JPH10138772A - Output stop device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To instantly return an output control means to a stop state and to precisely maintain it by furnishing a return means to return the output control means of a drive device to the output stop state and a stop means to stop the output control means in a precise output stop state by receiving its returning work. SOLUTION: Force to return a speed change lever to a neutral position in a guide groove through a hydraulic control lever 25 and a speed change operating force transmission member 16 by a left side returning lever 36 of an output stop device 17 works on a speed change operating plate. However, the speed change lever is certainly maintained at a totally forward driving position as it is by work of a ratchet mechanism and a spring washer. When a brake pedal is stepped on, a ratchet click is revolved through a brake working shaft, engagement with a ratchet wheel is released, and at that instant, the speed change lever is revolved and returned until it returns to a neutral state by energizing work of the output stop device 17. Consequently, driving output is topped, a drum brake works, and a frame body 2 speedily stops.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output stopping device, and more particularly to a device for accurately returning an output control means of a driving device to an output stopped state and accurately maintaining the output stopped state.

[0002]

2. Description of the Related Art For example, when stopping a vehicle equipped with a hydrostatic transmission (HST) as a driving device, the output control means of the hydrostatic transmission is set apart from a clutch device. Must be accurately returned to the output stopped (neutral) state.

However, the transmission system between the gearshift lever in the driver's seat and the output control means is usually not very precise, so that when the gearshift lever is returned to the output stop position, the output control means does not work. It does not always return to an accurate output stop state, and it is difficult to stop the vehicle body at a target position.

Therefore, the output control means is operatively pulled in the opposite directions by using two tension springs, and the output control means is returned to the output stop state by the balance of the tensile forces of the two tension springs, and The output stop state is maintained.

[0005]

However, in the vicinity of the output stop state of the output control means, since the tension force of the tension spring is relatively weak, the output control means is instantaneously returned to the accurate output stop state. Things have not been done yet.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an output stop device that instantaneously and accurately returns an output control means of a drive device to an output stop state and accurately maintains the output stop state. It is something to offer.

[0007]

In order to solve the above-mentioned problems, an output stop device according to the present invention is provided with a return unit that operates to return an output control unit of a drive unit to an output stop state. And stopping means for receiving the return action and stopping the output control means in an accurate output stop state.

According to this configuration, the output control means is forcibly instantaneously and accurately returned to the output stop state by the interaction between the return means and the stop means, and The output stop state is accurately maintained.

Specifically, the return means includes first and second urging means for urging the output control means to return to the output stop state from opposite directions. This is preferable.

[0010] The first and second urging means may include:
A first lever and a second lever that can swing about a common axis, and an urging member that urges the one end side of these levers to contact the stop means. When the one end side of the swing of the first and second levers comes into contact with the stopping means, the output control means is configured to be held in the output stopped state,
More preferred.

Further, it is more preferable if the position of the stop means is made adjustable in accordance with the output stop state position of the output control means.

It is preferable to use a hydrostatic transmission (HST) as the driving device.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a traveling vehicle body 1 provided with an output stop device according to an embodiment of the present invention, as viewed from obliquely right rear. Here, the traveling vehicle body 1 is of a so-called high clearance type having a minimum ground clearance of about 0.7 m, which is suitable for traveling in paddy fields and fields. The traveling vehicle body 1 is used as a self-propelled work machine by mounting a work machine (not shown) such as a fertilizer, a seeding machine, a transplanter, or a control machine on the machine body 2 as necessary.

In FIG. 1, the traveling vehicle body 1 includes a traveling drive device 3, a traveling speed transmission device 4, a steering device 5,
A braking device 6 and the like are provided.

The traveling drive unit 3 includes a four-stroke internal combustion engine 7 mounted on the body 2 as a traveling drive source. The engine 7 includes a hydrostatic transmission (HST) 8 as a drive unit. And a suitable gear transmission 9 for reduction including a differential device, and a pair of left and right driving rear wheels 10, 10
The drive shafts 11 and 11 are sequentially connected for driving.

The hydrostatic drive transmission 8 has a well-known configuration which enables switching between forward and backward movement of the body 2 and stepless adjustment of the traveling speed. The speed change operation is performed by a speed change lever 13 as a speed change operation member constituting the transmission 4 near the driver's seat 12. The driver, as shown in FIG.
In 2, the traveling vehicle body 1 is driven while operating the steering handle 5a and the shift lever 13 that constitute the steering device 5.

Further, the transmission 4 includes a speed change operation portion 14 including the speed change lever 13, a speed change operation portion 15 that performs a speed change operation in accordance with the operation of the speed change operation portion 14, a speed change operation portion 15, A shift operation force transmitting member 16 (see FIGS. 2 and 5) such as a push-pull control cable, which operatively connects the shift operation section 14 to each other.

Referring to FIGS. 2 and 3, the structure of the shift operation portion 15 will be described. FIG. 2 is an overall schematic perspective view of the speed change operation portion 15, and FIG. 3 is an exploded perspective view of a main part of an output stop device 17 constituting the speed change operation portion 15.

In FIG. 2, the hydrostatic transmission 8 known per se is provided with a variable displacement hydraulic pump 18 and a hydraulic motor 19 integrally.
The HST input pulley 21 drivingly connected to the HST input shaft 20 is drivingly connected to the engine 7. The output shaft 22 of the hydraulic motor 19 is drivingly connected to the drive shafts 11 of the drive rear wheels 10 via the gear transmission 9.

The hydraulic pump 18 has a discharge amount adjusting swash plate 23 as output control means therein, and the discharge amount adjusting swash plate 23 has a discharge amount adjusting swash plate 23 provided outside the hydraulic pump 18. An amount adjusting shaft 24 is operatively connected, and a bent portion 25a of a rectangular hydraulic control lever 25 is fixed to the discharge amount adjusting shaft 24. A swinging one end 25b of the hydraulic control lever 25 is operatively connected to the shift operation unit 14 via the shift operation force transmitting member 16. By operating the shift operation section 14, the shift operation force transmitting member 16 is pushed and pulled, and the hydraulic control lever 25 is swingably operated.

The discharge amount adjusting swash plate 23 of the hydraulic pump 18 is in an output stop state when it is perpendicular to the HST input shaft 20. In the output stop state, the discharge amount of the hydraulic pump 18 is It becomes zero. Further, if the discharge amount adjusting swash plate 23 is tilted in the forward direction (for example, the hydraulic pump 18 side) from the output stop state to be in a forward drive state, the hydraulic motor 19 is driven by the discharge amount adjusting swash plate 23. The main body 2 is driven forward by rotating forward at a rotation speed corresponding to the degree of inclination. Conversely, the discharge amount adjusting swash plate 23 is moved in the reverse direction from the output stop state (for example, the HST input pulley 21).
Side), the hydraulic motor 19 rotates in the reverse direction, and the body 2 is similarly driven backward.

The output stopping device 17 according to the present embodiment includes a swing member 26 operatively connected to the discharge amount adjusting swash plate 23 and the discharge amount adjusting swash plate 23 in the output stopped state. Returning means 27 acting to return
And a fixing member 28 as stop means for receiving the return action of the return means 27 and accurately stopping the discharge amount adjusting swash plate 23 at the output stop state position.

The swing member 26 is, as shown in FIG.
The body 2 has a rectangular plate shape extending in the front-rear direction, and its rear base end 26a is pivoted on a pivot shaft 29 having an axis X extending in the vertical direction.
The b side is connected to the other end 25c of the hydraulic control lever 25 via a tie rod 30 so as to be rotatable in a horizontal plane.

The pivot shaft 29 projects upward from the front side of the rectangular plate-shaped fixing member 28 extending in the front-rear direction. The fixing member 28 has the same lateral width as the swinging member 26, and the rear side thereof is
Two bolts 32, 32 and nut 33,
33. The fixed base 31 is fixed to a gear case 34 of the gear transmission 9 as a fixed part.

It is to be noted that the fixing member 28 is provided with the pivot shaft 29 in accordance with the output stop state of the discharge amount adjusting swash plate 23.
In order to be able to adjust the position of the front bolt 32 to the left and right, a long hole 35 extending in the left-right direction in an arc centered on the rear bolt 32 for receiving the front bolt 32 is provided.

The left return lever 3 which is symmetrical to the left return lever 3 and is superimposed on the swing member 26,
6 and the right return lever 37 are pivotally held in a scissor-like manner. These return levers 36 and 37 are connected to the discharge amount adjusting swash plate 2.
3 are first and second urging means for urging the third members 3 to return to the output stop state from opposite directions. The rear ends 36a and 37a are used as discharge amount adjusting swash plate returning urging members. The front end portions 36b, 37b of the discharge amount adjusting swash plate return spring 38 are connected to each other by the pulling coil spring 38 so as to attract each other. They are strongly urged toward each other.

On the front end portion 36b side of the left return lever 36, a right swing member contact portion 39 and a right fixed member contact portion 40, which contact the swing member 26 and the fixed member 28 from the right side, respectively. Are formed respectively. Also,
On the front end portion 37b side of the right return lever 37, a left swing member contact portion 41 and a left fixed member contact portion 42 that contact the swing member 26 and the fixed member 28 from the left side, respectively. Is formed. The right and left fixing member contact portions 42 and 40 contact both left and right edges of the fixing member 28, and at the same time, the left and right swing member contact portions 4 and 40.
1 and 39 abut against an upwardly projecting shaft 43 formed in the center of the front side of the swing member 26 from both left and right sides.
The swing member 26 is pivotally attached to the fixed member 28 so as to maintain the discharge amount adjusting swash plate 23 in the output stopped state.

The above-described shift operation portion 1 configured as described above
5 works as follows.

When the shift lever 13 is operated back and forth,
The shift operation force transmission member 16 is pushed and pulled, and the discharge amount adjusting swash plate is opposed to the urging forces of the left and right return levers 36 and 37 via the hydraulic control lever 25 and the discharge amount adjusting shaft 24. 23 HST input shaft 20
The inclination direction and the inclination angle with respect to are adjusted freely. Thereby, the rotation direction and output of the hydraulic motor 19 constituting the hydrostatic drive transmission 8 are adjusted, and switching between the forward traveling and the reverse traveling of the body 2 and the stepless adjustment of the forward / backward traveling speed are performed. Will be

The discharge amount adjusting swash plate 23 is brought into the output stopped (neutral) state by the left and right return levers 36 and 37 via the hydraulic control lever 25, the tie rod 30, and the swing member 26. Since the return force is constantly applied, if the shift lever 13 is shifted to the neutral position, the discharge amount adjusting swash plate 23 returns to the output stop state instantaneously. Moreover, the swing member 26 is
Since the left and right return levers 36 and 37 and the discharge amount adjusting swash plate returning spring 38 are strongly fixed to the fixing member 28 from the left and right directions, the discharge amount adjusting swash plate 23 can be accurately adjusted. Then, the output is stopped. Therefore, the driver can always and quickly stop the output from the hydrostatic transmission 8.

Next, with reference to FIGS. 4 to 6, the configuration of the shift operation section 14 of the transmission 4 and the braking device 6 will be described. 4 is a schematic perspective view showing the vicinity of the driver's seat 12 of the traveling vehicle body 1, FIG. 5 is a left side view showing the inside of the speed change operation unit 14 in FIG. 4, and FIG.
FIG. 3 is a partially cutaway explanatory view of the inside of the speed change operation unit viewed from the rear of the machine body.

In the illustrated example, the braking device 6 is operatively connected to the shift action portion 15 via the shift operating portion 14 and the shift operating force transmitting member 16, and is interlocked with the braking operation of the braking device 6. As a result, the shift operation unit 15 automatically stops the output of the traveling driving force.

That is, when operating the braking device 6, the output of the hydrostatic transmission 8 must be stopped. However, it is troublesome to manually stop the output of the hydrostatic transmission 8 manually when operating the braking device 6. Further, when the machine body 2 is suddenly stopped, the output stop operation of the hydrostatic drive transmission 8 may not be performed in time, and the mechanical structure may be overloaded. Therefore, in order to resolve these inconveniences,
At the time of braking of the forward drive, the traveling drive output is automatically and reliably stopped in conjunction with the braking operation.

In FIGS. 5 and 6, the speed change lever 13 as the speed change operation member constituting the speed change operation portion 14 is moved forward and backward so that the upper end portion 13a can swing in the left and right direction of the machine body 2. The lower end 13b is fixed to the speed change operation plate 45 by a pin 44 extending in the direction. The transmission lever 13 is provided with a tension spring 4.
6 is urged by a suitable urging means such as 6 so as to always contact the right edge of the shift lever guide groove 48 provided in the shift operation section cover 47.

The speed change operation plate 45 is inserted into a ratchet wheel shaft 49 extending in the left-right direction of the machine body 2 and rotatable around its axis YY. The shift operation plate 45 has a front end portion 51 a of the shift operation force transmitting member 16.
Are connected, and a force for returning the shift lever 13 to the neutral position is constantly applied by the operation of the output stop device 17.

A ratchet wheel 53 is fixed on the ratchet wheel shaft 49 as shown in FIG. The ratchet pawl 54 is engaged. The ratchet mechanism including the ratchet pawl 54 and the ratchet wheel 53 allows only the rotation of the ratchet wheel shaft 49 in the counterclockwise direction as viewed in FIG. 5, and functions as a forward output state holding unit.

The ratchet pawl 54 is connected to the braking device 6
Is operatively connected to a brake pedal 55 as a brake operation member, and the engagement state with the ratchet wheel 53 is released in conjunction with the depressing braking operation of the brake pedal 55.

More specifically, as shown in FIG. 4, a left end portion 57a of a brake operation shaft 57 extending horizontally in the left-right direction of the body 2 and supporting an arm 56 of the brake pedal 55.
Is extended to the vicinity of the ratchet wheel 53. The brake operation shaft 57 is connected to the brake pedal 5.
5 is constantly urged by a suitable urging means so as to maintain the non-braking state. Then, the ratchet pawl 5 is attached to the left end portion 57a of the brake operation shaft 57 so that the ratchet wheel 53 is automatically engaged with the ratchet wheel 53 by the rotational urging force of the brake operation shaft 57.
4 is fixed.

As shown in FIG.
A brake operation lever 58 is fixed to 7. The brake operation lever 58 is operatively connected to an internal expansion type drum brake 59 as braking means for the traveling vehicle body 1. Then, when the brake pedal 55 is depressed, the internal expansion type drum brake 59 is operated, and the rear wheel drive shaft 11 is braked via the braking force transmission shaft 60.

A manual hook 61 is rotatably attached to the body 2 as braking state holding means for holding the brake pedal 55 in a braking state. The hook 61 is manually engaged with a locking bar 62 extending rightward and horizontally from the brake pedal 55. The hook 61 functions as a parking brake by holding the brake pedal 55 depressed as it is and holding the internal expansion type drum brake 59 in a braking state.

The speed change operation plate 45 is rotatable with respect to the ratchet wheel shaft 49, and the speed change operation plate 45 is inserted through the ratchet wheel shaft 49 as shown in FIG. With the pressing force of the spring washer 50, the spring washer 50 is sandwiched between the lining brake plates 62, 62 from both sides thereof, and imparts a predetermined amount of rotation resistance (operation resistance) to the ratchet wheel shaft 49. This is to enable the operation lever 13 to be manually operated backward regardless of the existence of the ratchet mechanisms 53 and 54.

The magnitude of the rotation resistance is set to be larger than the return urging force applied to the discharge amount adjusting swash plate 23 by the left and right return levers 36 and 37 to return to the output stop state. Therefore, even if the driver releases his / her hand from the shift lever 13, the forward drive shift position of the shift lever 13 is maintained as it is, and the discharge amount adjusting swash plate 23 is maintained.
Is held in the forward drive output state. That is, the spring washer 50, together with the ratchet mechanisms 53, 54,
It also functions as forward output state holding means.

As shown in FIG. 5, the speed change operation force transmitting member 16 for pushing and pulling the swinging one end 25b of the hydraulic control lever 25 in response to the operation of the speed change lever 13 is provided on the speed change operation plate 45. Are connected to each other. The shift operation force transmitting member 16 is an outer tube that slidably encloses two front and rear end rods 511 and 512 and an inner wire (not shown) connecting the end rods 511 and 512 to each other in the longitudinal direction. 52 and is well known per se. As the inner wire, use is made of a steel wire which is rich in elasticity so as not to cause a small bending and has high tensile strength and compressive strength in the longitudinal direction. An appropriate lubricant is interposed between the inner wire and the outer tube 52 so that the inner wire can slide smoothly.

The front end 52a of the outer tube 52
As shown in FIG. 5, at a position obliquely below and in front of the speed change operation plate 45, the
Being pivoted to. And, the outer tube 52
Is gently curved rearward at the position in front of the driver's seat 12 and extended rearward of the body 2, and the rear end 52
b is fixed to the machine body 2 in front of the hydrostatic transmission 8 as shown in FIG. A front end portion 51a of the front end rod 511 protruding from the front end portion 52a of the outer tube 52 is rotatably connected to the speed change operation plate 45 and extends rearward from the rear end portion 52b of the outer tube 52. The rear end portion 51b of the rear end rod 512 protruding from the hydraulic control lever 25 is pivotally fixed to the swinging end portion 25b of the hydraulic control lever 25.

The speed change operation unit 1 configured as described above
4 and the braking device 6 operate as follows.

When the output amount adjusting swash plate 23 of the hydrostatic drive transmission 8 is in the output stop state by the operation of the output stop device 17, the shift lever 13 is
Is located at a neutral position (the position of the transmission lever 13 shown by a solid line in FIGS. 4 to 6) which is an intermediate step portion of the transmission lever guide groove 48.

Then, from the neutral position, the shift lever 1
When the gear 3 is moved forward of the body 2 along the shift lever guide groove 48, the shift operation plate 45 is rotated counterclockwise as viewed in FIG. Rotating in the rotation direction, the front end rod 511 of the transmission operation force transmission member 16 is pulled out of the outer tube 52. As a result, the hydraulic control lever 25 swings clockwise as viewed in FIG. 2, the discharge amount adjusting swash plate 23 is tilted in a forward drive state, and the hydraulic motor 19 rotates forward to rotate the machine body 2. Moves forward.

At this time, the left-hand return lever 36 of the output stop device 17 is attached to the speed change operation plate 45 by the left return lever 36.
Through the hydraulic control lever 25 and the shift operation force transmitting member 16, a force acting to return the shift lever 13 to the neutral position in the shift lever guide groove 48 is applied. However, the ratchet mechanisms 53, 54
And the action of the spring washer 50, the shift lever 13
Is reliably maintained at the forward drive shift position.

When stopping the forward movement of the body 2,
The driver may depress the brake pedal 55. Then, as shown in FIG. 4, the ratchet pawl 54 rotates via the brake operation shaft 57 and the engagement with the ratchet wheel 53 is released. At that moment, the shift operation plate 45 is rotated back in the clockwise direction as viewed in FIG. 5 until the shift lever 13 returns to the neutral position by the urging action of the output stop device 17. As a result, at the same time as the forward drive output from the hydrostatic drive transmission 8 is stopped, the internal expansion type drum brake 59 is actuated, and the machine body 2 is stopped quickly without difficulty.

On the other hand, when the shift lever 13 is moved from the neutral position to the rear of the machine body 2 along the shift lever guide groove 48, the ratchet pawl 54 always engages with the ratchet wheel 53. The ratchet wheel shaft 49 does not rotate, but the spring washer 5
By the action of 0, the speed change operation plate 45 rotates clockwise as viewed in FIG. 5 independently of the ratchet wheel shaft 49, and the front end rod 511 of the speed change operation force transmitting member 16 It is pushed into the rear of the body 2 in the outer tube 52. As a result, the hydraulic control lever 25 swings counterclockwise as viewed in FIG. 2, the discharge amount adjusting swash plate 23 is tilted in the reverse drive state, and the hydraulic motor 19 rotates in the reverse direction to cause the machine body 2 to rotate. Moves backwards.

At this time, the right-hand return lever 37 of the output stop device 17 is attached to the speed change operation plate 45.
A force for returning the shift lever 13 to the neutral position in the shift lever guide groove 48 always acts through the hydraulic control lever 25 and the shift operation force transmitting member 16. In the case of reverse drive, the ratchet mechanisms 53 and 54 do not work to hold the speed change lever 13 at the reverse drive shift position. Therefore, unlike the case of the forward drive, the driver must keep holding the shift lever 13 at the reverse drive shift position. However, in the traveling vehicle body 1 as shown in the figure, since the frequency of the reverse drive is low and the reverse travel time is short, the problem is small.

When stopping the reverse movement of the body 2,
The driver may release his hand from the shift lever 13 held at the reverse drive shift position and depress the brake pedal 55.

Needless to say, the forward speed can be freely increased or decreased by the above-described configuration.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a traveling vehicle body provided with an output stop device according to an embodiment of the present invention, as viewed from obliquely right rear.

FIG. 2 is an overall schematic perspective view of a shift operation portion including an output stop device according to an embodiment of the present invention.

FIG. 3 is an exploded perspective view of a main part of the output stopping device in FIG. 2;

FIG. 4 is a schematic perspective view showing the vicinity of a driver seat of the traveling vehicle body shown in FIG.

FIG. 5 is a left side view showing the inside of the speed change operation unit in FIG. 4;

FIG. 6 is a partially cutaway explanatory view of the speed change operation unit of FIG. 5 as viewed from the rear of the machine body.

[Explanation of symbols]

 Reference Signs List 8 drive device (hydrostatic drive transmission (HST)) 23 output control means 27 return means 28 stopping means 36 first lever (biasing means) 36b swing end 37 second lever (biasing means) 37b swing Moving end 38 Biasing member X axis

Claims (5)

[Claims] 1. An output control means (23) of a drive device (8).
Return means (27) acting to return the output control unit to the output stop state, and stop means (28) receiving the return operation of the return means (27) and stopping the output control means (23) to the correct output stop state. ), And an output stopping device comprising: 2. The first and second biasing means (36) for biasing the output control means (23) to return the output control means (23) to the output stop state from opposite directions. The output stopping device according to claim 1, further comprising: (37). 3. The first and second biasing means include first and second levers (36) and (37) swingable about an axis (X) common to each other, and these levers (3
6), an urging member (38) for urging the one end (36b), (37b) side of (37) to abut against the stopping means (28). The swinging one end (36) of the first and second levers (36), (37)
The output stop device according to claim 2, wherein the output control means (23) is kept in the output stop state when the b) and (37b) sides come into contact with the stop means (28). . 4. The output stopping device according to claim 1, wherein the position of said stopping means (28) can be adjusted in accordance with the output stopping state position of said output control means (23). 5. The output stop device according to claim 1, wherein the drive device (8) is a hydrostatic transmission (HST).