KR19990029226A - Power Train of Work Machine - Google Patents

Abstract

As a power transmission device for a work machine which performs power transmission from the engine 9 to the traveling device 22, this power transmission device is

A gear-type forward and backward switching mechanism 25 that can be switched between the forward state, the neutral state, and the reverse state; And

A clutch mechanism (24) for switching the power to the forward / backward switching mechanism (25) to a power transmission state or a non-power transmission state on the basis of the switching operation of the forward / backward switching mechanism (25).

The clutch mechanism 24,

By the pressing force of the spring 54 is switched to the power transmission state,

In response to the pressure oil supply to the clutch mechanism 24 by the pressure oil supply control means B, it is switched to the power non-transmission state against the pressing force of the spring 54, and

The pressure oil supply control means (B),

When the forward and backward switching mechanism 25 is in the neutral state, pressure oil is supplied to the clutch mechanism 24,

When the forward and backward switching mechanism 25 is in the forward state or the reverse state, the hydraulic oil is discharged from the clutch mechanism 24.

Description

Power Train of Work Machine

The present invention relates to a work machine such as a rice transplanter in which a power transmission system from an engine to a traveling device is retrofitted with a gear type forward and backward switching mechanism and a clutch mechanism for controlling power transmission to the forward and backward switching mechanism based on the forward and backward switching operation. It relates to a power train.

An advantage of the power transmission device of this type of work machine is that the clutch mechanism can be operated only by performing the forward / backward switching operation without turning the clutch mechanism on and off when the forward / backward switching is performed.

In the power transmission device of the conventional working machine having such an advantage, the forward gear and the reverse gear which are always engaged with and engaged with the lower or upper gear in the power transmission direction are mounted freely on the input shaft or the output shaft. Further, as a clutch mechanism, a forward clutch such as a hydraulic clutch for linking the forward gear to the input shaft or an output shaft based on the forward switching operation, and a reverse clutch such as a hydraulic clutch for linking the reverse gear to the input shaft or output shaft based on the reverse switching operation Is provided, and the forward / backward switching of a work machine is performed accordingly.

However, according to the conventional technique, since two clutches, a forward clutch and a reverse clutch, are required as the clutch mechanism for interlocking with the forward and backward switching operation, it is easy to cause the complexity of the power transmission structure and the cost increase.

An object of the present invention is to simplify the structure and reduce the cost of a clutch mechanism that operates in conjunction with forward and backward switching operations.

In order to achieve the above object, the power transmission device of the work machine according to the present invention is characterized by the configuration described in claim 1.

According to this configuration, with the switching of the forward and backward switching mechanism to the shift neutral state, the pressure oil supply control means switches the clutch to the power non-transmission state. On the other hand, with the switching of the forward and backward switching mechanism to the forward state or the reverse state, the oil pressure supply control means switches the clutch mechanism to the power transmission state. In the forward and backward switching, it is necessary to cut off power transmission from the engine to the traveling device once, but in the present invention, there is only one clutch for controlling power transmission. That is, there is only one clutch interlocked with the forward and backward switching operation.

In addition, the clutch is switched to the power non-transmission state in response to the pressure oil supply, and the clutch is switched to the power transmission state by the pressing force of the spring while the pressure oil is discharged. Therefore, power transmission in the forward and reverse states is performed. It can be reliably done.

That is, in the configuration in which the operation for switching the clutch to the power transmission state is also by the hydraulic oil supply, the pressure generated by the hydraulic pump due to the increase or decrease of the engine load causes the pressure contact pressure of the clutch plate to fluctuate, resulting in the power transmission state of the clutch. It may become unstable. In contrast, according to the present invention, the clutch plate is pressed against the clutch plate with excellent stability to maintain the clutch in a power transmission state. Therefore, the pressure contact pressure of the clutch plate is stabilized, and the power transmission state of the clutch is also stabilized, whereby the power transmission is stably performed.

Therefore, the clutch mechanism for interlocking power transmission in conjunction with the forward and backward switching operation can be made simple and inexpensive in one clutch, and the power transmission at the time of forward and reverse can be reliably and stably. You can do it. In addition, since clutch on operation is performed by the pressing force of the spring, the hydraulic pressure is not required for the on operation, which makes the device effective for low horsepower engines.

The operation of switching the clutch to the power non-transmission state against the pressing force of the spring may be configured to comply with the clutch pedal which is mechanically interlocked with the clutch. In this case, by operating the clutch pedal, the clutch of the clutch mechanism is switched to the power transmission state regardless of the state of the forward and backward switching mechanism. Therefore, the clutch for switching back and forth can be used as a traveling clutch for intermittent power transmission to the traveling device.

Therefore, the power transmission structure is further simplified according to the compatibility of the clutch.

Moreover, it is further advantageous in the following point that the hydraulic removal means which discharges the clutch operation pressure oil in a clutch to the outside accompanying operation at the time of engine start is provided.

In general, when starting the engine, the engine is started after switching the forward and backward switching mechanism to the shift-neutral state in order to prevent accidental oscillation accompanying the starting operation.

By the way, in the clutch mechanism, when the forward and backward switching mechanism is in the shift neutral state, the clutch is in a state in which the hydraulic oil is not transmitted and the hydraulic oil is supplied. This pressure oil acts as a load on the hydraulic pump of the hydraulic pressure supply control means, which is disposed near the engine and driven by engine power.

Therefore, when starting the engine, the load acts as an engine starting load, thereby lowering the startability of the engine.

In order to avoid the above state, in the present invention, the hydraulic removal means is provided so that the pressure oil in the clutch is discharged to the outside when an operation at engine startup is performed. Therefore, when the engine is started with the forward and backward switching mechanism switched to the shift neutral state, the load of the hydraulic pump can be made extremely small.

Therefore, while using the clutch mechanism in a power non-transmission state by the supply of pressure oil, it is possible to reduce the load caused by the hydraulic pump at the time of engine startup, and to improve engine startability.

In addition, when the pressure oil supply control means is provided as a valve at one end of the operation shaft for shifting the shift member, the member relating to the shift shift and the valve relating to supply and discharge of the hydraulic oil are operated integrally, so that the operation is assured. In this way, the valve body can be incorporated in one end of the operation shaft as the valve, and the valve body can be slidably formed along the valve case.

In this integrated configuration, when interlocking the valve with the forward and backward switching mechanism, there is no need to provide an interlocking means for linking the valve to the operation system of the forward and backward switching mechanism.

Furthermore, since one end of the operation shaft is directly formed in the valve body, it is sufficient to provide a valve case in constructing the valve.

Therefore, as the valve linkage is not required, the structure for interlocking the valve with the forward and backward switching mechanism can be simplified, and the valve can be linked with the forward and backward switching mechanism with high accuracy, and the valve structure according to the member compatibility Simplification is also planned.

Other features, operations, and effects of the present invention will become apparent by reading the preferred embodiments of the present invention with reference to the accompanying drawings.

1 is a side view of a riding type rice transplanter,

2 is a side view of the driving unit;

3 is a schematic front view showing a linkage state between the operation lever and the auxiliary transmission;

4 is a plan view of the rice transplanter front portion,

5 is a front view of the auxiliary shift lever,

6 is a schematic side view of a continuously variable transmission,

7 is a plan view of each shift state of the continuously variable transmission,

8 is a longitudinal sectional front view of an input of a continuously variable transmission;

9 is a longitudinal sectional front view of the control system of the continuously variable transmission;

10 is a plan view of an essential part of the operation system of the continuously variable transmission;

11 is a transverse plan view of a power train to a traveling device;

12 is a transverse plan view of the power train to the planting apparatus;

13 is a cross sectional view of a main portion of a power transmission system;

14 is a sectional view of the clutch mechanism;

15 is a cross-sectional view of each operating state of the clutch;

FIG. 16 is a cross-sectional view of each of the operating states of the shifter and the valve, and illustrating a pliability that allows movement of only one of the shifter and the valve; FIG.

17 is a front view of the peripheral speed lever attachment portion,

18 is a plan view of the lever guide,

19 is a side view of the linkage state between the peripheral speed lever and the auxiliary transmission;

20 is a hydraulic circuit diagram of the hydraulic supply control means,

21 to 24 are hydraulic circuit diagrams of the hydraulic pressure supply control means in different embodiments, respectively.

FIG. 25 is a front view showing an interlocking relationship between an operation shaft and a shifter in another embodiment of the filament shown in FIG. 16; FIG.

Explanation of symbols for main parts of the drawings

9: engine 10: transmission case 10a: input shaft

19: clutch pedal 22: traveling device 24: clutch mechanism

25: forward and backward switching mechanism 54: spring 57: forward gear

59: reversing gear 60: shift member 62: operating shaft

74: flow path 76: valve 76a: valve body

76b: valve case B: hydraulic oil supply control means EV: hydraulic removal means

T1: Euro Axis

EMBODIMENT OF THE INVENTION Hereinafter, the suitable Example of this invention is described according to the case where it applies to the riding type rice transplanter which is an example of a work machine.

The riding type rice transplanter shown in FIG. 1 is comprised by connecting the planting apparatus 2 to the rear part of the self-propelled machine 1 freely by the lifting mechanism via the link mechanism 3 and the hydraulic cylinder 4. As shown in FIG.

The self-propelled gas 1 is an engine covered with a bonnet 8 in the front part of a gas frame 7 having a left and right pair of steering front wheels 5 and a left and right pair of driving rear wheels 6. (9) and a transmission case (10) for supporting the drive front wheel (5), a passenger drive unit is arranged on the upper part of the base frame (7), and the driving rear wheel ( It is comprised by connecting the axle case 11 which supports 6).

In the rear part of the bonnet 8, the upper cover member 12 and the rear cover 13 which serve as an instrument panel are provided in succession.

As shown in FIG. 4, the passenger drive unit includes a peripheral speed lever having a steering wheel 14, a driver's seat 15, a boarding step 16, and an operation handle 17a for steering the driving front wheel 5. 17; an example of a transmission device), a sub transmission lever 18, and a clutch pedal 19 are provided. The steering post 20 supporting the steering wheel 14 penetrates the upper cover member 12 up and down. The peripheral speed lever 17 is attached to the support 21 in the upper cover member 12 through the hole 12a formed in the upper cover member 12 as shown in FIGS. 3 and 17, and the hole shaft core P1. ) Freely swing around. As shown in Figs. 4 and 5, the sub transmission lever 18 is freely swinged from side to side around the front-rear axial center P2 at the foot of the passenger drive unit. The hole shaft core P1 is a left-right shaft core.

As shown in Fig. 19, the peripheral speed lever 17 has a reverse position R at the rear end of the swing range, a neutral position N in the middle of the swing range, and the like by the forward and backward swing around the hole shaft center P1, It is comprised so that operation is possible in the advance area | region F of the front of a swing range.

As shown in FIG. 5, the sub transmission lever 18 is a high-speed "movement" position at one end of the swing range and a low-speed "work" in the middle of the swing range by the left and right swing around the front-rear axial center P2 as shown in FIG. It is comprised so that operation is possible by the position and the ultra-low speed "dump" position of the other end of a swing range. The neutral position N is set between the "move" position and the "work" position, and between the "work" position and the "dump skip" position, respectively.

As shown in FIG. 1, the traveling device 22 is composed of a driving front wheel 5 and a driving rear wheel 6. The power transmission device from the engine 9 to the travel position 22 is, as shown in FIG. 2, the input shaft 10a (FIG. 3) of the transmission case 10 from the output shaft 9b (FIG. 8) of the engine 9. It is provided with a belt-type continuously variable transmission 23 for transmitting power to the. As shown in FIG. 11, FIG. 12, in the transmission case 10, the clutch mechanism 24, the forward-backward switching mechanism 25, and the sub transmission 26 are provided in series in order of description. . Power is transmitted from the output shaft 26b of the sub transmission 26 to the transmission shaft 28 to the front wheel differential 27 and the axle case 11 via the output gear 29.

The continuously variable transmission 23 is configured as shown in Figs. The drive shaft 33 is provided concentrically with the output shaft 9b of the engine 9 in the frame 30 supporting the engine 9 and is supported through a pair of bearing 31. This drive shaft 33 is interlocked with the output shaft 9b of the engine 9 via a rubber coupling type joint 32. The drive shaft 33 is equipped with an output side pulley 34 which can freely adjust the belt winding diameter. The input shaft 10a of the transmission case 10 is equipped with an input side pulley 35 that can freely adjust the belt winding diameter. An endless belt for transmission 36 is wound over the output split pulley 34 and the input split pulley 35. The belt winding diameter of the output side pulley 34 is changed by sliding 34A of outer output pulley pieces with respect to the drive shaft 33 to the axial center direction of the drive shaft 33. As shown in FIG. The belt winding diameter of the input side pulley 35 is changed by sliding the inner input pulley piece 35A with respect to the input shaft 10a in the axial center direction of the input shaft 10a. 37 is a tension pulley that applies tension to the endless belt 36.

The belt winding diameter across the output split pulley 34 and the input split pulley 35 can be adjusted as follows. An annular pipe-shaped guide tube 38 is fixedly installed in a posture parallel to the axis of the drive shaft 33 and the input shaft 10a of the transmission case 10. An actuating shaft 39 is freely fitted to the guide tube 38 by the shifter 40 in and out along the axial direction. With the slide inward of the operating shaft 39, the output pulley piece 34A is pressurized inward against the belt tension, and the input pulley piece 35A is moved inward by the belt tension. This is permitted, and the continuously variable transmission 23 is speeded up. On the other hand, with the slide to the outside of the operating shaft 39, the output pulley piece 34A is allowed to move outward by the belt tension, and the input pulley piece 35A moves outward against the belt tension. The pressure is moved, and the continuously variable transmission 23 is decelerated.

A groove 41 is formed in the operating shaft 39, and the working shaft 39 is stopped rotationally as the pin 42 is engaged with the groove 41. A threaded portion 39A is formed at the inner end of the working shaft 39, and the pinion gear 43 is screwed to the screwed portion 39A to rotate in a state where the axial center position of the working shaft 39 is fixed. Thus, the operating shaft 39 slides. The pinion gear 43 meshes with the drive gear 44. The drive gear 44 is rotated forward and backward by the shifting motor 45.

The means for operating the continuously variable transmission 23 detects a slide position of the operation detection sensor 46 and a working shaft 39 using a potentiometer, which detects the swing position of the peripheral speed lever 17 (Fig. 10), a shift detection sensor 47 using a potentiometer for detecting a shift state of the continuously variable transmission 23 is provided. When the peripheral speed lever 17 is operated in the forward area F, the control device 48 is configured to shift the speed change motor 45 so that the detection result of the operation detection sensor 46 and the detection result of the shift detection sensor 47 coincide with each other. ) To control operation. As a result, the continuously variable transmission 23 is brought into a shift state corresponding to the operation position of the peripheral speed lever 17.

13 and 14 show a clutch mechanism 24 and pressure oil supply control means B for controlling the supply / discharge of the hydraulic oil to the clutch mechanism 24. The clutch mechanism 24 is composed of a multi-plate clutch 53 and a spring 54 that uses a disc spring to act on the housing 53A of the clutch 53 to pressurize the clutch 53 in an on state. have.

The input part of the clutch mechanism 24 is comprised by the 1st shaft T1 (corresponding to a flow path shaft) linked with the input shaft 10a of the transmission case 10 via gears 50 and 50 (FIG. 11). The output portion of the clutch mechanism 24 is composed of a forward output gear 51 and a reverse output gear 52 rotatably mounted on the first shaft T1. The clutch mechanism 24 controls the power transmission from the input section to the output section based on the forward and backward switching operation of the peripheral speed lever 17. That is, the clutch mechanism 24 is freely switched between the power transmission state (hereinafter referred to as on state) and the power non-transmission state (hereinafter referred to as off state).

Then, under the control of the pressure oil supply control means B, the piston part 55 and the first shaft T1 formed integrally with the clutch housing 53A with the switching of the forward and backward switching mechanism 25 to the neutral state. Of the hydraulic cylinder Cy consisting of the piston portion 55 and the cylinder portion 56 in the cylinder chamber C between the cylinder portion 56 (tube portion) installed in the state fixed in the axial direction. Pressure oil is supplied to the cylinder chamber (C). In response to the pressing force of the spring 54, the piston portion 55 is pressed and moved in the clutch off direction, and the clutch 53 is switched to the off state. On the other hand, under the control of the hydraulic oil supply control means B, with the switching of the forward and backward switching mechanism 25 to the forward state or the reverse state, the oil pressure in the cylinder chamber C is external (in the transmission case 10). Exit to Thereby, the piston part 55 returns to a clutch on direction by the pressing force of the spring 54, and the clutch 53 is switched to an on state.

The forward and backward switching mechanism 25 is configured as shown in Figs. On the input shaft 26a of the sub transmission 26, the forward gear 57 linked to the forward output gear 51 of the clutch mechanism 24 and the idler gears 58a and 58b wound around the idler shaft 58 are provided. A reverse gear 59 interlocked with the reverse output gear 52 of the clutch mechanism 24 is rotatably mounted. A shift gear 60 is rotatably mounted integrally with the input shaft 26a between the forward gear 57 and the reverse gear 59. The shift gear 60 meshes with both the forward gear 57 and the reverse gear 59 in a forward position interlocked with only the forward gear 57, the backward position interlocked with only the reverse gear 59, and interlocks with respect to both the forward gear 57 and the reverse gear 59. It is configured to shift freely to a neutral position.

In the above configuration, the forward state of the forward / backward switching mechanism 25 is changed from the forward output gear 51 of the clutch mechanism 24 to the forward / backward switching mechanism as the shift gear 60 meshes with the forward gear 57. The forward driving force is transmitted to the input shaft 26a through the forward gear 57 of (25). The reverse state of the forward / backward switching mechanism 25 is engaged from the reverse output gear 52 of the clutch mechanism 24 on the idle shaft 58 by engaging the shift gear 60 with the reverse gear 59. The reverse gear force is transmitted to the input shaft 26a by the idle gears 58a and 58b via the reverse gear 59 of the forward / backward switching mechanism 25. In the neutral state of the forward / backward switching mechanism 25, as the shift gear 60 is positioned at the neutral position, power is cut off between the clutch mechanism 24 and the forward / backward switching mechanism 25, whereby the input shaft 26a is applied. Appears as power is not being transmitted to. That is, there is a relationship as shown in Table 1 between the clutch mechanism 24 and the forward and backward switching mechanism 25.

Forward and backward switching mechanism (25) Forward state Neutral Backward Shift gear (60) Meshing with the forward gear (57), the power is forward gear (51) Not engaged Meshing with the reverse gear (59), the power is reversed on the idler shaft (58), and then to the reverse gear (52). Valve 76 of the hydraulic oil supply control means (B) OPEN CLOSE OPEN Hydraulic oil in clutch mechanism 24 Oil Refueling Oil Clutch Mechanism (24) Power transmission state (on) Power delivery status (off) Power transmission state (on) Spring (54) Under pressure Pressure oil against pressure Under pressure

The operation means for the forward and backward switching mechanism 25 is configured as shown in Figs. 2, 3, 13, 17, 19 (a) and (b).

As the operation shaft 62 for displacing the shift gear 60 through the shifter 61 is repositioned in a direction parallel to the input shaft 26a of the sub transmission 26, the shift gear 60 is moved forward. It is moved to the neutral, reverse position. The operation shaft 62 can be positioned in the forward position, the neutral position, and the reverse position, respectively, by the detent mechanism 63 using the ball. Moreover, the operation arm 64 which changes the position of the operation shaft 62 by oscillation, and the operation rod 65 which oscillates this operation arm 64 by pushing and pulling are provided. The training rod 65 is interlocked with the arm 66 fixed to the peripheral speed lever 17 via the link 67. In this configuration, when the peripheral speed lever 17 is located at the speed increasing start position f of the forward area F, the operation shaft 62 is positioned at the forward position, and the peripheral speed lever 17 is positioned at the neutral position ( When it is located at N), the operating shaft 62 is positioned at the neutral position, and when the peripheral speed lever 17 is positioned at the reverse position R, the operating shaft 62 is positioned at the reverse position. The link 67 is interlocked with the arm 66 via a link pin 68. The pin hole formed in the arm 66 has a linkage hole for oscillating the link 67 by transmitting the swing between the speed increasing start position f and the retracted position R of the peripheral speed lever 17 to the link 67 ( 69) and a non-interlocking hole 70 which does not transmit the swing 67 in the forward region F of the peripheral speed lever 17 to the link 67 and does not swing the link 67. As shown in FIG. The non-interlocking hole 70 is formed in circular arc shape along the periphery of the hole axis center P1. That is, since the distance from the link pin 68 to the hole shaft center 17 becomes constant while the link pin 68 is moved along the non-interlocking hole 70, even if the peripheral speed lever 17 is moved, the link ( 67 is not oscillated, and thus the operation rod 65 at the end of the link 67 is not moved.

3 and 17, the peripheral speed lever 17 is bent in the upper cover member 12 of the passenger drive section, and is freely swinged around the front-rear axial center P3. The regulating arm 71 is provided successively in the part located in the upper cover member 12 among the peripheral speed levers 17. As shown in FIG. In the upper cover member 12, as shown in FIGS. 3, 17, and 18, a lever guide 72 is provided. The lever guide 72 is a maximum speed at which the regulating arm 71 is engaged when the peripheral speed lever 17 is positioned at the maximum speed position fm to regulate and maintain further fluctuations of the peripheral speed lever 17. When the regulating section A1 and the peripheral speed lever 17 are positioned at the speed increasing start position f, the regulating arm 71 swings around the front-rear axial center P3 to speed up the peripheral speed lever 17. When the forward holding part A2 held at the starting position f and the peripheral speed lever 17 are positioned at the neutral position N, the regulating arm 71 swings around the front-rear axial center 73 The neutral holding part A3 which keeps the peripheral speed lever 17 in the neutral position N, and the control arm 71 engage with the peripheral speed lever 17 when the peripheral speed lever 17 is located in the reverse position R, The reverse holding part A4 which regulates the further fluctuation | variation of the lever 17 further is provided.

The pressure oil supply control means B is a hydraulic pump 73 driven by the engine 9, as shown in Figs. 11, 13, 14, and 20, and a cylinder chamber from the hydraulic pump 73. It consists of the flow path 74 to (C), the flow path 75 to the transmission case 10, and the valve 76. As shown in FIG. The valve 76 is formed as a spool valve at one end of the operation shaft 62 of the shift member 61. When the operation shaft 62 is positioned at the neutral position, the valve 76 closes the oil passage 75 to the transmission case 10, and the hydraulic oil from the hydraulic pump 73 passes through the cylinder chamber 74. Supply to (C). On the other hand, when the operation shaft 62 is positioned at the forward position or the backward position, the valve 76 opens the oil passage 75 to discharge the pressure oil in the cylinder chamber C through the oil passage 74. A part of the flow path 74 is formed in the 1st axis T1.

The valve 76 is attached to the spool 76A (corresponding to the valve body) formed at one end of the operation shaft 62, and the valve case is attached to the transmission case 10 and forms a port while inserting the spool 76A. It consists of 76B.

The valve case 76B is composed of a valve case body 76a attached to the transmission case 10 and a port forming sleeve 76b into which the spool 76A is inserted. The sleeve 76b is attached freely in the spool moving direction.

The position of the sleeve 76b is adjusted by adjusting the amount of screwing the sleeve 76b into the valve case body 76a. Moreover, the part which protrudes from the valve case main body 76a of the sleeve 76b is formed with the diameter different from a non-protrusion part in order to make rotation operation easy. 76C is the lock nut of the sleeve 76b, and 76D is a stopper with a bolt that closes the end opening of the sleeve 76b.

In addition, a communication path 76d is formed in the operation shaft 62 to communicate the spool moving space 76S formed between the end face of the spool 76A and the valve case 76B into the transmission case 10. have.

In the above structure, when the operation shaft 62 is positioned at the neutral position, the valve 76 of the pressure oil supply control means B is closed by the spool 76A formed on the operation shaft 62, The hydraulic oil from the pump 73 is supplied to the clutch mechanism 24 via the flow path 74 in the first shaft T1, and the clutch mechanism 24 is opposed to the pressing force of the spring 54 by this pressure oil. It is switched off (power non-delivery). On the other hand, when the operation shaft 62 is positioned at the forward position or the reverse position, the spool 76A is displaced together with the operation shaft 62 and the valve 76 is opened, so that the hydraulic oil from the hydraulic pump 73 Is discharged from the oil passage 75 and is not supplied to the clutch mechanism 24. Therefore, the clutch mechanism 24 is switched to the on state (power transmission state) by the pressing force of the spring 54. That is, there is a relationship as shown in Table 1 between the hydraulic oil supply control means B and the clutch mechanism 24.

In addition, the clutch 53 is mechanically interlocked with the clutch pedal 19 to be turned off against the pressing force by the spring 54 by pressing the clutch pedal 19. The clutch mechanism 24 provides hydraulic removal means for discharging the hydraulic pressure for clutch operation in the clutch 53, that is, the oil passage 74, to the outside (in the transmission case 10) by stepping on the clutch pedal 19. Have In other words, the operation of stepping on the clutch pedal 19 is an operation at engine start-up.

The means for interlocking the clutch 53 to the clutch pedal 19 includes a clutch fork 101 for activating the housing 53A in an off direction through the release bearing 100, as shown in FIG. It is composed of a rotary operation shaft 104 for moving the clutch fork 101 in the off direction through the cam mechanism 103 while interlocking through the rod 102 to step on the pedal 19. .

The hydraulic removal means is composed of a relief valve (EV) as shown in detail in Figures 15 (a), (b), (c). This relief valve EV consists of the hydraulic cylinder Cy and the notch 77 formed in the piston part 55. As shown in FIG. The piston portion 55 is set so that the second operating stroke L2 accompanying the operation of the clutch pedal 19 is larger than the first operating stroke L1 accompanying the hydraulic oil supply to the cylinder chamber C. have. The dimension shape of the notch 77 formed in the piston portion 55 is such that the cylinder chamber C is opened only when the piston portion 55 is operated over the third stroke L3 which is larger than the first operating stroke L1. It is set to communicate with the transmission case 10.

Further, between the operation shaft 62 and the shift gear 60, that is, the shifter 61, the forward melter Fu and the reverse as shown in Figs. 16A, 16B, and 16C are shown. The tumbling Ru is formed. The forward melter Fu keeps the shifter 61 in the forward position while permitting the forward movement of the shifter 61 of the control shaft 62 at the start of the movement from the forward position of the control shaft 62 to the neutral position. In the state, move only the spool 76A to the pressure oil supply position. The reversing cylinder Ru keeps the shifter 61 in the retracted position while allowing the preceding movement of the operating shaft 62 with respect to the shifter 61 at the start of the movement from the retracted position to the neutral position of the operating shaft 62. In the state, move only the spool 76A to the pressure oil supply position.

The means for forming the forward fusion cylinder Fu and the backward fusion cylinder Ru is composed of the fin 110 and the stepped portion 111 as follows. The pin 110 presses and moves the base end of the shifter 61 in accordance with the movement from the backward position to the neutral position and the movement from the neutral position to the forward position of the operation shaft 62. The stepped part 111 presses and moves the base end of the shifter 61 in accordance with the movement from the forward position to the neutral position of the operation shaft 62 and the movement from the neutral position to the reverse position. The distance La between these pins 110 and the stepped portion 111 is set larger than the width Lb of the proximal end of the shifter 61. That is, a forward fusion tube Fu is formed between the shifter 61 positioned at the forward position by pressing the pin 110 and the stepped portion 111, and the shifter 61 positioned at the reverse position by being pressed at the stepped portion 111. And a reverse fusion tube (Ru) is formed between and the fin (110).

As shown in FIG. 11, the sub transmission device 26 rotates the ultra low speed gear gear 78, the low speed gear gear 79, and the high speed gear gear 80 integrally with the input shaft 26a. Interlocking pins 82a for rotatably mounting the ultra low speed manual gear 81 interlocked with the ultra low speed motor gear 78 on the output shaft 26b and interlocking with the ultra low speed manual gear 81. ), A passive body 82 having a low-speed manual gear 82b for interlocking with the low-speed electric gear 79, and a high-speed manual gear unit 82c for interlocking with the high-speed electric gear 80; It is comprised by mounting in the state rotated integrally. When the power of the input shaft 26a is to be transmitted at very low speed to the output shaft 26b, the interlocking pin 82a is operated by the interlocking pin 82a by operating the sub-shift lever 18 in the "overrun" position. The position shifts with the low speed manual gear 81. When the power of the input shaft 26a is to be transmitted at low speed to the output shaft 26b, the low speed manual gear unit 82b is operated by the low speed manual gear unit 82b by operating the passive gear 82 to the "work" position. Meshes with (79) and shifts to the interlocked position. When the power of the input shaft 26a is to be transmitted at high speed to the output shaft 26b, the high speed manual gear unit 82c controls the passive body 82 by the high speed manual gear unit 82c while operating the subshift lever 18 to the "moving" position. It shifts to the position which interlocks with 80 and interlocks.

In FIG. 12, 200 denotes a first main shifting gear that performs three shifts of the main shift with the idler shaft 58 as an input shaft, and 201 denotes an output shaft of the first shifting gear 200 as an input shaft. It is a 2nd main gearshift which performs two main gearshifts, and it is made to perform 6 main gearshifts by combining the shift of the 1st weekly transmission 200 and the shift of the 2nd weekly transmission 201. 202 is a jump clutch which is retrofitted to the output system from the second main transmission 201 and cuts power transmission downward when a load greater than or equal to the set is applied, and 203 is a mother clutch which is linked to the output of the jump clutch 202. As an example, the output of the planting clutch 203 is transmitted to the planting apparatus 2.

Another embodiment

The relief valve EV forming the hydraulic removal means may be configured as shown in FIGS. 21 to 24 instead of FIG. 20.

(1) In the example shown in FIG. 21, the induction valve EV is connected to the flow path 74 as an on-off valve. As the open / close valve is opened, the hydraulic pressure for clutch operation is discharged to the outside from the flow path 74, that is, the cylinder chamber C of the hydraulic cylinder Cy, and as closed, the discharge valve is prevented from being discharged to the outside. In this other embodiment (1), the induction valve EV is reversibly opened in conjunction with the operation of stepping on the clutch pedal 19. In this case, the operation of stepping on the clutch pedal 19 becomes an operation at engine startup. That is, as the operation of stepping on the clutch pedal 19 during engine startup, the pressure in the flow path 74 is reduced, and the starting load of the engine 9 can be reduced by driving the hydraulic pump 73. The startability of the engine 9 can be excellent.

(2) In the above embodiment, the starting load of the engine 9 is reduced by installing the hydraulic removing means. However, as shown in FIG. 22, the hydraulic pump from the engine 9 is accompanied by the operation at the start of the engine. The starting load of the engine 9 may be reduced by providing a means for stopping transmission to 73. In another embodiment (2), in configuring the means, a clutch 150 for turning on and off the transmission from the engine 9 to the hydraulic pump 73 is provided, and the clutch pedal 19 is stepped in accordance with the operation of stepping on the clutch pedal 19. Interlock the clutch 150 to reversibly off. In this case, the operation of stepping on the clutch pedal 19 becomes an operation at engine startup.

(3) In the above embodiment, the operation of stepping on the clutch pedal 19 is shown as the operation at the engine start, but the operation at the engine start may be a start operation of the engine starting motor 151. As a specific example, as shown to FIG. 23, FIG. 24, operation to the motor starting position of the key switch 152 is mentioned. Another embodiment shown in FIG. 23 is to allow the induction valve EV shown in the other embodiment (1) to be reversibly opened by the operation of the key switch 152 to the motor starting position. ) Consists of solenoid valve or electric valve. In another embodiment shown in Fig. 24, the clutch 150 shown in the other embodiment (2) is reversibly turned off by an operation of the key switch 152 to the motor starting position. 150 is electronic or electric.

(4) In the above embodiment, as shown in Fig. 25, the pin 112 is provided in place of the stepped portion 111 for pressing and shifting the shifter 61 to the reverse position, and on both ends of the shifter 61. The cam surface 113 is formed, and the operation axis 62 is rotated to change the position of the axial centers of the pins 110 and 112 with respect to the cam surface 113 so as to space the cam surface 113 from the pins 110 and 112. That is, you may make it adjust the forward melter Fu and the reverse melter Ru.

(5) In the above embodiment, the operating shaft 62 for operating the shifter 61 by the slide in the axial direction is illustrated, but the operating shaft 62 operates the shifter 61 according to the rotation around the shaft center. It may be.

(6) Although the application example to a rice transplanter was shown in the said Example, this invention can be applied to various work machines, such as a combine and a tractor.

Since the present invention is configured as described above, it is possible to simplify the structure and reduce the cost of the clutch mechanism that operates in conjunction with the forward and backward switching operation.

Claims (5)

A gear-type forward and backward switching mechanism 25 that can be switched between the forward state, the neutral state, and the reverse state; And a clutch mechanism (24) for switching the power to the forward / backward switching mechanism (25) to a power transmission state or a power non-transmission state on the basis of the switching operation of the forward / backward switching mechanism (25). In the power transmission device of the working machine which performs the power transmission from the) to the traveling device 22, The clutch mechanism 24, By the pressing force of the spring 54 is switched to the power transmission state, In response to the pressure oil supply to the clutch mechanism 24 by the pressure oil supply control means B, it is switched to the power non-transmission state against the pressing force of the spring 54, and The pressure oil supply control means (B), When the forward and backward switching mechanism 25 is in the neutral state, pressure oil is supplied to the clutch mechanism 24, And a pressurized oil from the clutch mechanism (24) when the forward and backward switching mechanism (25) is in the forward state or the reverse state. 2. The flow path shaft as claimed in claim 1, wherein an input portion of the clutch mechanism (24) is provided with a pressure oil flow path (74) which is linked to the input shaft (10a) of the transmission case (10) and supplied to the clutch mechanism (24). Consisting of T1, The output unit of the clutch mechanism (24) is a power transmission device for a work machine, characterized in that composed of a forward output gear (51) and a reverse output gear (52) rotatably mounted to the flow path shaft (T1). 2. The clutch pedal (19) according to claim 1, wherein the clutch pedal (19) for switching the clutch mechanism (24) to the power non-transmitting state against the pressing force of the spring (54) in accordance with the step of mechanically interlocking with the clutch mechanism (24). Power transmission device for the work machine, characterized in that the installation. 2. The work machine according to claim 1, characterized in that hydraulic removal means (EV) for discharging the clutch operating pressure oil in the clutch mechanism (24) to the outside is provided with the starting operation of the engine (9). Power train. The pressure oil supply control means (B) according to any one of claims 1 to 4, further comprising a valve (76) for supplying and discharging the pressure oil supplied to the clutch mechanism (24), This valve 76 is A valve case 76B incorporated in one end of the operation shaft 62 for changing the position of the shift member 60 of the forward and backward switching mechanism 25, and It is formed in the one end of the operation shaft 62, and when the operating shaft 62 is positioned at the neutral position (N) by the joint operation with the valve case 76B, the hydraulic pressure is supplied to the clutch 53. At the same time, when the operation shaft 62 is positioned at the forward position f or the reverse position R, the work machine is constituted by a valve body 76A for discharging the pressure oil from the clutch 53. Power train.