JP2008138755A - Multipurpose work vehicle power transmission mechanism - Google Patents

Abstract

A sub-transmission device is combined with a high / low speed hydraulic clutch and a gear transmission clutch so that a smooth shift from a low speed to a high speed can be achieved.
A hydraulic transmission clutch comprising a high-speed hydraulic clutch and a low-speed hydraulic clutch is provided at the lower transmission position of the hydraulic transmission, and a gear transmission clutch comprising a high-speed gear clutch and a low-speed gear clutch is provided at the lower transmission position. Low-speed gear clutch> High-speed hydraulic clutch / low-speed gear clutch> Low-speed hydraulic clutch / high-speed gear clutch> High-speed hydraulic clutch / high-speed gear clutch The gear ratio of the high-speed hydraulic clutch / high-speed gear clutch enables shifting in four stages from low to high. A sensor for detecting the shift operation position of the gear shift lever for operating the gear shift clutch is provided, and when a shift is made from the low speed gear clutch to the high speed gear clutch based on a signal from the sensor, the gear shifts automatically to the low speed hydraulic clutch, and from the high speed gear clutch to the low speed gear When shifting to the clutch, it is controlled to automatically shift to the high speed hydraulic clutch.
[Selection] Figure 7

Description

  The present invention relates to a multi-purpose work vehicle that travels with various work machines used for road work such as snow removal, cleaning and watering on the road, lawn mowing or other agricultural work.

The multi-purpose work vehicle is provided with a PTO output shaft for driving the work machine on the front side or the rear side of the machine body as described in JP-A-2005-212665 and JP-A-2005-343187. The speed can be changed from ultra low speed to high speed for running on the road.
JP 2005-212665 A JP 2005-343187 A

  Multi-purpose work vehicles and tractors use a diesel engine as the prime mover, but since the diesel engine has a narrow speed change range, it can be rotated at a constant rotational speed to obtain a stable output, and this constant rotation is connected to the engine output shaft. The speed is changed to the required axle speed. In the transmission case, the rotation of the engine output shaft is directly input to the hydraulic transmission, and the output from the hydraulic transmission is further increased / decreased by a sub-transmission using a gear shift.

  In the present invention, a power transmission mechanism in a transmission case is provided in which a high and low speed hydraulic clutch and a gear transmission clutch are combined with a sub-transmission device so that the traveling speed can be changed in multiple stages and the speed can be changed smoothly from a low speed to a high speed. Is an issue.

The problems of the present invention are solved by the following means.
According to the first aspect of the present invention, the rotation of the input shaft 19 that receives the rotation of the engine output shaft is steplessly changed by the hydraulic transmission device 1, and the high-speed hydraulic clutch YH and the low-speed hydraulic clutch are subordinate to the transmission of the hydraulic transmission device 1. A hydraulic transmission clutch 2 consisting of YL is provided, and a gear transmission clutch 3 consisting of a high-speed gear clutch GH and a low-speed gear clutch GL is provided at the lower transmission position. Clutch GL> low speed hydraulic clutch YL / high speed gear clutch GH> gear ratio between high speed hydraulic clutch YH and high speed gear clutch GH allows gear shifting in four stages from low speed to high speed and gear shift lever for operating gear shift clutch 3 4 sensors 90H and L for detecting the shift operation position are provided, and a low speed is detected by signals from the sensors 90H and L And automatic shift to the low speed hydraulic clutch YL when shifting from Akuratchi GL speed gear clutch GH, characterized in that control the order to the automatic transmission speed hydraulic clutch YH When shifting from the high speed gear clutch GH in low gear clutch GL.

  The constant rotation of the input shaft 19 is smoothly shifted with a constant shift width by the hydraulic transmission device 1, and the shift width is changed to high speed and low speed by the hydraulic shift clutch 2 of the high speed hydraulic clutch YH and the low speed hydraulic clutch YL. The gear shift clutch 3 of the high-speed gear clutch GH and the low-speed gear clutch GL is shifted to a high speed and a low speed, and in total, the low-speed hydraulic clutch YL, the low-speed gear clutch GL> the high-speed hydraulic clutch YH, the low-speed gear clutch GL> the low-speed hydraulic clutch YL. High-speed gear clutch GH> Gear ratio relationship between high-speed hydraulic clutch YH and high-speed gear clutch GH, that is, it is possible to shift in four stages from low speed to high speed from the first speed to the fourth speed. The hydraulic transmission 1 is switched from high to low and in order from the first speed to the fourth speed.

  According to the first aspect of the present invention, the rotation of the input shaft 19 input at a constant rotation is largely shifted in four stages, and the transmission is shifted to the unrecognized floor by the hydraulic transmission 1 at each shift stage. A smooth shift can be performed in a wide shift range, and the gear shift clutch 3 is interposed in the shift path, so that the manufacturing cost is low. In addition, as the gear shift lever 4 is switched between high and low, the hydraulic shift clutch 2 is automatically switched between high and low so that the speed can be changed smoothly from the second speed to the third speed or from the third speed to the second speed.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an overall view of a multi-purpose work vehicle. The cabin 5 is provided with a cockpit 7 on the front side of the aircraft, the engine 6 is mounted on the rear of the aircraft, and the front and rear wheels 8 and 9 are mounted on the bottom. ing.

  Inside the cabin 5, a steering handle 10 is erected at the front center of the cockpit 7, a PTO clutch lever 11 and a shift lever 4 are provided on the left and right sides of the steering handle 10, and a brake pedal 12 is provided at the foot. . In addition, a PTO output shaft 13 for driving the work machine projects from the center of the left and right front wheels 8 below the cabin 5. A sensor 97 for detecting depression is provided below the brake pedal 12.

  On the rear side of the cabin 5, a cargo bed plate 92 is attached via a rubber mount 91 above the engine 6 with a filter 93 sandwiched between the chassis 95. The filter 93 is opened at its left and right outer ends, and a blocking plate 94 is attached to the rear outer end to suck air from the left and right sides, so that exhaust from the rear is not sucked.

Next, the internal structure of the transmission case 14 that transmits the driving force to the front and rear wheels 8 and 9 and the PTO output shaft 13 will be described with reference to FIGS.
As shown in FIG. 4, the transmission case 14 has a configuration in which four hollow cases of a front case 15, a connecting case 16, an intermediate case 17, and a rear case 18 are connected, and an engine 6 is connected to an input shaft 19 that is pivotally supported by the rear case 18. , The rotation of the input shaft 19 is transmitted to the first relay shaft 23 by the speed increasing gears 21 and 22 in the input case 20, and further increased by the speed increasing gears 24 and 25. The hydraulic input shaft 38 of the hydraulic transmission 1 is spline fitted to the gear 25. The connecting case 16 connects the conventional front case 15 and the intermediate case 17 to lengthen the mission case 14, and the front case 15, the intermediate case 17, and the rear case 18 are shared with the conventional mission case, so that the production cost is increased. Can be lowered.

  The input case 20 including the speed increasing gears 21 and 22 and the speed increasing gears 24 and 25 is provided to increase the output rotation speed of the diesel engine 6 so as to enable high-speed traveling. The transmission mechanism can be stored in the case 14. As shown in FIG. 6, if the input case 20 is a sealed case and oil is supplied from an oil supply pipe that leads to the outside of the transmission case 14, the transmission gears 21, 22, 24, and 25 are repaired when the transmission is repaired. Since only the input case 20 can be removed without draining the oil in the case 14, the work becomes easy.

Inside the hydraulic transmission 1, the output is largely steplessly changed by the hydraulic shift and is output to the two shafts of the PTO drive shaft 26 and the travel drive shaft 27.
A PTO gear shaft 28 is connected to the PTO drive shaft 26, a gear 29 of the PTO gear shaft 28 is engaged with a gear 31 loosely fitted to the second relay shaft 30, and a PTO clutch in which the gear 31 is mounted on the PTO shaft 32. It meshes with 34 gears 33. The PTO clutch 34 interrupts rotation transmission from the gear 33 to the PTO shaft 32.

A PTO extension shaft 35 is connected to the PTO shaft 32, and a gear 36 of the PTO extension shaft 35 is engaged with a clutch gear 37 spline-fitted to the PTO output shaft 13 to drive the PTO output shaft 13. (See Figure 4)
7 shows details of the PTO clutch 34. When the clutch is engaged, the clutch disc 88 is connected and the casing 86 is rotated and transmitted. However, when the clutch is disengaged, the clutch disc 88 is separated by the pressure of the return spring 87, and the casing 86 is separated. Make it free. At this time, a locking ring 85 that contacts the boss 81 of the connecting case 16 is attached to the outer periphery of the casing 86 in order to prevent the casing 86 from being attached.

  A third relay shaft 39 is connected to the travel drive shaft 27, and gears 41 and 42 are meshed with a gear 40 fixed to the third relay shaft 39 and transmitted to the fourth relay shaft 43. A main gear shaft 44 is connected to the fourth relay shaft 43.

A large gear 45 and an intermediate gear 46 are integrally fixed to the main gear shaft 44, and a sub gear shaft 47 is separated and supported rotatably on the extension of the main gear shaft 44. A small gear 48, a large gear 74, and a traveling transmission gear 75 are integrally fixed to the sub gear shaft 47. Accordingly, the large gear 45 and the middle gear 46 rotate in the same direction, and the small gear 48, the large gear 74, and the travel transmission gear 75 receive rotation from a clutch gear 77 described later. (See Figure 7)
The large gear 45 meshes with the gear 50 of the high-speed hydraulic clutch YH mounted on the clutch shaft 49, the middle gear 46 meshes with the gear 53 of the low-speed hydraulic clutch YL mounted on the clutch shaft 49, and the rotation of the main gear shaft 44 causes the clutch shaft 49 to rotate. To high speed or low speed.
A spline shaft 76 is spline-fitted on the extension of the clutch shaft 49, and a clutch gear 77 is spline-fitted on the spline shaft 76 to transmit the rotation of the clutch shaft 49 to the clutch gear 77. Further, the boss portion 81 of the connecting case 16 that supports the clutch shaft 49 is provided with hydraulic holes 82, 83, 84 that communicate with the hydraulic holes of the clutch shaft 49, and hydraulic oil is supplied to the high-speed hydraulic clutch 51 and the low-speed hydraulic clutch 52. I am trying to send it.

  A large gear 78 and a small gear 79 are formed in the clutch gear 77, and the large gear 78 meshes with the small gear 48 of the sub gear shaft 47 to increase the transmission speed to form a high speed gear clutch GH, or the small gear 79 is a sub gear. The low speed gear clutch GL is configured by meshing with the large gear 74 of the shaft 47 and decelerating, or the gear shift clutch 3 is configured such that the large gear 78 and the small gear 79 are both turned to turn off the power. Yes.

  The travel transmission gear 75 of the clutch shaft 49 is engaged with the travel gear 56 spline-fitted to the bevel gear shaft 62 loosely fitted to the spline shaft 76 to drive the bevel gear shaft 62. The bevel gear 63 of the bevel gear shaft 62 transmits the driving force to the bevel gear attached to the axle of the front wheel 8.

  The bevel gear shaft 62 is a four-speed transmission from the high speed hydraulic clutch YH to the large gear 78 of the clutch gear 77 and the small gear 48 of the sub gear shaft 47, or the small gear 79 of the clutch gear 77 and the sub gear shaft 47 of the sub gear shaft 47. Third gear by transmission to the large gear 74, second gear by transmission from the low speed hydraulic clutch YL to the large gear 78 of the clutch gear 77 and the small gear 48 of the sub gear shaft 47, or small gear of the clutch gear 77 from the low speed hydraulic clutch YL. 79 and the sub gear shaft 47 are rotated at any one speed by transmission to the large gear 74.

  Further, the rotation of the bevel gear shaft 62 is transmitted from the traveling gear 56 to the small gear portion 57 of the large and small gear 59 attached to the PTO shaft 32, and is further appropriately controlled by the clutch gear 60 of the rear wheel drive shaft 61 engaged with the large gear portion 58. The driving force can be transmitted to the rear wheel 9.

Since the traveling gear 56 is transmitted to the bevel gear shaft 62 and is transmitted to the rear wheel drive shaft 61 via the large and small gears 59, the transmission configuration is simplified to prevent it from becoming longer in the front-rear direction.
Note that either the high speed hydraulic clutch YH or the low speed hydraulic clutch YL is kept on via a solenoid in response to a control signal from the controller. A switch 96 for detecting depression of the brake pedal is provided. In response to the depression signal, the power to the solenoids of the high-speed hydraulic clutch YH and the low-speed hydraulic clutch YL is cut off so that both clutches 51 and 52 are neutral. By applying the brake in this neutral state, it can be quickly stopped and the gear shift clutch 3 can be switched smoothly.

  The boss portion 81 of the connecting case 16 that supports the clutch shaft 49 is provided with hydraulic holes 82, 83, 84 that communicate with the hydraulic holes of the clutch shaft 49, and hydraulic oil is supplied to the high-speed hydraulic clutch YH and the low-speed hydraulic clutch YL. I am trying to send it.

  FIG. 8 shows the shift lever 4, and the gear shift clutch 3 is shifted to the high-speed gear clutch or the low-speed gear clutch by rotating the shift groove 96 from the central neutral position N to the front and rear H and L. When the speed increasing button 81 provided on the head of the grip 80 of the speed change lever 4 is pressed, the high speed hydraulic clutch YH is engaged, and when the speed reducing button 82 is pressed, the low speed hydraulic clutch YL is engaged.

  Further, sensors 90H and L for detecting the position of the speed change lever 4 are provided in the speed change groove 96, and when the speed change lever 4 moves from the low speed position L to the high speed position H, the low speed hydraulic clutch YL is turned on and becomes the third speed. When moving from the high speed position H to the low speed position L, the microcomputer control is performed so that the high speed hydraulic clutch YH is engaged and the speed becomes the second speed. When the high-speed hydraulic clutch YH is engaged, if the accelerator pedal 98 is stepped on more than 3/4 and the hydraulic transmission is at a high speed, the speed is reduced once to reduce the shift shock.

When the lever 4 presses the deceleration button 82 at the low speed position L, the first speed is achieved. When the lever 4 presses the speed increase button 81 at the high speed position H, the fourth speed is achieved.
FIG. 9 shows an accelerator pedal 98 which is connected to the throttle of the engine 6 by a throttle cable 99 to increase the rotation of the engine and is connected to the trunnion shaft of the hydraulic transmission 1 to increase the rotation. As shown in FIG. 10, the accelerator pedal 98 is actuated at all angles by operating the throttle, and the trunnion shaft of the hydraulic transmission 1 is rotated by a 3/4 stroke. Accordingly, only the rotation of the engine 6 rises within a 1/4 range from the start of the stepping, and the hydraulic transmission 1 starts to increase when the stepping is further performed, so that the oil is sufficiently supplied to the hydraulic transmission 1.

  The hydraulic transmission 1 detects the engine overheat in advance, and when the temperature sensor provided in the engine 6 reaches a temperature just before the overheat, even if the accelerator pedal 98 is depressed to increase the speed, the acceleration signal is ignored and the load is ignored. I try to avoid the increase.

  Further, when the temperature sensor provided in the engine 6 reaches a temperature just before overheating (for example, a temperature about 3 ° C. lower than the overheating temperature), the warning lamp provided on the operation display panel blinks, and when the overheating temperature is reached, the warning lamp is continuously lit. And buzzer.

It is a side view of a multipurpose work vehicle. It is a partial enlarged side view of a multipurpose work vehicle. It is a whole sectional side view of a mission case. It is a partially expanded side sectional view of a mission case. It is a partially expanded side sectional view of a mission case. It is a partially expanded side sectional view of a mission case. It is a partial enlarged perspective view. It is a perspective view which shows a motion of a transmission lever. It is a side view which shows a motion of an accelerator pedal. It is a schematic diagram which shows a motion of an accelerator pedal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic transmission device 2 Hydraulic clutch 3 Gear transmission clutch 19 Input shaft YH High speed hydraulic clutch YL Low speed hydraulic clutch GH High speed gear clutch GL Low speed gear clutch 90H, L Sensor

Claims (1)

The rotation of the input shaft (19) that receives the rotation of the engine output shaft is steplessly shifted by the hydraulic transmission (1), and the high-speed hydraulic clutch (YH) and the low-speed hydraulic clutch ( YL) is provided with a hydraulic transmission clutch (2), and a lower gear transmission is provided with a high-speed gear clutch (GH) and a low-speed gear clutch (GL). Gear clutch (GL)> High speed hydraulic clutch (YH) / Low speed gear clutch (GL)> Low speed hydraulic clutch (YL) / High speed gear clutch (GH)> Gear ratio of high speed hydraulic clutch (YH) / High speed gear clutch (GH) Therefore, a sensor (9) that enables gear shifting in four stages from low speed to high speed and detects the gear shift operation position of the gear gear shift lever (4) that operates the gear gear shift clutch (3). H, L), and when a shift from the low-speed gear clutch (GL) to the high-speed gear clutch (GH) is made by a signal from the sensor (90H, L), the low-speed hydraulic clutch (YL) is automatically shifted to the high-speed gear clutch (GH). ) To a low speed gear clutch (GL), the power transmission mechanism of the multipurpose work vehicle is controlled to automatically shift to a high speed hydraulic clutch (YH).

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