley and the reverse rotation clutch pulley are shifted to the first transmission state. An expensive device such as a viscous clutch is used with a simple structure in which the tension of the first belt is not slackened by the auxiliary tension applying mechanism or the tension mechanism forcibly operating means for auxiliary tensioning the first belt. Since the belt squeaking phenomenon could be made less likely to occur at low cost without causing any discomfort to the worker due to the harsh belt squealing, a good working environment could be maintained at a low cost.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combine for harvesting and harvesting grains as an example of a working machine. This combine is equipped with a threshing device 2 in the rear part of the machine body supported by a pair of left and right crawler traveling devices 1, 1, a pre-mowing processing unit 3 in the front part of the machine body, and an operating section 4 on the right side of the rear part of the pre-mowing processing unit 3. Are arranged and configured. As shown in FIGS. 1 and 2, a bonnet 6 covering the engine 5 is provided with a control seat 7 for the driving section 4 in the upper part thereof, and a radiator 8 for the engine 5 and a cooling air supply fan 9 are provided in the bonnet 6. Are arranged.

Next, the drive structure of the cooling air supply fan 9 for the radiator 8 will be described. As shown in FIG. 2 to FIG. 5 and FIG. 9, the relay pulley 11 is fixed to the rotary shaft 10 supported on the side surface of the engine 5,
First, the output pulley 12 of the engine 5 as a drive pulley and the input pulley 13a of the alternator 13 are
I hang my belt 14. As shown in FIGS. 2 to 5, the support arm 15a is swingably supported by 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 biases the first belt 14 side is connected. As a result, the tension pulley 15 always presses the outer surface of the first belt 14.

A plate-shaped triangular switching member 16 is swingably supported on the rotating shaft 10, and a forward rotation clutch pulley 17 is pivotally supported by the switching member 16 such that two pulleys are coaxially and integrally rotatable. Similarly, there is provided a reverse rotation clutch pulley 18 in which two pulleys are coaxially and pivotally supported. The cooling air supply fan 9 is rotatably supported by a relay pulley 11 of the rotary shaft 10 via bearings, and an input pulley 9a is provided at the base of the cooling air supply fan 9. The input pulley 9a and the switching member 16 are provided. The second belt 19 is hung over the normal rotation and reverse rotation clutch pulleys 17 and 18. Then, as shown in FIG. 9, the forward rotation clutch pulley 17 is supported by a support shaft 17 a fixed to the switching member 16. On the other hand, as shown in FIG. 10, the support shaft 18a of the reverse rotation clutch pulley 18 has the elongated hole 1 of the switching member 16 formed by the bolt 21 and the bracket 22.
It is supported along position 6a so as to be adjustable in position, and is configured so that the distance between the forward and reverse clutch pulleys 17 and 18 can be finely adjusted.

Further, as shown in FIGS. 2 to 5, the outer surface of the first belt 14 between the output pulley 12 and the input pulley 13a of the alternator 13 is brought into contact with the first belt 14 and
The engine 5 swings the auxiliary tension pulley 30a, which constitutes the auxiliary tension applying mechanism 30 for applying a tension to the first belt 14 by pressing the inward direction, around the fixed swing fulcrum P4 of the engine 5. It is provided at the tip of the freely supported arm 30b. The second arm 30c swinging integrally with the arm 30b is provided so as to be interposed in the movement locus of the locking portion 16b projecting from the tip of the switching member 16. The locking portion 16b is pivotally attached to the switching member 16 so as to be swingable, the swinging of the reverse rotation clutch pulley 18 is restricted by the stopper 16c, and the forward rotation clutch pulley 17 is swingable to the predetermined range. It is free within.
Then, the arm 30b and the second arm 30c are connected to the spring 30.
It is elastically urged toward a predetermined stop position C which is separated from the first belt 14 by d. When the arm 30b is located at the predetermined stop position C, the second arm 30
The leading end portion of d is positioned so as to interfere with the movement trajectory of the locking portion 16b. Here, the auxiliary tension pulley 30a, the arm 30b, the second arm 30c, the spring 3
0d, the locking portion 16b, and the stopper 16c constitute an auxiliary tension applying mechanism 30.

With the above structure, the output pulley 12 and the first
The belt 14 is constantly rotating in the direction of the arrow shown in FIGS. When the switching member 16 is rocked to the forward rotation position A shown in FIG. 5, the forward rotation clutch pulley 17 is moved to the first position.
The inner surface of the belt 14 is pressed from the right side of the drawing, and the power of the first belt 14 is transmitted to the input pulley 9a as the normal rotation power via the forward rotation clutch pulley 17 and the second belt 19 to supply the cooling air supply fan 9 and the input. The pulley 9a is driven to rotate in the clockwise direction on the paper surface of FIG. In the state in which the cooling air supply fan 9 is normally driven in this way, the outside air serves as cooling air due to the suction action of the cooling air supply fan 9 as shown by the solid line arrow in FIG. It flows through 8 to the engine 5 side, and this state is a normal state.

Conversely, when the switching member 16 is rocked to the reverse rotation position B shown in FIG. 3, the reverse rotation clutch pulley 18 is moved to the first position.
The power of the first belt 14 is pressed against the outer surface of the belt 14 from the left side of the drawing, and the power of the first belt 14 is transmitted through the reverse rotation clutch pulley 18 and the second belt 19 as the second transmission belt.
The power for reverse rotation is transmitted to a, and the cooling air supply fan 9 and the input pulley 9a are reversely driven counterclockwise in FIG. When the cooling air supply fan 9 is driven in the reverse direction as described above, the air flows in the opposite direction to the above by the blowing action of the cooling air supply fan 9 as shown by the double-dashed line arrow in FIG. Dust and the like attached to the surface and the dustproof net 20 (especially on the lower side) are blown off.

Next, the switching member 1 for the cooling air supply fan 9
The structure of the rocking operation 6 will be described. As shown in FIG. 7, the 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 driven to rotate. An electric motor 24 is provided, and a semi-disc-shaped second winding member 25 is also fixed to the switching member 16. Here, the electric motor 24 is controlled by a control unit (not shown) so that the electric motor 24 is periodically operated as described later. And
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. 23a and the switching member 16 and the spring 2
7 is connected. Here, the first winding member 23,
The electric motor 24, the control means, the second winding member 25, the wire 26, and the spring 27 constitute a position changing means.

The state shown in FIG. 7 is the first winding member 23.
Is positioned at an angle corresponding to the forward rotation position A of the switching member 16, and the pulling action of the spring 27 causes the switching member 16 to swing to the forward rotation position so that the cooling air supply fan 9 rotates normally. It is in a driven state (see FIG. 5). In this state, the wire 26 slightly sags, and the biasing force of the spring 27 and the tension of the first belt 14 are balanced. in this case,
The spring 27 and the pin 23a cross the axis P1 of the first winding member 23 to the right side of the drawing, and the first force is applied by the spring 27.
The winding member 23 is about to be rotated clockwise in the drawing, but since the stopper 29 that stops the first winding member 23 at the angle shown in FIG. 7 is provided, the spring 27
By the action of the urging force and the stopper 29, the first winding member 23 is held at the angle shown in FIG. Further, the second arm 30c of the auxiliary tension applying mechanism 30 remains positioned in the movement locus of the locking portion 16b.

Next, when the electric motor 24 drives the first winding member 23 to rotate counterclockwise about 180 degrees in the drawing, the wire 26 is pulled by the first winding member 23 while being wound, and is switched. The member 16 and the second winding member 25 are also swung counterclockwise on the paper surface, the switching member 16 is swung to the reverse position B as shown in FIG. 8, and the cooling air supply fan 9 is reversely driven ( (See FIG. 3). As shown in FIGS. 5 to 3, 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. However, 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 (about the length of the diameter of the first winding member 23). The spring 27 does not have a great resistance to the swinging operation from the forward rotation position A to the reverse rotation position B. Then, the locking portion 16b is in the middle of its movement and the auxiliary tension applying mechanism 30
Of the second arm 30c, but the engaging portion 16b
It does not swing and escape to press the second arm 30c.

On the contrary, as shown in FIG. 8, the first winding member 2
When the first winding member 23 is rotationally driven by the electric motor 24 in the clockwise direction of the drawing by about 180 degrees 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. 5 is drawn out from the take-up member 23, the spring 27 is pulled by the movement of the pin 23a, and the switching member 16 and the second take-up member 25 are also swung counterclockwise on the paper surface by the urging force of the spring 27. As shown, the switching member 16 is swung to the forward rotation position A. Then, at the time of the swing, as shown in FIG.
The second arm 30 with b being restricted by the stopper 16c
The second arm 30c and then the arm 30b are swung by coming into contact with the tip end of c to apply tension to the first belt 14 by the tension pulley 30a. Locking portion 16b,
The mutual unlocking position set by the size and installation position of the second arm 30c and the like is the position where the forward rotation clutch pulley 17 is pressed against the first belt 14 to some extent, and therefore, for forward rotation. The clutch pulley 17 contacts and presses the first belt 14, which has some tension. Even if the locking portion 16b and the second arm 30c are unlocked, the forward rotation clutch pulley 17 presses the first belt 14, so that slippage between them does not easily occur.

Next, a cycle for swinging the switching member 16 to the reverse position B shown in FIGS. 3 and 8 will be described. In this cycle, as shown in FIG. 6, 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 oscillated from the forward rotation position A to the reverse rotation position B over the set time T4, and during this time, the power is not transmitted to the cooling air supply fan 9. Then, the switching member 16 is held at the reverse rotation position B only for the set time T3, and then the switching member 16 is swung from the reverse rotation position B to the forward rotation position A over the set time T5, and the cycle T1 is set to 1 End cycle. The setting of this cycle is sequentially performed by the timer operation in the above-mentioned control means.

In the above cycle, the power to the cooling air supply fan 9 is once cut off from the state in which the cooling air supply fan 9 is normally driven (see the neutral position in FIG. 6). Relatively large dust and the like adhering to the surface of the radiator 8 (the surface on the left side of the paper surface of FIG. 2) is dropped below the space between the radiator 8 and the dustproof net 20 by the vibration of the machine body. Next, by driving the cooling air supply fan 9 in the reverse direction, dust and the like adhering to the surface of the radiator 8 is blown off. As shown in FIG. 6, a set time T4 in which the switching member 16 is rocked from the forward rotation position A to the reverse rotation position B (or vice versa), and a setting time T3 in which the switching member 16 is held in the reverse rotation position B. Are set to 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 set to be sufficiently longer than the set times T3 and T4 described above. Further, the set time T5 is set longer than the set time T4 as described later.

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. 7, a rotary potentiometer 28 is fixed to the lateral side surface of the engine 5, a rubber roller 8a is fixed to a rotary detection shaft of the potentiometer 28, and the roller 28a is wound in a second winding direction. Collecting member 25
It is applied to the outer peripheral surface of. As a result, the swing position of the switching member 16 is continuously detected by the detection value of the potentiometer 28.
The operating speed of the switching member 16 is continuously detected by differentiating the detected value of.

As shown in FIG. 6, with the forward rotation position A of the switching member 16 as the initial reference (time point C1), the operating current is not supplied to the electric motor 24 until the set time T2 elapses, and the switching member is changed. 16 is held at the normal rotation position A. When the set time T2 elapses with the switching member 16 in the forward rotation position A (time point C2), the operating current to the reverse rotation position B side starts to be supplied to the electric motor 24, and the electric motor 24 and the wire 26 cause The switching member 16 starts to be rocked from the normal rotation position A shown in FIG. 5 to the reverse rotation position shown in FIG. 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.
The rate of change D1 corresponds to the operating current to the side.

When the switching member 16 approaches the reverse rotation position B side in FIG. 3 and the reverse rotation clutch pulley 18 starts to be pressed against the outer surface of the first belt 14, that is, the rear surface, the tension of the first belt 14 switches as resistance. The member 16 and the electric motor 24 start to be hooked. When the absolute value of the change rate of the detection value of the potentiometer 28 (moving speed of the switching member 16) decreases due to the resistance of the tension of the first belt 14 and reaches the set value D2 (time point C3), the reverse rotation clutch pulley 18 moves to the first position. The switching member 1 is moved to the reverse position B as the second state in which the cooling air supply fan 9 is reversely driven by being pressed against the outer surface of the belt 1 with a sufficient force.
6 is determined (see FIG. 6), the electric motor 24
The operating current to the reverse rotation position B side with respect to is cut off (time point C4). As a result, the electric motor 24 stops and the swinging operation of the switching member 16 toward the reverse rotation position B is completed.

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 electric motor 24, and the electric motor is started. Switching member 1 by means of 24 and spring 27
6 is from the reverse rotation position B shown in the figure to the normal rotation position A shown in FIG.
It begins to be rocked to the side. In this case, the rate of change of the detected value of the potentiometer 8 (moving speed of the switching member 16) shown in FIG. 6 is the rate of change D1 corresponding to the operation current to the forward rotation position A side described above. When the switching member 16 approaches the forward rotation position A side in FIG. 5 and the forward rotation clutch pulley 17 starts to be pressed against the inner surface of the first belt 14, that is, the abdominal surface, the tension of the first belt 14 acts as a resistance. And the electric motor 24 starts to be applied. When the absolute value of the change rate of the detection value of the potentiometer 28 (moving speed of the switching member 16) decreases due to the resistance of the tension of the first belt 14 and reaches the set value D2 (time point C6), the forward rotation clutch pulley 17 is activated. First
The normal rotation position A as the first state in which the cooling air supply fan 9 is normally rotated by being pressed against the inner surface of the belt 14 with sufficient force.
When it is determined that the switching member 16 has reached (see FIG. 6), the operating current to the forward rotation position A side of the electric motor 24 is cut off (time point C7). As a result, the electric motor 24 is stopped and the swinging operation of the switching member 16 toward the forward rotation position A is completed.

As shown in FIG. 6, the swinging operation of the switching member 16 from the forward rotation position A to the reverse rotation position B (from the time point C2 to the time point 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 swing operation of the switching member 16 from the reverse rotation position B to the normal rotation position A, the potentiometer 2
If the switching member 16 is finally stopped even though the detection value of 8 has not reached the detection value corresponding to the normal rotation position A in FIG. 5, the reverse rotation position B is changed to the normal rotation position A. It can be determined that the switching member 16 has stopped during the swing operation of. Therefore, in such a case, an alarm buzzer (not shown) is activated to notify the operator.

Another Embodiment Next, an embodiment of the present invention according to claim 2 will be described. The description of the same structure as that of the above-described embodiment will be omitted and the same reference numerals will be given to the description. As shown in FIG. 11, the first belt 14
The other end of the spring 15b of the support arm a of the tension pulley 15 for pre-tensioning the
It is connected to one end portion of a first link arm 31 which is swingably supported around 5. The pin 31a provided at the other end of the first link arm 31 is engaged with the long hole 32a formed at one end of the second link arm 32 that the engine 5 swingably supports around the alligator shaft P6. are doing. The other end of the second link arm 32 is formed on a cam follower 32b, and the cam follower 32b is provided on the second winding member 25.
Cam 33 formed to bulge outward from the outer peripheral edge of the
To be guided by. Here, the tension pulley 15, the support arm a, the spring 15b, the first link arm 31, the second link arm 32, and the cam 33 constitute a tension mechanism forced actuation means 34.

In the above-mentioned structure, the contact position of the cam 33 with the cam follower 32b is the forward rotation clutch pulley 17a.
Between the forward rotation position A where the first belt 14 is pressed against the first belt 14 and the reverse rotation position B where the reverse rotation clutch pulley 18 is pressed against the first belt 14 in the radial direction from the axis P1. Although it is the same as the position of the outer peripheral edge portion of 23, in the range where both the forward rotation and reverse rotation clutch pulleys 17 and 18 are not in contact with the first belt 14, substantially the second winding is performed in the radial direction from the shaft center. It is set so that the outer side of the removing member 25 is located at the outer peripheral edge portion. Therefore, according to the above configuration, the connection position of the spring 15b with the first link arm 32 is located outward in the forward rotation position A and the reverse rotation position B due to the contact position of the cam follower 32b with respect to the cam 33. The first belt 1 of the tension pulley 15
The pressing position with respect to 4 is a relatively outward normal position. On the other hand, in the range in which the forward and reverse clutch pulleys 17 and 18 move between the forward rotation position A and the reverse rotation position B, the connection position of the spring 15b with the first link arm 32 contacts the cam 33 against the cam follower 32b. Due to the positional relationship, since the tension pulley 15 is located inward, the pressing position of the tension pulley 15 against the first belt 14 is relatively inward, and the forward and reverse clutch pulleys 17,
The slack of the first belt 14 when 18 is not pressing the first belt 14 is absorbed by pressing the first belt 14 so that it is located closer to the inner side of the tension pulley 15 and applying tension. There is.

Next, one of the other embodiments according to claim 1 of the present invention will be described. The description of the same structure as that of the above-described embodiment will be omitted and the same reference numerals will be given to the description. As shown in FIG. 12, the shaft member 36 is slidably mounted in the longitudinal direction of the shaft guide cylinder 35 which is fixedly provided to the engine 5. More specifically, a through hole for inserting and guiding the shaft member 36 is formed in the bottom portion of the shaft guide cylinder 35, and the shaft member 3 is provided.
The second winding member 25 of 6 has the second winding member 25 at one end thereof.
A contact action portion 36a is provided which is in contact with a cam 33 formed in a state of bulging outward from the outer peripheral edge portion of the winding member 25 to be pushed and guided. A compression coil spring 37 is mounted over the flange portion near the abutment action portion 36a and the bottom portion of the shaft guide cylinder 35, whereby the shaft member 36 abuts the cam 33 but is pressed and biased by the alligator. There is. On the other hand, an auxiliary tension pulley 38 is provided at the other end of the shaft member 36 opposite to the first winding member 23. Here, the cam 33, the shaft guide cylinder 35, the shaft member 36, the compression coil spring 37, and the auxiliary tension pulley 38 constitute the auxiliary tension applying mechanism 30.

In the above structure, the contact position of the cam 33 with the contact action portion 36a is the normal rotation position A where the normal rotation clutch pulley 17 contacts and presses the first belt 14, and the reverse rotation clutch pulley 18 is the first position. The reverse rotation position B in which the belt 14 is pressed against the belt 14 is substantially the same as the position of the outer peripheral edge portion of the first winding member 23 in the radial direction from the axis P1, but the forward rotation and reverse rotation clutch pulleys 17 and 18 are used. Is set so that the outer side of the second winding member 25 is located substantially outside the position of the outer peripheral edge portion of the second winding member 25 in the radial direction from the shaft center in the range where both of them are not in contact with the first belt 14. In addition, the auxiliary tension pulley 3
8 is a displacement regulation by the cam 33 of the shaft member 36,
The forward rotation position A where the forward rotation clutch pulley 17 contacts and presses the first belt 14 and the reverse rotation position B where the reverse rotation clutch pulley 18 contacts and presses the first belt 14 are contact positions with the first belt 14. The clutch pulleys 17 and 18 for the forward rotation and the reverse rotation are both located at the inner position retracted from
As long as the belt 14 is not in contact with the belt 14, the first belt 14
Is located at a position where it is urged outwardly, and the forward and reverse clutch pulleys 17 and 18 are attached to the first belt 1.
The slack of the first belt 14 when the first belt 14 is not pressed is absorbed by the auxiliary tension pulley 38 being positioned outward so that the first belt 14 is pressed and tension is applied. are doing.

Next, one of other embodiments according to claim 1 of the present invention will be described. The description of the same structure as that of the above-described embodiment will be omitted and the same reference numerals will be given to the description. As shown in FIG. 13, the forward rotation position A of the switching member 16, the forward rotation and the reverse rotation clutch pulleys 17, 18 is shown.
The auxiliary arm 39 is provided integrally with the second winding member 25 or the switching member 16 so as to be rotatable around the axis P1 which is the center of swinging between the auxiliary arm 39 and the reverse position B, and assists at the tip of this auxiliary arm 39. A tension pulley 40 is provided. The auxiliary tension pulley 40 is the relay pulley 11
The switching member 16 swings from the reverse rotation position B to the forward rotation position A as shown in FIG. When the forward rotation clutch pulley 17 contacts the abdominal surface of the first belt 14, the auxiliary tension pulley 40
Is set so as to be in contact with the back surface of the first belt 14. The forward rotation clutch pulley 17 is the first
When the first belt 14 is brought into contact with the belt 14, the tension of the first belt 14 should be increased to some extent.
Is maintained at. As described above, when the tension of the first belt 14 is relatively high, the forward rotation clutch pulley 17 contacts the first belt 14, so that slipping and belt noise are suppressed. Further, when the forward rotation clutch pulley 17 is in the forward rotation position A, the auxiliary tension pulley 40 is located outside the forward rotation clutch pulley 17, so that the auxiliary tension pulley 40 contacts the first belt 14. It is supposed not to hit. Here, the auxiliary arm 39 and the auxiliary tension pulley 40 form an auxiliary tension applying mechanism 30.

Next, one of the other embodiments according to claim 1 of the present invention will be described. The description of the same structure as that of the above-described embodiment will be omitted and the same reference numerals will be given to the description. As shown in FIG. 14, the forward rotation position A of the switching member 16, the forward rotation and reverse rotation clutch pulleys 17, 18 is shown.
And the reverse rotation position B, the auxiliary arm 41 is rotatable about an axis P1 which is the center of swing, and the switching member 16 is extended from the forward rotation clutch pulley 17 to a wire farther from the axis P1. The auxiliary tension pulley 42 is provided at the tip of the auxiliary arm 41. The auxiliary tension pulley 42 is the relay pulley 11
The switching member 16 swings from the reverse rotation position B to the normal rotation position A as shown in FIG. When the forward rotation clutch pulley 17 contacts the abdominal surface of the first belt 14, the auxiliary tension pulley 42
Is set so as to be in contact with the back surface of the first belt 14. The forward rotation clutch pulley 17 is the first
When the first belt 14 is brought into contact with the belt 14, the tension of the first belt 14 is increased to some extent and the auxiliary tension pulley 42
Is maintained at. As described above, when the tension of the first belt 14 is relatively high, the forward rotation clutch pulley 17 contacts the first belt 14, so that slipping and belt noise are suppressed. Further, when the forward rotation clutch pulley 17 is in the forward rotation position A, the auxiliary tension pulley 42 is located outside the forward rotation clutch pulley 17, so that the auxiliary tension pulley 42 contacts the first belt 14. It's not hitting. Here, the auxiliary arm 41 and the auxiliary tension pulley 42 form the auxiliary tension applying mechanism 30.

Next, another embodiment according to claim 2 of the present invention will be described. The description of the same structure as that of the above-described embodiment will be omitted and the same reference numerals will be given to the description. As shown in FIG. 15, the shaft member 44 is slidably mounted in the longitudinal direction of the shaft guide cylinder 43 which is fixedly provided to the engine 5. To elaborate,
A through hole for inserting and guiding the shaft member 44 is formed in the bottom portion of the shaft guiding cylinder 43, and the second winding member 25 of the shaft member 44 is provided at one end thereof with the first winding member 25. A contacting action part 44a is provided which is pressed against and guided by a cam 45 which is formed so as to bulge outward from the outer peripheral edge of the winding member 23. A compression coil spring 46 is mounted over the flange portion near the abutment action portion 44a and the bottom portion of the shaft guiding cylinder 43.
The shaft member 44 is in contact with the cam 45, but is pressed and biased by the burr. On the other hand, the spring 1 for applying an elastic biasing force to press the tension pulley 15 against the first belt 14 is provided at the other end of the shaft member 43 opposite to the second winding member 25.
The other end of the wire 47, which is connected to the other end of the wire 5b, is connected to the other end. The wire 47 is guided by a guide roller 48 provided on the crocodile of the engine 5. Here, the cam 45, the shaft guiding cylinder 43, the shaft member 44,
The compression coil spring 46, the wire 47, and the guide roller 48 constitute the tension mechanism forcibly operating means 34.

In the above structure, the contact position of the cam 45 with the contact action portion 44a is the normal rotation position A where the normal rotation clutch pulley 17 contacts and presses the first belt 14, and the reverse rotation clutch pulley 18 is the first position. The reverse rotation position B in which the belt 14 is pressed against the belt 14 is substantially the same as the position of the outer peripheral edge portion of the second winding member 25 in the radial direction from the shaft core, but the forward rotation and reverse rotation clutch pulleys 17 and 18 are First belt 14 together
In a range not in contact with, the outer circumference of the second winding member 25 is set to be substantially outside in the radial direction from the shaft center. The positions of the other end of the shaft member 44 are the normal rotation position A where the forward rotation clutch pulley 17 contacts and presses the first belt 14 and the reverse rotation clutch pulley 18 by the displacement regulation of the shaft member 44 by the cam 45. Is located at a position where the urging force of the compression coil spring 46 against the tension pulley 15 is weakened, and the forward rotation and reverse rotation clutch pulleys 17 and 18 are both in the first position. The compression coil spring 46 is located in a position where the biasing force of the compression coil spring 46 against the tension pulley 15 is weakened in a range where it is not in contact with the belt 14, and the forward and reverse clutch pulleys 17 and 18 press the first belt 14. When the tension pulley 15 is positioned on the inner side, the slack of the first belt 14 when not being applied can be applied to the first belt 14 by pressing force. The first was pressurized 1
The slack of the belt 14 is absorbed.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of drawings]

FIG. 1 is an overall side view showing a combine.

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

FIG. 3 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. in the reverse rotation state of the invention according to claim 1;

FIG. 4 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. during the switching to the normal rotation state of the invention according to claim 1;

FIG. 5 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. in the normal rotation state of the invention according to claim 1;

FIG. 6 is a graph showing how the swing position of the switching member, the operating current to the motor, and the rate of change in the detected value of the potentiometer change over time.

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

FIG. 8 is a side view showing the states of the switching member and the first and second winding members in the reverse rotation state.

FIG. 9 is a vertical sectional front view of the vicinity of the switching member and the first and second winding members.

FIG. 10 is a cross-sectional view showing a support structure of a reverse rotation pulley in the switching member.

FIG. 11 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. during the switching to the normal rotation state of the invention according to claim 2;

FIG. 12 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. during the switching to the normal rotation state of another embodiment of the invention according to claim 1;

FIG. 13 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. during the switching to the normal rotation state of another embodiment of the invention according to claim 1;

FIG. 14 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. during the switching to the normal rotation state of another embodiment of the invention according to claim 1;

FIG. 15 is a side view showing the states of the switching member, the transmission belt, the second transmission belt, etc. during the switching to the normal rotation state of another embodiment of the invention according to claim 2;

FIG. 16 is a vertical sectional front view of a switching member and first and second winding members and their vicinity as a comparative example.

[Explanation of symbols]

 5 engine 8 radiator 9 cooling air supply fan 9a input pulley 11 relay pulley 12 drive pulley 14 first belt 15 tension mechanism 17 forward rotation clutch pulley 18 reverse rotation clutch pulley 19 second belt 30 auxiliary tension applying means 34 tension mechanism forcing means

Claims (2)

[Claims] 1. A first belt (1) is attached to a drive pulley (12) and a relay pulley (11) which are rotationally driven by an engine (5).
4) The input pulley which hangs up the belt wind-up mechanism for transmitting the rotational power to the cooling air supply fan (9) for the radiator (8), which can be rotated forward and backward, in conjunction with the cooling air supply fan (9). (9a), the forward rotation clutch pulley (17), and the reverse rotation clutch pulley (18), the second belt (19) is suspended, and the forward rotation clutch pulley (17) is formed by the first belt (19). 1
4) a first transmission state in which the belt abdominal surface of the first belt (14) is pressed and brought into contact with the first belt (14), and the reverse clutch pulley (18) rotates in conjunction with the first belt (14). Position change means for integrally changing the position of the forward rotation clutch pulley (17) and the reverse rotation clutch pulley (18) is provided such that the first transmission belt (14) can be switched to the second transmission state in which the first belt (14) is pressed against the back surface of the belt. A reverse rotation drive mechanism for a cooling air supply fan of a working machine, wherein the forward rotation clutch pulley (17) moves from the second transmission state to the first transmission state while the first belt (1)
4) An auxiliary tension applying mechanism that press-contacts the first belt (14) so as to increase the tension, and releases the press-contact to the first belt (14) in the first transmission state and the second transmission state. (30) is a reverse rotation drive mechanism for the cooling air supply fan of the working machine, which is provided in association with the position changing means. 2. A first belt (1) is attached to a drive pulley (12) and a relay pulley (11) which are rotationally driven by an engine (5).
4) The input pulley which hangs up the belt wind-up mechanism for transmitting the rotational power to the cooling air supply fan (9) for the radiator (8), which can be rotated forward and backward, in conjunction with the cooling air supply fan (9). (9a), the forward rotation clutch pulley (17), and the reverse rotation clutch pulley (18), the second belt (19) is suspended, and the forward rotation clutch pulley (17) is formed by the first belt (19). 1
4) a first transmission state in which the belt abdominal surface of the first belt (14) is pressed and brought into contact with the first belt (14), and the reverse clutch pulley (18) rotates in conjunction with the first belt (14). Position change means for integrally changing the position of the forward rotation clutch pulley (17) and the reverse rotation clutch pulley (18) is provided such that the first transmission belt (14) can be switched to the second transmission state in which the first belt (14) is pressed against the back surface of the belt. A reverse rotation drive mechanism for a cooling air supply fan of a working machine, wherein a tension mechanism (15) for applying a predetermined tension to the first belt (14) is provided, and the forward rotation clutch pulley (17) is provided with the second clutch pulley (17). In the middle of moving from the power transmission state to the first power transmission state, the tension mechanism (15) is operated to add tension to the first belt (14) to operate the first power transmission state and the second power transmission state. Work in which a tension mechanism forced actuation means (34) for actuating the tension mechanism (15) so as to release the addition of tension to the first belt (14) is provided in association with the position changing means. Reverse rotation drive mechanism for the cooling air supply fan of the machine.