JPH0526688B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a steering bar handle located in front of a straddle-type driver's seat with a manual throttle operator, and an automatic centrifugal clutch that controls engine output. This invention relates to a vehicle for traveling on rough terrain that can be output as a PTO output for driving external equipment through the PTO output.

(Background of the invention) The steering bar handle located in front of the straddle-type driver's seat is equipped with a throttle operator that can be operated with the hand holding the handle grip, and the engine output is used to drive external equipment via an automatic centrifugal clutch. of
It can be output as a PTO (Power Take Off) output, and this PTO output can be used for lawn mowers, sprayers, etc.
A vehicle for traveling on rough terrain that can drive a cultivator or the like is being considered. In this type of vehicle, the PTO
When switching to PTO mode to extract power, if the engine is rotating faster than the automatic centrifugal clutch engages, the rotation will suddenly be transmitted to the connected external equipment. Therefore, there was a problem that external equipment could be damaged.

(Object of the Invention) The present invention has been made in view of the above circumstances, and when switching to PTO mode, the engine is prevented from reaching a speed higher than the speed at which the automatic centrifugal clutch is engaged, and the connected external To provide a vehicle for traveling on rough terrain that can reliably prevent equipment from suddenly rotating and damaging external equipment.

(Structure of the Invention) According to the present invention, this object is achieved by providing a steering bar handle located in front of the straddle-type driver's seat with a throttle operator that can be operated manually while grasping the handlebar grip, so that the output of the engine can be automatically controlled by centrifugal control. In an off-road vehicle that can be output as a PTO output for driving external equipment via a clutch,
A manual switching lever for switching on and off the PTO output and the throttle operator are arranged on the same side and separated from each other with respect to a center line passing in the longitudinal direction of the vehicle body so that they cannot be operated at the same time. Achieved by a terrain steering vehicle.

(Example) Fig. 1 is a partially cutaway plan view of an embodiment of the present invention, Fig. 2 is a perspective view of the power unit, Fig. 3 is an exploded view showing the power transmission system, and Fig. 4 is a switching diagram. It is an explanatory diagram of the operation of the lever.

In FIG. 1, an off-road vehicle 10 includes two steering front wheels 12 and two driving rear wheels 14. These front wheels 12 and rear wheels 14 are equipped with wide ultra-low pressure tires (so-called balloon tires).
A running engine 16 is mounted near the center of the vehicle body. A steering bar handle 18 is disposed above between the front wheels 12, and behind this bar handle 18 a fuel tank 20 and a straddle type driver seat 22 are provided.
are arranged in sequence. The driver sits astride this driver's seat 22. A throttle lever 18a as a manual throttle operator is attached to the right side of the bar handle 18 near the handle grip, and the throttle lever 18a can be operated with the thumb of the hand gripping the handle grip.

As shown in FIG. 3, the engine 16 is configured to transmit the rotation of a crankshaft 24 to an output shaft 34 via an automatic centrifugal clutch 26, a multi-disc clutch 28, a multi-stage transmission 30, and a bevel gear 32. . This rotation of the output shaft 34 is transmitted by a drive shaft 36 to a final reduction gear 40 provided on the rear wheel shaft 38. Note that the multi-disc clutch 28 is connected to the transmission 30.
The transmission is temporarily interrupted at the moment of gear change in conjunction with the operation of the gear change pedal 30a (FIG. 1). Further, the multi-speed transmission 30 is capable of selecting a neutral position.

A PTO output extraction mechanism 42 is built into the engine 16. This mechanism 42 includes gears 44, 46 driven by the crankshaft 24 via the centrifugal clutch 26 and the gear 28a of the clutch 28.
a shaft 48 rotatably supporting the gear 46; a slider 52 splined to the shaft 48 and forming a dog clutch 50 together with the gear 46; and a mechanical automatic centrifugal governor 54 provided on the shaft 48.
and a bevel gear 56 that transmits the rotation of the shaft 48 to the shaft 55. The rotation of the shaft 55 is via the drive shaft 58.
It is transmitted to the PTO output shaft 60. Note that this PTO output shaft 60 is supported by the case of the final reduction gear 40, as shown in FIG.

A manual switching lever 62 is provided on the right side of the engine 16, that is, on the same side as the throttle lever 18a with respect to the center line A (FIG. 1) passing in the longitudinal direction of the vehicle body. This switching lever 6
2 is an upright low-speed running position a as shown in FIG.
It is possible to select from three positions: PTO mode position b, which is tilted forward, and normal driving position c, which is tilted backward. A plate 62a in which two arcuate long holes are formed is fixed to the switching lever 62.

A switching shaft 64 is provided at the rear of the engine 16, and a lever 6 is fixed to the upper end of this switching shaft 64.
6 is connected to one elongated hole in the plate 60a of the switching lever 62 by a link 68. this link 6
8 is biased to the right (in the PTO OFF direction) in FIG. 4, and is locked to the rear end of the elongated hole at the upright position a of the switching lever 62. Another lever 70 is attached to the switching shaft 64.
(FIG. 3) is fixed, and the pivoting end of this lever 70 engages with a fork 72 that moves the slider 52. Therefore, in the PTO mode in which the switching lever 62 is moved to the forward tilted position b, the link 68 is pulled to the left (in the PTO ON direction) in FIG.
rotates counterclockwise in FIG. 3, the fork 72 and slider 52 move to the left, and the dog clutch 50 engages. Therefore, when the crankshaft 24 reaches a predetermined rotational speed or higher, the automatic centrifugal clutch 28 is engaged, and the rotation of the crankshaft 24 is controlled by the centrifugal clutch 26, gears 28a, 44, 46, slider 52,
It is transmitted to the PTO output shaft 60 via the shaft 48, bevel gear 56, shaft 55, and drive shaft 58. When the switching lever 62 is placed in the upright position a or the rearward tilted position c, the link 68 returns to the position shown in FIG. 4, the dog clutch 50 is disengaged, and the PTO output shaft 60 is stopped.

As shown in FIG. 3, the governor 54 includes a disc 74 integrated with the slider 52, a weight 76 supported by the disc 74, and a spline-coupled shaft 48, which is slidably held in the axial direction. A slider 78 is provided. A lever 80 biased by a spring comes into contact with the slider 78, and a lever 82 rotates together with this lever 80.

84 is a carburetor, and this carburetor 84 is connected to the throttle lever 18a provided on the bar handle 18 and the governor 54 according to the operation of the switching lever 62.
selectively interlocks with the lever 82. That is, when the switching lever 62 is moved to the forward tilting position b (PTO mode), the movement is transmitted to the slider 52 by the link 68, the dog clutch 50 is engaged, and the slider 78 is moved to the lever biased by the spring. 80, the clutch is moved to the dog clutch 50 side. Therefore, the carburetor 84 is once fully opened. However, the movement of the link 68 is transmitted to the carburetor 84 via the bell crank 86 and the link 88, and the movement of the lever 82 of the governor 54 is transmitted to the carburetor 84 by the wire 90. is immediately controlled at a constant speed by the governor 54. Also, move the switching lever 62 to the upright position a.
Alternatively, when the rear tilt position c is set, the movement of the throttle lever 18a is transmitted to the carburetor 84, and the vehicle can travel at a speed corresponding to the amount of operation of the throttle lever 18a.

In this embodiment, a high-low speed switching mechanism is incorporated in the final reduction gear 40. That is, as shown in FIG. 3, the final reduction gear 40 includes an input shaft 92 rotated by the drive shaft 36, and two gears 94 and 96 having different numbers of teeth rotatably held on the input shaft 92. , a gear 1 fixed to the intermediate shaft 98 and meshing with each of the gears 94 and 96;
00 and 102, a gear 104 that meshes with a gear 100, a small bevel gear 106 fixed to this gear 104, and a large bevel gear 108 that meshes with this small bevel gear 106. A slider 110 located between gears 94 and 96 is mounted on the input shaft 92 so as to be slidable in the axial direction. The slider 110 and each of the gears 94 and 96 form a dog clutch, and when the lever 112 is rotated, the slider 110
selectively engages one gear 94 or 96. Note that this lever 112 is connected to the other elongated hole provided in the plate 62a of the switching lever 62 by a link 114. Furthermore, this link 114
is biased to the left (LO direction) in FIG. 4, and is locked to the front end of the elongated hole at the upright position a of the switching lever 62.

As a result, when the switching lever 62 is in the upright position a or the forward tilted position b, the link 114 is in the low speed position (LO) shown in FIG. Now, link 114 is pushed to the right in Figure 4 to the high speed position (HI).
The slider 110 engages with the gear 94 on the high speed side.

Therefore, during normal running, the switching lever 62 is placed in the rearward tilted position c, and at this time the engine 16 runs under the control of the throttle lever 18a. Further, when towing a heavy load, if the switching lever 62 is set to the upright position a, the reduction ratio of the final reduction gear 40 is increased, a large driving force is obtained, and the speed is controlled by the throttle lever 18a. Furthermore, when taking out the PTO output, the switching lever 62
is set to the forward tilt position b, and at this time the engine 16 is operated at a constant speed by the governor 54 and the final reduction gear 40 is set to a high reduction ratio. Since the switching lever 62 is positioned synchronously with the throttle lever 18a, when switching the switching lever 62, you must always take your hand off the travel handle 18, and the throttle lever 18
Since engine a automatically returns to the idle position, engine 16 is at idling speed. For this reason
When switching to PTO mode, the engine 16 will never exceed the speed at which the automatic centrifugal clutch 26 engages. In addition, in this PTO mode, transmission 3
If 0 is set to the neutral position, external equipment can be driven while the vehicle is stopped, and if set to a position other than neutral, external equipment can be driven while the vehicle is running.

In FIG. 2, 18b is a governor control lever attached to the left side of the steering handle 18. This lever 18b is connected to the carburetor 84 by a wire so that the engine speed can be changed to a speed other than the governor set speed in PTO mode. Note that the lever 18b can be fixed continuously or discontinuously at an appropriate rotational position. The lever 18b is also used to fully open the throttle valve of the carburetor 84 to improve starting performance when starting the engine in PTO mode. In other words, in this embodiment, when switching to PTO mode, slider 78
(Fig. 3) moves and the throttle valve is once fully opened. However, since the throttle valve remains in the fully open position before the engine starts, starting performance is poor if the engine is started as it is. Therefore, the lever 18b is used to fully open the throttle valve at this time.

The engine speed control method in PTO mode is as follows:
In addition to controlling the throttle valve opening of
It is also possible to control the spring force of the spring that biases the lever 80 of the governor 54. Therefore, lever 18
The speed control in the PTO mode may be performed by controlling the spring force of the lever 80 using b or another operator.

In this embodiment, the switching lever 62 is
Not only PTO mode switching but also final reduction gear 40
Although high constant speed switching is also possible, it goes without saying that the present invention also includes a case where high speed and low speed switching is not performed.

(Effects of the Invention) As described above, the present invention allows the switching lever for switching the PTO mode and the throttle operator to be separated from each other on the same side with respect to the center line passing in the longitudinal direction of the vehicle body so that they cannot be operated at the same time. Because of this arrangement, your hand always leaves the throttle operator when operating the switching lever. Therefore, when switching to PTO mode, the engine is at idling speed, the automatic centrifugal clutch is disengaged, and the PTO output shaft does not rotate. Therefore, when switching to PTO mode, PTO
It is possible to reliably prevent external equipment connected to the output shaft from suddenly rotating and causing damage or damage to the external equipment.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view of an embodiment of the present invention, Fig. 2 is a perspective view of the power unit, Fig. 3 is an exploded view showing the power transmission system, and Fig. 4 is an explanation of the operation of the switching lever. It is a diagram. 16... Engine, 18... Steering bar handle, 18a... Throttle lever, 22... Straddle type driving seat, 26... Automatic centrifugal clutch, 60
...PTO output shaft, 62...Switching lever, A...
...center line.

Claims (1)

[Claims] 1. A steering bar handle located in front of the straddle-type driver's seat is equipped with a throttle operator that can be manually operated while grasping the handle grip, and the engine output is used to drive external equipment via an automatic centrifugal clutch. In an off-road vehicle that can be used as a PTO output, the manual switching lever that switches on and off the PTO output and the throttle operator are connected to the center line that runs in the longitudinal direction of the vehicle so that they cannot be operated at the same time. A vehicle for rough terrain steering, characterized in that the wheels are arranged on the same side and separated from each other.