JP2833007B2 - Power transmission system for powered vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a traveling transmission for a powered vehicle.

[Background Art and Problems to be Solved by the Invention] In a so-called four-wheel drive type tractor, for example, when one rear wheel is braked to make a sharp turn, the ground running speed of the other rear wheel is set to Although the speed is almost doubled by the operation of the differential mechanism for the wheels, the front wheels are driven by the same drive system as when traveling straight, so they cannot follow the speed after the rear wheels change. The turning radius becomes larger than when the front wheels are not driven due to front wheel resistance. So conventionally,
In order to make the machine easy for beginners to handle, a speed increasing mechanism that can increase the speed of the front wheels to twice the speed during this sharp turn or a switching mechanism that can stop driving of the front wheels has been folded. However, in the tractor of this embodiment, the switching operation of these mechanisms must be performed at all times at the start of turning and after the turning, which is troublesome and troublesome. In addition, when operating this conventional mechanism, the front wheels rotate at twice the speed in the case of runaway due to so-called "dashing" in a rotary tilling operation performed at a low speed or in a case of climbing or descending at a lower speed. Therefore, there are inherent dangers of danger of contact with other objects at the time of maneuvering and runaway due to zero support force of the front wheel on the slope due to the break of the precursor. In other words, it is a power vehicle that is easy for beginners to use in a field with ordinary flat and uneven soil, but when driving on poor conditions, hard soil or hill slope, conversely, skill is required And

[Means for Solving the Problems] The present invention is to solve such a problem of the conventional device, and has taken the following technical means. That is, one of the pair of left and right front and rear wheels 1 and 2 is used as a steering wheel, and a transmission transmission case 4 is provided between the front and rear wheels 1 and 2 and includes a transmission mechanism 3 for the front and rear wheels 1 and 2. A power transmission of a powered vehicle provided with a front-rear steering wheel drive shaft 6 that is transmitted from the speed change transmission mechanism 3 to one end side of the vehicle and that transmits power to a steering wheel differential mechanism 5 located between the left and right steering wheels. In the device, an automatic clutch 7 is disposed between the speed change transmission mechanism 3 and the steered wheel drive shaft 6, and the drive transmission rotational speed to the steered wheels is either forward or backward when the steered wheels are turned. Also in this case, an automatic clutch 7 is provided which automatically cuts off the transmission to the steering wheel drive shaft 6 when the speed of the aircraft falls below a certain range with respect to the ground running speed. Restriction mechanism 8 for restricting clutch 7 to the connected state
The driving transmission device for a powered vehicle is characterized by having the following.

[Operation and Effect of the Invention] The speed change transmission mechanism 3 in the speed change transmission case 4 includes left and right rear wheels.
In addition to transmitting the driving force to the front wheels 2 and 2, the driving force is also transmitted to the left and right front wheels 1 and 1 via the automatic clutch 7, the steering wheel drive shaft 6 and the steering wheel differential mechanism 5.

For example, when the rear wheel 2 on one side is braked to make a sharp turn, when the ground running speed of the rear wheel 2 on the other side becomes almost twice the speed by the action of the rear wheel differential mechanism, the automatic clutch 7 automatically drives the steered wheels. The transmission to shaft 6 is cut off, that is, the front wheels that are the steered wheels
Since 1,1 is in a rolling state in which it is not driven and becomes a two-wheel drive state by rear wheels 2,2, the front wheel 1, which is a steered wheel, is more freely rolled and rotated according to the traveling speed of the aircraft than in the case of driving four wheels. Because of the sliding, the rotational resistance of the steered wheels does not increase and the turning radius does not increase. When the ground running speed of the rear wheels 2, 2 is restored to the normal speed after turning, the automatic clutch 7 automatically drives the steering wheel drive shaft 6, that is, enters the four-wheel drive state.

Further, since the automatic clutch 7 is provided with the regulating mechanism 8 which does not perform the clutch “disengagement”, the state in which the clutch “disengagement” cannot be automatically performed from the state in which the clutch “disengagement” can be automatically performed by the operation of the regulating mechanism 8. Can be changed optimally according to the condition of the field, and a simple and easy operation state can be maintained.

By such an operation, when two-wheel drive is required, when two-wheel drive is required, the mutual switching is automatically performed, so that there is no need to perform the switching operation each time as described above, and therefore, It is intended to make turning and running work appropriate and easy.

[Embodiment] As shown in FIG. 4, a motor 13 having an output shaft 12 projecting rearward is mounted on a frame 11 forming a front portion of the vehicle body. A main clutch transmitted from the output shaft 12 is provided between the frame 11 and the rear end.
A front end portion of a front transmission case 16 in which a transmission mechanism 15 transmitted from the main clutch 14 is housed is mounted.
The rear end of the front transmission case 16 is provided with the transmission mechanism.
A front end of a speed change transmission case 4 having a speed change transmission mechanism 3 for shifting the transmission from the transmission 15 is mounted, and a rear wheel differential transmitted from the speed change transmission mechanism 3 is attached to a rear end of the speed change transmission case 4. A rear transmission case 18 in which a mechanism 17 is mounted is attached. Also, on the upper side of the rear transmission case 18,
A pair of left and right lift arms 19, 19 projecting rearward and upward
And a cylinder case 20 in which a hydraulic cylinder (not shown) serving as an actuator of the lift arms 19, 19 is provided.

On the lower side of the frame 11, a support 22 having a pin 21 in the front-rear direction, which is a center pivot, is provided.
22, an input shaft 23 protruding rearward, a steering wheel differential mechanism 5, which is the front wheel 1, which is driven by the input shaft 23, and a left and right transmitted from the steering wheel differential mechanism 5 to the left and right. The front axle case 25 having the transmission shafts 24, 24 mounted therein is swingably supported. And this time axle case 25
Front wheels 1, 1 which are steering wheels interposed in steering transmission mechanisms 26, 26 are attached to left and right end portions of the vehicle, respectively. Further, on both left and right sides of the rear transmission case 18, the rear wheel differential mechanism is provided.
Axle case after installing the transmission mechanism transmitted from 17
The rear wheels 2, 2 which are non-steered wheels are mounted on the protruding ends of the rear axle case 27, respectively.

As shown in FIG. 1, a bearing 28 provided at the lower part of the front wall of the speed change transmission case 4 supports a front end of a terminal transmission shaft 29 of the speed change transmission mechanism 3. The cylindrical part having a spline 30 at the front of the inner peripheral surface of the large diameter part
The boss portion 33 of the exterior body of the automatic clutch 7 including the upright wall portion 31 at the rear end of the cylindrical portion 31 and the boss portion 33 having a small diameter projecting rearward from the upright wall portion 32 is spline-engaged. doing.

A small-diameter portion provided at the rear end of the driven shaft 35 is rotatably supported on an axial bearing 34 provided at the front end of the transmission shaft 29. Around the rear part of the driven shaft 35, a trapezoidal shape and a driven clutch
The boss portion of the driven body 37 having splines 36, 36 ... is spline-engaged, and a bearing 38 which is slidable and rotatable with respect to the driven shaft 35 around the driven shaft 35 in front of the driven body 37. Are provided on the outer peripheral surface of the bearing 38. The driving clutch small pawls 36a, 36 meshing with the driven clutch small pawls 36, 36.
a ... and both clutch small claws 36, 36a
A boss portion of a sliding body 40 having a larger trapezoidal driven cam 39, 39 ... (also shown in FIG. 2) is fixed, and further provided on the inner periphery of the large-diameter cylindrical portion 31. Spline 30
The driving cams 39a, 39a ... meshing with the driven cams 39, 39 ... on the rear surface.
The large-diameter outer portion of the ring-shaped driving body 41 having the shape is integrally fixed by a retaining ring. The vertical wall of the cylindrical portion 31
32 between the sliding member 40 and the flange portion of the sliding member 40.
42 that urges the spring away from the standing wall portion 32
Is installed.

A bearing 44 for supporting the outer peripheral surface of the boss 33 of the cylindrical portion 31 is provided on the flange 43 of the rear wall of the front transmission case 16.
A case 45 of the automatic clutch 7 having an insertion hole for the sliding body 40 in the front wall portion and covering the outer periphery of the cylindrical portion 31 is attached to the front surface of the flange portion 43. The insertion hole is provided with a seal member 46 for imparting a certain resistance to the rotation of the sliding member 40.

FIG. 1 shows a case 45 having a bearing 47 for supporting a front portion of the driven shaft 35 on a front wall portion of the case 45, and a front side of the sliding body 40 around the driven shaft 35, A thrust bearing 49 is provided, and a support shaft 50 of the regulating mechanism 8 rotatably supported by the case 45 is provided above the front side of the thrust bearing 49. The thrust bearing 49 is mounted on the support shaft 50. An arm 51 for restricting and pressing the sliding body 40 so as not to slide in the front-rear direction is mounted.

Further, in the vicinity of the terminal transmission shaft 29 of the speed change transmission mechanism 3, an actuator capable of detecting the rotation speed of the terminal transmission shaft 29 below a certain range and moving the arm 51 of the regulation mechanism 8 backward is moved. Speed sensor 9 is provided. Further, the front end of the driven shaft 35 and the protruding portion of the input shaft 23 on the front axle case 25 side are connected by a steering wheel drive shaft 6 to the front wheel 1 having universal shaft joints 55 at both front and rear ends. .

Next, the operation will be described. The main clutch 14 transmitted to the output shaft 12 of the prime mover 13 is connected to the left and right rear wheels 2, 2 via a transmission mechanism 15, a speed change transmission mechanism 3, a rear wheel differential mechanism 17, and a transmission mechanism in a transmission case 27, 27. To be transmitted.

On the other hand, when the terminal transmission shaft 29 of the speed change transmission mechanism 3 is driven to rotate in a downward direction before the shaft shown by the arrow “a” in FIG. 2, the spline 30 of the cylindrical portion 31 engaged with the transmission shaft 29, the spline
The driving cams 39a, 39a ... of the driving body 41 engaged with 30 are also driven to rotate in the direction of the arrow `` b '' on the front side, and a plurality of driven cams 39, 39 provided on the front surface of the flange-like portion of the sliding body 40. .. drive cam 39a
Is pressed and moved in the direction of the arrow "C" by the cam slope of. Since the drive clutch small claws 36a, 36a on the front surface of the flange-shaped portion of the sliding body 40 are also integral, they move in the direction of arrow "C" and drive-transmit the driven body 37 via the driven clutch small claws 36 meshing with each other. Since the boss portion of the driven body 37 and the rear part of the driven shaft 35 are in spline engagement, the driving force is transmitted from the driven body 37 via the driven shaft 35, the universal shaft joint 55, the steering wheel drive shaft 6, and the universal joint 55. The power is transmitted to the front wheel input shaft 23 and transmitted from the input shaft 23 to the left and right front wheels 1, 1 via the steering wheel differential mechanism 5, the transmission shafts 24, 24 and the steering transmission mechanisms 26, 26.

As described above, when the front wheels 1, 1, which are the steered wheels to be stopped during non-traveling, are driven by the terminal transmission shaft 29 of the transmission 3, the front wheels 1, 1 move in the direction of arrow “B” in one direction. With respect to the drive surface of the drive cams 39a, 39a,... Of the drive body 41 that rotates integrally with the transmission shaft 29, the drive body rotates with the resistance of the seal body 46 attached to the case 45 with a delay of the resistance. Since the driven surfaces of the driven cams 39, 39 ... of the sliding body 40 are in contact with each other, the thrust of the cam slope on the driving side opposes the spring 42 and slides and presses the sliding body 40 in the direction indicated by the arrow C. The driving clutch small claws 36a, 36a ... provided on the rear flange portion of the sliding body 40 and the driven clutch small claws 36, 36 ...
And the driving force is transmitted from the sliding body 40 to the driven body 37.

Next, when the vehicle is driven by the four-wheel drive, for example, when the tractor, which is a powered vehicle, is turning, the one-side rear wheel 2 serving as the turning inner wheel is braked, and the rear-side differential mechanism 17 is actuated. When the ground running speed of the wheel 2 becomes double speed, the ground speed of the aircraft at the time of turning of the tractor moves at almost twice the speed, and if the front wheels 1, 1 which are steering wheels are simply rolling wheels, the front wheels 1
It is known from experience that the vehicle turns around twice as fast.

At this time, if the front wheels 1, 1 which are the steered wheels are connected at a fixed speed ratio by the terminal transmission shaft 29 of the speed change transmission mechanism 3, the ground traveling speed of the aircraft attempting to turn at twice the speed will be reduced. On the other hand, the peripheral speed of the front wheels 1, 1 does not change, so the front of the fuselage (front wheels)
Becomes a resistance and the turning radius tends to increase.

The automatic clutch 7 in the figure automatically disconnects the power transmission by following the change in the peripheral speed of the front wheels 1 and 1, which are the steered wheels at the time of turning, and sets the drive transmission steered wheels as rolling steered wheels. By following the ground traveling speed, the above-described drawback caused at the time of turning is eliminated, and will be described in detail below.

That is, when the forward traveling speed of the rear part of the aircraft increased by about twice due to the rear inner wheel braking during turning, the front wheels 1, 1 which were the steering wheels provided at the front part of the aircraft were naturally pushed by the rear wheels. It is turned faster than the drive rotation at the start of turning from the initial straight running. The force to turn the front wheel 1, which is the steered wheel, quickly,
Transmission connected front wheels 1, transmission shaft 24, steering wheel differential mechanism
5, via the input shaft 23 and the steered wheel drive shaft 6, reach the driven shaft 35 in the automatic clutch 7, and spline engage the driven body 37 around the rear part of the driven shaft 35 at the time of turning from the initial straight running. Faster than drive rotation (indicated by dashed arrow "d" in FIG. 2)
I will turn it. In addition, at the time of turning from the initial straight traveling of the four-wheel drive to the start of turning, the driven member 37 is driven by the sliding member via the driven clutch small pawls 36, 36 ... provided on the front surface of the flange portion.
Drive clutch small pawl provided on the rear surface of the 40 rear end flange
36a, 36a ...
As shown in FIG. 2, the members up to the sliding body 40 are rotated by the front wheels 1 which are the steered wheels while meshing with the rotation of the arrow "b" as shown in FIG.

As described above, in order to follow the high vehicle speed of the body pushed by the rear wheels 2, the front wheels 1, 1 as the steered wheels are driven by the reverse transmission from the front wheels 1, 1, which are the steered wheels that are turned quickly, to cause the arrow “d”. As shown in the figure, the driven cams 39, 39,.
, And the driven surface of the driven cam 39 precedes the driving body 41
A gap is generated between the driving surfaces of the driving cams 39a, 39a,... And the thrust by the cam slope disappears, and the pressing force of the spring 4 causes the flange-like portion of the sliding body 40 to move forward in the direction of arrow "e". When pressed, it moves in the axial direction, and the driven clutch small claws 36a, 36a,
36a will be disengaged as shown in FIG. This means that when the peripheral speed of the front wheel 1, which is the driving wheel, which is being transmitted, is pushed by the rear wheel 2 or due to another cause, the front wheels 1, 1 which are the steering wheels receive the driving transmission when the body moves faster. It rotates freely on the speed increasing side as a free state refused by itself.

Further, when the ground running speed of the rear wheels 2, 2 is restored to the normal speed after the turn, the running side of the aircraft returns to the original position, and the reverse transmission from the front wheels 1, 1 is eliminated. , 36a mesh with each other, and the front wheels 1, 1 enter a drive transmission state.

In the automatic disengagement configuration of the automatic clutch 7 of the present invention, when the rear wheel 2 which is the rear part of the fuselage is operated for a moment by operating the sudden brake while traveling down a steep slope, the automatic disengagement configuration of the automatic clutch 7 is activated. Since the drive transmission to the front wheels 1 is cut off and the aircraft may drop in the rear wheels 2 in a slip state with respect to the ground, in such a case, the arm 51 of the regulating mechanism 8 is rotated backward via an actuator (not shown) in advance. Sliding body
If 40 is pushed backward, safety is assured.

Usually, on such a steep uneven surface, the driver feels danger and travels very slowly, so that danger hardly occurs. However, when the driver travels very slowly due to danger, as another safety mechanism, the speed sensor 9 is connected to the terminal transmission shaft.
When the rotation speed below a certain range of 29, that is, the low traveling speed below a certain range is detected, the arm 51 of the regulating mechanism 8 is rotated backward through an actuator (not shown) to press and move the sliding body 40 backward. That is, the drive clutch small pawls 36a, 36a provided on the rear surface of the flange-shaped portion of the sliding body 40 and the driven body 37
It is possible to prevent the engagement with the driven clutch small pawls 36, 36 ... from being disengaged in any state, that is, the driving transmission state of the front wheels 1, 1 as the steered wheels is maintained due to the inability of the sliding body 40 to slide forward. Is done. When the regulating mechanism 8 is automatically or manually operated on a steep slope or the like, the front and rear wheels 1 and 2 are both driven and ground, so that even if one of the front and rear wheels 1 and 2 floats, the other wheel is inclined downward. The steering can be heavy, but it can be run safely, while it is possible to run while preventing slippage.

Although the above is an embodiment in which the speed sensor 9 is provided, the regulation mechanism 8 is detected by detecting the inclination of the vehicle body over a certain range or more in correspondence with uphill running, left / right running with respect to the traveling direction, or the like. It is also possible to provide a tilt sensor for restricting operation, or a position sensor for restricting operation of the restricting mechanism 8 by detecting a set shift position of the shift lever 56 for shifting the transmission mechanism 3.

In the illustrated example, the automatic disengagement of the automatic clutch 7 has been described only when the powered vehicle is moving forward. However, when the vehicle is traveling while steering the front wheel 1 as the steered wheel while braking the rear wheel 2 on one side at the time of reversing, the power drive is also performed. When the connected steered wheels make a large turn due to resistance, the rotation direction is reversed in the direction indicated by the arrow "d" by the automatic clutch 7, but the driven clutch small pawl 36 of the driven body 37, 36 rotates quickly,
Drive clutch small pawls 36a, 36a provided on the rear surface of the flange-shaped part of 0
Is disengaged, the automatic clutch 7 is disengaged as in the case of forward movement, and steering turning is easy.

FIG. 5 shows two foot pedals 57, 57 which can respectively brake the left and right rear wheels 2, 2 by a stepping operation. The petal 57 on one side is connected to the petal 57 on the other side by a turning operation. The connecting member 58 is pivotally connected, and near the connecting member 58, the connecting member 58 is connected.
Is provided with a sensor 59 for detecting the connection between the two and the rear wheels 2, 2 when the petals 57 are simultaneously stepped on by the connecting tool 58.
Is braked, and the front wheels 1,1 are also braked via the transmission systems from the rear wheels 2,2 to the front wheels 1,1, so that the braking force of the vehicle body is improved.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a side sectional view, FIGS. 2 and 3 are partial side sectional views, FIG. 4 is an overall side view, and FIG. It is a top view of a part. In the figure, reference numeral 1 denotes a front wheel for steering, 2 denotes a rear wheel, 3 denotes a speed change transmission mechanism, 4 denotes a speed change transmission case, 5 denotes a steering wheel differential mechanism, 6
Is a steering wheel drive shaft, 7 is an automatic clutch, 8 is a regulating mechanism, 9
Indicates a speed sensor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60K 23/08 B60K 17/34-17/358

Claims (1)

(57) [Claims] 1. One of a pair of left and right front and rear wheels 1 and 2 is used as a steering wheel, and is located between the front and rear wheels 1 and 2.
One end of a speed change transmission case 4 having a speed change transmission mechanism 3 mounted therein, which is transmitted from the speed change transmission mechanism 3 to the power transmission direction to the steering wheel differential mechanism 5 located between the left and right steering wheels in the front-rear direction. In a traveling transmission for a powered vehicle provided with a steering wheel drive shaft 6, an automatic clutch 7 is disposed between the speed change transmission mechanism 3 and the steering wheel drive shaft 6, and the rotational speed of the drive transmission to the steered wheels is reduced. An automatic clutch for automatically turning off transmission to the steering wheel drive shaft 6 by lowering the vehicle to a ground speed or less than a certain range when the vehicle steers and turns when traveling forward or backward. 7 and the automatic clutch 7
A driving mechanism for a power vehicle, comprising a regulating mechanism 8 for regulating the automatic clutch 7 to a connected state.