JPH0552243A - Engine cooling device - Google Patents

Abstract

PURPOSE:To reduce the shock in selection by installing a normal revolution pulley and a reverse revolution pulley so as to be selected in the opposite transmission state and maintaining the neutral state where any pulley is not press-attached with a transmission belt in the normal/reverse revolution selection operation for a prescribed time. CONSTITUTION:The first transmission belt 12 which is always revolution-driven is laid on a normal revolution pulley 13, and the transmission state can be selected in press-contact and separation from the inner peripheral surface of the transmission belt 13. A pulley 14 for reverse revolution can be similarly selected between press contact and separation an the outer peripheral surface of the first transmission belt 12. Further, a driven pulley 15 for a cooling fan 16 is provided, and the second transmission belt 16 is winding-laid between the pulleys 13-15. Further, a normal/reverse revolution selecting mechanism A is constituted of the normal revolution pulley 13 and the reverse revolution pulley 14, and a neutral state maintaining means B which maintains the state where any pulley 13, 14 is not press-attached with the first transmission belt 12 for a prescribed time in the normal and reverse revolution selection is provided. Accordingly, the smooth operation in the normal/reverse revolution selection is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cooling device provided in, for example, a combine and other agricultural vehicles.
More specifically, the present invention relates to an engine cooling device configured to transmit power from an output shaft of an engine to a radiator cooling fan via a forward / reverse switching mechanism.

[0002]

2. Description of the Related Art Conventionally, in the above engine cooling device, as disclosed in, for example, Japanese Patent Laid-Open No. 2-217664, a gear meshing type positive shaft is arranged between a crank shaft of an engine and a drive shaft of a radiator cooling fan. A structure in which a reverse rotation switching mechanism is interposed has been proposed.

[0003]

However, according to the above-mentioned conventional structure, since the structure in which the gear meshing type switching mechanism is interposed, there is a drawback that the drive noise becomes large, and the drive shaft continuously rotating at a high speed. On the other hand, since the structure is such that the normal rotation state is immediately switched to the reverse rotation state, there is also a drawback that the driving structure is complicated for smooth operation. An object of the present invention is to solve the above-mentioned problems, to provide a smooth forward / reverse switching operation, a simple structure, and excellent durability.

[0004]

According to the characteristic construction of the present invention, in the structure described at the beginning, a first transmission belt which is constantly rotated by the output shaft is stretched, and an inner peripheral surface of the first transmission belt is stretched. A forward rotation pulley that can be switched between a state of being pressed and driven to rotate for driving and a state of being separated from being separated from transmission, and a state of being separated from being rotated by being pressed against the outer peripheral surface of the first transmission belt and being separated from being separated from transmission. A reversing pulley that can be switched to
The second transmission belt is wound around the driven pulley of the cooling fan and wound around the driven pulley, and the forward rotation pulley and the reverse rotation pulley are provided so that they can be switched to a transmission state in a contradictory manner. A switching mechanism is configured, and when the forward / reverse rotation switching operation is performed, when the normal rotation state or the reverse rotation state is switched to another switching state, in the middle thereof,
Each of the pulleys is provided with a neutral state maintaining means for maintaining the neutral state in which the pulleys are not in pressure contact with the first transmission belt for a predetermined time.

[0005]

When the normal rotation pulley is in pressure contact with the first transmission belt and is in a transmission state, the cooling fan sucks the outside air to perform a normal radiator cooling operation, and the radiator suction portion is accompanied by such cooling operation. Even if dust is attached, if the forward rotation pulley is separated and the reverse rotation pulley is pressed into a transmission state, the cooling fan reverses and a wind is generated that goes to the outside via the radiator. The dust adhering to the suction part of the radiator is blown away to the outside. Moreover,
When switching between forward and reverse, the neutral state is always maintained for a predetermined time. Therefore, when the driven side, that is, the cooling fan and the second transmission belt are rotated at high speed by inertia at the time of switching, the pulley becomes the first transmission belt. Since there is no pressure contact, the belt and pulley are less likely to be pressure-contacted in the reverse rotation state, resulting in heat generation and wear due to slip.

[0006]

Therefore, the normal cooling operation can be performed by rotating the cooling fan in the normal direction, and the dust adhering to the radiator suction portion can be blown off by periodically rotating the cooling fan in the reverse direction. Although it is possible to prevent early clogging due to the accumulation of dust and continue smooth engine cooling operation for a long period of time, the engine output shaft continues to rotate at high speed during engine operation. Since the structure is such that the forward / reverse rotation of the fan is switched by pressure contact / separation, the impact accompanying the switching is small, and the drive noise during transmission is also small. Moreover, since it is composed of the transmission belt and the pulley, it is not necessary to perform highly accurate processing such as the gear type switching mechanism, and the number of parts is small, and the structure can be simplified. Furthermore, as a result of adopting the belt transmission structure, it has become possible to provide a product having excellent durability by suppressing the generation of heat and wear due to friction that is likely to occur.

[0007]

Embodiments will be described below with reference to the drawings. Figure 4
Shows the combine drive section. The engine 2 is mounted and supported on the machine body frame 1, the driving seat 4 is placed and supported on the upper surface of the driving part cover 3 that covers the engine 2, and the engine is provided on the lateral side and the rear side of the driving part cover 3. An outside air suction portion for cooling is formed. A radiator 5 for cooling is provided at a location on the outer side of the body of the engine 2, and a fan 6 driven by the engine 2 sucks outside air from the outside air intake portion to cool the radiator 5. That is, the radiator 5 is arranged at a location on the outer side of the body of the engine 1, and the fan 6 is arranged between the engine 2 and the radiator 5. An intake duct 7 that forms an outside air intake path that connects to the intake portion of the radiator 5 is provided so as to extend across the lateral side portion and the rear portion side of the driving portion 8. The intake duct 7 has an outside air intake portion 9 formed on each of a lateral side portion of the driving portion 8, a lateral side portion of the driver's seat 4, and a rear side portion of the driving portion 8. Is installed.

The power from the output shaft 11 of the engine 2 is transmitted to the radiator cooling fan 6 via the forward / reverse switching mechanism A. That is, as shown in FIGS. 1 and 3, the first transmission belt 12 that is constantly rotated by the output shaft 11 is stretched, and the first transmission belt 12 is extended.
Of the normal rotation pulley 13 which can be switched between a state where it is pressed against the inner peripheral surface of the first drive belt for driving rotation and a state where it is separated from the transmission for cutting off transmission, and a state where the normal rotation pulley 13 is pressed against the outer peripheral surface of the first transmission belt 12 for driving rotation thereof Then, the second transmission belt 16 is wound and stretched around the reverse rotation pulley 14 and the driven pulley 15 of the cooling fan 6, which can be switched to a state in which the transmission is cut off. The reverse rotation pulley 14 and the reverse rotation pulley 14 are provided so as to be switchable to the transmission state in a contradictory manner to constitute the forward / reverse rotation switching mechanism A. More specifically, the first transmission belt 12 is wound around a drive pulley 17 mounted on the engine output shaft 11, a driven pulley 19 for a water pump 18 for circulating engine cooling water, and a driven pulley 21 for a dynamo 20, respectively. The support shaft 22 of the cooling fan 6 is arranged on the same axis as the driven pulley 19 for the water pump. A pulley support member 24 is fitted onto the fan support shaft 22 so as to be relatively rotatable around the support shaft center, and the normal rotation pulley 13 and the reverse rotation pulley 14 are supported on the pulley support member 24. Then, each pulley 13, 14 and the cooling fan 6
The second transmission belt 16 is wound and stretched around the driven pulley 15, and the normal rotation pulley 13 and the reverse rotation pulley 14 are respectively configured to have a double pulley structure.
One side pulley portions 13a and 14a of 14 are arranged at positions where they can be pressed into contact with and separated from the first transmission belt 12. The pulley supporting member 24 urges the operation arm 24a integrally formed with the pulley 25 in a direction in which the normal rotation pulley 13 is pressed against the second transmission belt 16 by the spring 25, and the operation arm 24a is urged by the spring 25. By driving the electric cylinder CY against the above, the forward rotation pulley 13 is separated from the second transmission belt 16, and the reverse rotation pulley 14 is switched so as to be in pressure contact with the second transmission belt 16. In this way, the cooling fan 6 is rotated in reverse every time the pre-mowing processing section is moved upward, and dust attached to the radiator suction section is blown outward in accordance with the normal radiator cooling operation (FIG. 2). (A), (b)
reference).

At the time of switching from the normal rotation state or the reverse rotation state to the other switching state during the forward / reverse rotation switching operation, any one of the pulleys 13 and 1 is provided in the middle thereof.
4 also includes a neutral state maintaining means B for maintaining the neutral state in which the first transmission belt 12 is not in pressure contact for a predetermined time. That is, the electric cylinder CY is driven by the control device 27 based on the operation of the manual operation tool 26, and a control system is configured to switch to the reverse rotation state.
7 is provided with the neutral state maintaining means B. At the middle position during the state switching operation, the operation arm 24
a is the first transmission belt 12 for both pulleys 13 and 14.
A limit switch SW is provided to detect that the neutral position does not come into contact with the electric cylinder CY, and when a signal from the limit switch SW is input during the switching control for the electric cylinder CY, the control device 27 causes the electric cylinder CY to enter. Is stopped at that position, and the state is maintained for a predetermined time.

The detection of the neutral state may be made by attaching a potentiometer to the pivotal support portion of the pulley supporting member 24 instead of the limit switch.

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

[Brief description of drawings]

FIG. 1 is a control system diagram of a forward / reverse switching mechanism.

FIG. 2 is a side view of an essential part showing a forward / reverse switching state.

FIG. 3 is a simplified front view of a forward / reverse switching mechanism.

FIG. 4 is a front view of the driving part of the combine.

[Explanation of symbols]

 2 engine 6 cooling fan 11 output shaft 12 first transmission belt 13 forward rotation pulley 14 reverse rotation pulley 15 driven pulley 16 second transmission belt A forward / reverse switching mechanism B neutral state maintaining means

Claims (1)

[Claims] 1. An engine cooling device configured to transmit power from an output shaft (11) of an engine (2) to a cooling fan (6) of a radiator (5) via a forward / reverse switching mechanism (A). Therefore, the first transmission belt (12), which is constantly driven to rotate by the output shaft (11), is stretched, and the first transmission belt (12) is pressed against the inner peripheral surface of the first transmission belt (12) and separated from the state of being driven and rotated. Forward drive pulley (13) that can be switched to a state in which transmission is cut off by means of the above, and the first transmission belt (12)
A reverse rotation pulley (14) that can be switched between a state in which it is pressed against the outer peripheral surface of the vehicle and driven to rotate, and a state in which it is separated and transmission is cut off.
A second transmission belt (16) is wound and stretched around the driven pulley (15) of the cooling fan (6), and the normal rotation pulley (13) and the reverse rotation pulley (1).
4) and 4) are provided so that they can be switched to a transmission state in a contradictory manner to configure the forward / reverse rotation switching mechanism (A), and when the forward / reverse rotation switching operation is performed, the normal rotation state or the reverse rotation state is switched to another switching state. At this time, in the middle thereof, an engine cooling device provided with a neutral state maintaining means (B) for maintaining for a predetermined time a neutral state in which neither of the pulleys (13) and (14) is in pressure contact with the first transmission belt (12). .