KR101006186B1 - Driving mode changeover apparatus integrated transmission into steering device and electric working device using the same - Google Patents

Abstract

PURPOSE: A driving mode conversion device and an agricultural electric working machine using the same are provided to remove the fear of malfunction and to secure stability using only mechanical elements. CONSTITUTION: A driving mode conversion device comprises a steering conversion unit and speed conversion unit which are combined with the bottom of an operation lever and are equipped with a key rod capable of enabling forward and backward movement according to the manipulation of the operation lever. The steering conversion unit comprises: a first steering propeller shaft revolving the drive shaft of a steering wheel; a second steering propeller shaft for operating a rear steering device; a rear wheel steering control member controlling an inter-axis coupling; and a combining member(116) combining the key rod and rear wheel steering control member.

Description

DRIVING MODE CHANGEOVER APPARATUS INTEGRATED TRANSMISSION INTO STEERING DEVICE AND ELECTRIC WORKING DEVICE USING THE SAME}

The present invention relates to a driving mode conversion device integrated with a shifting and two-wheel / four-wheel steering switching function, and an agricultural electric work machine using the same, more specifically, the shift and two-wheel / four-wheel steering switching with one lever operation The driving mode converting apparatus is provided, which is convenient to use, and is equipped with a farming machine such as a manager or a vinyl coating machine at the rear thereof, and relates to an agricultural motorized work machine for agricultural work.

In general, for field farming, plowing the hardened soil and crushing the soil mass, making the ridges in the field before sowing, fertilizing the fertilizing process, installing vinyl coverings, and growing the crops Since a pesticide spraying process must be used to provide a variety of agricultural machinery, various agricultural machines such as managers and vinyl coating machines are used.

However, the conventional manager and the plastic cladding machine are people who work while holding the machine by hand, which requires a lot of labor and a long time, and has a problem that work efficiency is extremely reduced due to hard work. There is a need for a motorized work machine that can be equipped with agricultural machinery such as air conditioners and vinyl coating machines.

However, the conventional agricultural electric work machine is only possible to steer the front wheel two wheels because the rotation radius is large when the U-turn at the end of the field has a problem that the operation is inconvenient and work speed is lowered.

In particular, when working with a manager or vinyl coating machine at the rear of the agricultural work machine, it is necessary to drive at a low speed. In this case, steering of the wheel can be very easy to operate by reducing the turning radius. Improves.

In addition, it is necessary to drive at high speed during normal driving without work, in which case it is preferable that the two-wheel / four-wheel steering converter is mounted on the agricultural work machine because two-wheel steering is safe.

However, since the general driving mode conversion device is an electronic control device, the manufacturing cost is high, and there is a high risk of failure, so it is difficult to apply to an agricultural work machine.

In addition, since the driving mode converter must be installed as a separate device from the transmission, there is a disadvantage that the size of the work machine can not be compactly configured.

In order to solve this problem, the present invention provides a two-wheel / four-wheel steering device that can simplify the configuration while ensuring stability without fear of failure using only mechanical components without using any electronic elements. Its purpose is to.

In addition, an object of the present invention is to provide a traveling mode switching device capable of shifting and steering switching with one lever operation by shifting and steering switching functions integrated.

In addition, an object of the present invention is to provide a driving mode conversion device in which the shifting and steering functions are integrated so that two-wheel steering becomes safe for high-speed driving and four-wheel steering for low-speed driving.

In addition, another object of the present invention is to provide an agricultural motorized work machine equipped with a traveling mode converting device having a mechanically simple structure while shifting and steering switching functions are integrated.

In order to achieve the above object, in the present invention, a steering converting means configured to selectively enable two-wheel steering or four-wheel steering according to the operation of the operation lever, and to enable switching of low speed driving or high speed driving according to the operation of the operation lever. A traveling mode converting apparatus is provided, which comprises a configured speed converting means, so that the selection of two-wheel / four-wheel steering and the conversion of low speed / high speed are simultaneously performed by operation of one operation lever.

In the present invention, the steering converting means is axially coupled to the front wheel steering device for steering the front wheel and the first steering propulsion shaft rotated by the drive of the handle, and the rear wheel by transmitting the rotational force of the first steering propulsion shaft to the rear wheel steering device A second steering propulsion shaft for driving the steering apparatus, a rear wheel steering control means for regulating the coupling between the shafts so that the rotational force of the first steering propulsion shaft is transmitted to or disconnected from the second steering propulsion shaft, and forward and backward according to the operation of the operation lever. And a coupling member for coupling the key rod and the rear wheel steering control unit so that the key rod and the rear wheel steering control unit interlock with each other.

In this case, the rear wheel steering control means is coupled to the key rod by the coupling member so that the spline is formed at the rear end of the first steering propulsion shaft and the key rod moves forward and backward with the operation of the operation lever. The boss is coupled to the spline and the boss is released when the coupling with the spline, when the boss is coupled to the spline can be configured to transmit the rotational force of the first steering propulsion shaft to the second steering propulsion shaft.

In the present invention, the rear end of the key rod is inserted into the groove formed in the rear steering wheel gear when the reverse may be a fixed portion protruding to prevent the rear steering wheel gear to move.

In the present invention, a sliding slot may be formed in the operation lever so that the engaging projection formed in the key rod is fitted so that the key rod can be moved back and forth.

In the present invention, the speed conversion means is a high speed driving power transmission means for transmitting the rotational force of the electric motor at high speed to the propulsion shaft, low speed driving power transmission means for transmitting the rotational force of the electric motor to the propulsion shaft at low speed, and the high speed driving power A dog clutch selectively moved to a transmission means or a low speed driving power transmission means, and springs for selectively moving the dog clutch to the high speed driving power transmission means or the low speed driving power transmission means by moving back and forth according to the operation of the operation lever; The lever may be made.

In this case, the high speed driving power transmission means is composed of a first gear installed on the drive shaft, and a second gear meshed with the first gear and installed on the propulsion shaft to rotate the propulsion shaft at high speed, the low speed driving power transmission The means may comprise a third gear installed in the drive shaft and a fourth gear meshed with the third gear and installed on the propulsion shaft to rotate the propulsion shaft at low speed.

In the present invention, the spring lever may be installed to form a groove in a separate installation pipe fitted to the boss to move forward and backward in the state fitted in the groove.

In addition, the agricultural electric work machine of the present invention for achieving the above object is a driving unit configured to be driven by the electric motor driven by the battery power, and two-wheel steering or four-wheel steering in accordance with the operation of the operation lever Selection of two-wheel / four-wheel steering by operation of one operating lever, including steering converting means configured to be selectively enabled, and speed converting means configured to switch between low-speed driving or high-speed running according to the operation of the operating lever. And low speed / high speed conversion can be configured at the same time.

In the present invention, the engine unit configured to enable the connection of the work machine driven by the engine to the rear of the drive unit may be further included.

According to the present invention as described above, the two wheels / four wheels steering device is composed of only mechanical components, the cost is low, there is no fear of failure, while ensuring stability There is an effect that can be switched.

In addition, the transmission and the two-wheel / four-wheel driving mode conversion device is operated by one lever operation, it is possible to change the shift and steering in one operation has the effect of improving the convenience of the operator.

In addition, two-wheel steering is achieved during high-speed driving, and four-wheel steering is controlled during low-speed driving, so that the driving speed can be adjusted according to the working mode, thereby preventing the danger of high-speed driving, while driving at low speed while working. The ability to steer four wheels makes it very easy to maneuver the machine and improves the ability to turn in confined spaces when working on fields.

Therefore, it is possible to easily perform various kinds of farming work.

1 is a perspective view showing a working machine for farming electric vehicles equipped with a driving mode conversion device of the present invention,
Figure 2 is a plan view showing a motorized work machine for farming equipped with a driving mode conversion apparatus of the present invention,
3 is a right side view showing an electric motor work machine for farming equipped with a driving mode conversion device of the present invention;
4 is a plan view showing a steering converting means of the present invention;
5 is a perspective view showing a speed conversion means of the present invention,
6A is a plan view illustrating a front wheel steering state in a work machine equipped with a driving mode conversion device of the present invention;
FIG. 6B is a side view showing the key rod in FIG. 6A;
7A is a plan view showing a four-wheel steering state in a work machine equipped with a traveling mode conversion device of the present invention;
7B is a side view showing the key rod in FIG. 7A,
8 shows a speed converting means of the present invention, a perspective view showing a front wheel steering state;
Figure 9 is a perspective view showing a four-wheel steering state, showing the speed conversion means of the present invention.

Hereinafter, with reference to the drawings a traveling mode conversion device and a motor-operated electric work machine using the same, the shift and two-wheel / four-wheel steering switching function of the present invention will be described.

The driving mode converting apparatus of the present invention is applicable to a passenger vehicle having a front wheel and a rear wheel, and in the present invention, the driving mode converting apparatus of the present invention is mounted on an electric motorized work machine for farming in one embodiment. Let's do it.

1 is a perspective view showing an agricultural electric work machine equipped with a driving mode converter of the present invention, Figure 2 is a plan view showing an agricultural electric work machine equipped with a driving mode converter of the present invention, Figure 3 The right side view which shows the agricultural motorized work machine equipped with the driving mode changer of this invention.

Referring to this, an agricultural electric work machine equipped with a driving mode conversion device of the present invention is provided with two front wheels 1 and two rear wheels 3, respectively, and is used as a front wheel / rear wheel by an electric motor 2 driven by a battery. A driving unit configured to be capable of traveling and a mounting table capable of connecting various managers are provided at the rear of the driving unit.

The electric motor 2 is started by a battery (not shown) and transmits a driving force by a reduction gear connected to the motor shaft.

Such a work machine is equipped with an electric motor 2 so as to be electrically driven, but in addition to the electric motor, the driving mode converter of the present invention may be installed in the work machine driven by the engine, as well as the electric motor and the engine as well. It can also be applied to the hybrid work machine used.

The driving mode converting apparatus of the present invention comprises a steering converting means (100) configured to selectively enable two-wheel steering for steering only the front wheel (1) or four-wheel steering for simultaneously steering the front wheel (1) and the rear wheel (3); It is configured to include a speed conversion means 200 is configured to enable the switching of low-speed driving or high-speed driving.

In the present invention, the steering converting means 100 and the speed converting means 200 are configured to be converted at the same time as one operation lever 10 is operated.

That is, as shown in Figure 1, the operator is to make the two-wheel / four-wheel steering conversion and high speed / low speed speed conversion at a time through the operating lever 10 installed in a position that can be easily manipulated during operation.

To this end, the lever 10 is installed to interlock with a separate key rod 114, the lever 10 is hinged to a predetermined position in the work machine, the key rod 114 at the bottom of the lever 10 And the engaging protrusion 114a formed in the key rod 114 is formed by forming a sliding slot 12 that can be engaged with the key rod, thereby allowing the key rod to be centered on a hinged position according to the manipulation of the manipulation lever 10. 114 is installed so that forward and backward movement is possible.

Steering converting means 100 of the present invention includes the key rod 114, as shown in Figure 4, is axially coupled to the front wheel steering device for steering the front wheels 1 by the rotation of the handle (4) A first steering propulsion shaft 110 that rotates, a second steering propulsion shaft 112 for driving the rear wheel steering apparatus by transmitting a rotational force of the first steering propulsion shaft 110 to the rear wheel steering apparatus, and the first steering propulsion shaft; It comprises a rear wheel steering control means for regulating the coupling between the shaft so that the rotational force of the 110 is transmitted or broken to the second steering propulsion shaft (112).

The front wheel steering apparatus includes a bevel gear 25 meshing with a gear of a handle shaft 4a, and a front wheel steering gear gear for steering the front wheel 1 in engagement with a gear installed on the coaxial shaft of the bevel gear 25. 26), and the bevel gear 25 is engaged with the driven bevel gear 27 to which the first steering propulsion shaft 110 is coupled to rotate the rear wheel.

In such a front wheel steering device, when the handle 4 is rotated, the front wheel steering gear 26 is moved left and right to steer the front wheel 1.

At the rear end of the first steering propulsion shaft 110, a second steering propulsion shaft 112 for driving the rear wheel steering apparatus is installed, and the second steering propulsion shaft 112 and the first steering propulsion shaft 110 are connected to each other. Rear wheel steering control means for interrupting the shaft coupling is provided to be broken.

The rear wheel steering control means is moved forward and backward while being fitted to the splines 110a formed at the rear end of the first steering propulsion shaft 110 and the outer circumferential surfaces of the first steering propulsion shaft 110 and the second steering propulsion shaft 112. It is composed of the boss 120 is coupled to the spline (110a) when the reverse and the coupling with the spline (110a) when the reverse.

The boss 120 has a spline that can be engaged with the spline 110a and has a predetermined length on an inner circumferential surface thereof, and the coupling member moves forward and backward with the key rod 114 according to the manipulation of the manipulation lever 10. 116 is coupled with the keyrod 114.

The coupling member 116 is to be coupled to the key rod 114 and the boss 120 to interlock, it is not specified in the present invention.

By such a configuration, the boss 120 is moved forward and backward with the key rod 114 by the operation of the operation lever 10, and when coupled with the spline (110a) when moving forward, the first steering propulsion shaft ( The rotational force of 110 is transmitted to the second steering propulsion shaft 112.

The rear wheel steering apparatus includes a bevel gear 32 installed at a rear end of the second steering propulsion shaft 112, and a coaxial gear 34 meshing with a driven bevel gear engaged with the bevel gear 32. When the second steering propulsion shaft 112 rotates, the rear wheel steering gear 36 rotates, thereby steering the rear wheel 3.

On the other hand, a groove through which the front end of the key rod 114 passes is formed in the upper surface of the front wheel steering gear gear 26, and a rear end of the key rod 114 is formed in the upper surface of the rear wheel steering gear gear 36. Grooves 36a are formed to be fixed.

At the rear end of the key rod 114, a fixing part 114b is inserted into the groove 36a formed in the rear steering wheel gear 36 to prevent the rear steering wheel gear 36 from moving.

The fixing part 114b is separated from the rear wheel steering gear 36 when the key rod 114 moves forward to allow the rear wheel steering gear 36 to move from side to side. The rear wheel steering rack gear 36 does not move by being fitted into the groove 36a formed on the upper surface of the cylinder 36.

5 is a perspective view showing a speed conversion means of the present invention, the speed conversion means 200 is a high speed driving power transmission means for transmitting the rotational force of the electric motor 2 to the propulsion shaft at high speed, and the propulsion shaft of the electric motor Slow driving power transmission means for transmitting at a low speed to the speed, the dog clutch 242 is selectively moved to the high speed driving power transmission means or low speed driving power transmission means, and forward and backward in accordance with the operation of the operation lever 10 And a spring lever 244 for selectively moving the dog clutch 242 to the high speed driving power transmission means or the low speed driving power transmission means.

Here, the high speed driving power transmission means and the first gear 254 is installed on the drive shaft 262 to receive the driving force by the reduction gear 252 meshing with the gear connected to the motor shaft of the electric motor (2), and The second gear 256 is meshed with the first gear 254 and installed on the propulsion shaft 264 to rotate the propulsion shaft 264 at high speed.

The first gear 254 is composed of a gear having more teeth than the second gear 256 to rotate the propulsion shaft 264 at high speed.

On the other hand, the low-speed driving power transmission means is engaged with the third gear 272 and the third gear 272 is installed on the drive shaft 262 and installed on the propulsion shaft 264 to rotate the propulsion shaft 264 at low speed The fourth gear 274 to be made.

The third gear 272 is composed of a gear having fewer teeth than the fourth gear 274 to rotate the propulsion shaft 264 at a low speed.

The spring lever 244 is composed of an elastic body to move back and forth the dog clutch 242 in accordance with the operation of the operation lever 10, in the present invention, one end of the spring lever 244 in the working machine Is fixed to a predetermined position, the other end is fitted into the groove 132 formed in a separate installation pipe 130 fitted to the boss 120 is configured to move forward and backward with the boss 120, the spring lever 244 The central portion of the dog clutch 242 is configured to be able to move the dog clutch 242 elastically when the other end is advanced back and forth with the boss 120.

According to the present invention, the spring lever 244 is made of an elastic body, so that the boss 120 of the dog clutch 242 when the boss 120 moves the 'A' interval (38mm) of FIG. 6 by operating the operating lever 10. Even if teeth are not contacted with each other, the spring lever 244 may be bent and the dog clutch 242 may be engaged as the electric motor 2 rotates.

Therefore, the speed converting means of the present invention is the dog clutch 242, the first gear 254 / second gear 256 for high speed driving or the third gear 272 / fourth gear 274 for low speed driving By moving to), it is possible to switch between driving mode moving at high speed and working mode moving at low speed.

Referring to the operation of the agricultural work machine for farming in this configuration is as follows.

Fig. 6A is a plan view showing a front wheel steering state in a work machine equipped with a drive mode conversion device of the present invention, Fig. 6B is a side view showing a key rod in Fig. 6A, and Fig. 7A is mounted with a drive mode conversion device of the present invention. Fig. 7B is a side view showing the key rod in Fig. 7A, and Fig. 8 is a perspective view showing the front wheel steering state, showing the speed converting means of the present invention. 9 shows a speed converting means of the present invention, and is a perspective view showing a four-wheel steering state.

The agricultural motorized working machine of the present invention can adjust the traveling speed according to the driving mode and the working mode, is configured to be maneuverable to the front wheel steering in the driving mode, four-wheel steering in the working mode.

First, as a condition for operating the operating lever 10, the wheel is aligned to the center position so that the key rod 114 in a position where it can pass through the groove of the front wheel steering gear 26, the operating lever 10 When the key rod 114 is reversed by manipulating the boss 120 coupled to the key rod 114 by the coupling member 116, the boss 120 moves backward on the second steering propulsion shaft 112 to operate the first steering propulsion shaft 110. It is not coupled with the spline 110a of the.

In this case, when the handle 4 is rotated, the first steering propulsion shaft 110 rotates, but the spline 110a is removed from the boss 120, so that the rotational force is not transmitted to the second steering propulsion shaft 112. The rear wheel steering gear 36 does not rotate.

In addition, since the fixing portion 114b of the key rod 114 is fitted in the groove 36a of the rear wheel steering gear 36, the rear wheel steering gear 36 cannot move and only front wheel steering is possible.

In addition, as the spring lever 244 fitted into the groove 132 formed in the installation pipe 130 is moved backward as the boss 120 retracts, the dog clutch 242 has a first gear for high speed driving. 254 / second gear 256 is engaged to be able to travel at high speed.

Therefore, by reversing the operation lever 10, it is possible to switch to the high speed driving mode at the same time as the front wheel steering.

On the other hand, in the case of the working mode, when the wheel is to be run at a low speed, the wheel is aligned to the center position so that the key rod 114 is positioned at the position where the front wheel steering gear 26 can pass through the groove and the operator operates the operation lever ( 10), the key rod 114 is moved forward, and the tip portion of the key rod 114 passes through a groove formed in the upper surface of the front wheel steering rack gear 26 to protrude outward, as shown in FIG. 7B. The boss 120 is advanced on the second steering propulsion shaft 112 and coupled to the spline 110a of the first steering propulsion shaft 110.

In this case, since the first steering propulsion shaft 110 rotates and the spline 110a is coupled to the boss 120 when the handle 4 is rotated, the rotational force is transmitted to the second steering propulsion shaft 112 so that the rear wheels are rotated. The steering rack gear 36 is rotated.

In addition, since the fixing part 114b of the key rod 114 is separated from the groove 36a of the rear wheel steering gear 36, the rear wheel steering gear 36 can move, so that the rear wheel steering can be performed. Becomes

In addition, the spring lever 244 fitted into the groove 132 formed in the installation pipe 130 is advanced as the boss 120 moves forward, so that the dog clutch 242 has a third gear for low speed driving. It is engaged with the 272 / fourth gear 274, it is possible to travel at a low speed.

Therefore, by advancing the operation lever 10, it can be switched to the low speed driving mode simultaneously with the four-wheel steering.

In the case of such a four-wheel steering, the steering wheel operation of the work machine not only controls the front wheels but also the rear wheels, so that it is very easy to operate the work machine at a low speed, and in particular, it is possible to reduce the shaking of the rear side of the vehicle caused by slippage, It improves stability when driving with vinyl packing machine.

While the invention has been described in detail with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

1: front wheel 2: electric motor
3: rear wheel 4: steering wheel
10: operation lever 12: sliding slot
100: steering conversion means 114: key rod
114a: engaging projection 110: the first steering propulsion shaft
112: second steering propulsion shaft 110a: spline
120: boss 116: coupling member
200: speed conversion means 242: dog clutch
244: spring lever 254: first gear
256: second gear 272: third gear
274: fourth gear

Claims (13)

delete Is coupled to the lower end of the operation lever is provided with a key rod that can be moved back and forth in accordance with the operation of the operation lever,
And a steering converting means and a speed converting means for simultaneously switching to four-wheel steering and a low-speed driving mode when the key rod is moved forward, and simultaneously switching to two-wheel steering and a high-speed driving mode when the key rod is reversed.
The steering converting means is axially coupled to a front wheel steering device for steering the front wheels and transmits a rotational force of the first steering propulsion shaft to the rear wheel steering device to transmit the rotational force of the first steering drive shaft to the rear wheel steering device. A second steering propulsion shaft, a rear wheel steering regulating means for regulating the coupling between the shafts so that the rotational force of the first steering propulsion shaft is transmitted to or disconnected from the second steering propulsion shaft, and the key rod and the rear wheel steering regulating means interlock with each other. A coupling member for coupling the key rod and the rear wheel steering control means,
The speed converting means includes high speed driving power transmission means for transmitting the rotational force of the electric motor to the propulsion shaft at high speed, low speed driving power transmission means for transmitting the rotational force of the electric motor to the propulsion shaft at low speed, and the high speed driving power transmission means or the low speed. A dog clutch selectively moved to a traveling power transmission means and an elastic body interlocked with the rear wheel steering control means and moved forward and backward according to the operation of the operation lever to move the dog clutch to the high speed driving power transmission means or the low speed driving power transmission means. Consisting of a spring lever for selectively moving to the means,
The rear end of the key rod is formed in the groove formed in the rear steering wheel gear when the rear portion is fixed to prevent the rear steering wheel gear from moving,
When the key rod is advanced, the first steering propulsion shaft and the second steering propulsion shaft are connected by the rear wheel steering control means, so that the rear wheel steering device is operated, and thus, the four-wheel steering enables the dog clutch to slow down the dog clutch. Engages with the driving power transmission means, switches to the low-speed driving mode,
When the key rod is retracted, the fixed part is inserted into a groove formed on the upper surface of the rear steering wheel gear, so that the rear steering wheel is not moved, and the first steering drive shaft and the second steering drive shaft are connected by the rear wheel steering control means. And the front wheel steering is released, and at the same time, the spring lever engages the dog clutch with the high speed driving power transmission means and switches to the high speed driving mode. The method of claim 2,
The rear wheel steering control means,
A spline formed at a rear end of the first steering propulsion shaft;
The boss is coupled to the key rod by the coupling member so as to move forward and backward with the key rod according to the manipulation of the operation lever, and the boss is coupled to the spline when moving forward and the coupling with the spline is released when moving backward.
And the boss is coupled to the spline to transfer the rotational force of the first steering propulsion shaft to the second steering propulsion shaft. delete The method of claim 2,
And a sliding slot is formed in the operation lever so that a coupling protrusion formed in the key rod is inserted to allow the key rod to move forward and backward. delete The method of claim 2,
The high speed driving power transmission means and the first gear is installed on the drive shaft;
A second gear meshed with the first gear and installed on a propulsion shaft to rotate the propulsion shaft at high speed;
The low speed driving power transmission means and the third gear is installed on the drive shaft;
And a fourth gear meshed with the third gear and installed on the propulsion shaft to rotate the propulsion shaft at low speed. The method of claim 2,
The spring lever is a driving mode conversion device, characterized in that for forming a groove in a separate installation pipe fitted to the boss to advance back and forth in the state fitted in the groove. A driving unit configured to be driven by an electric motor driven by a battery power source;
A key rod coupled to a lower end of the operation lever and capable of advancing back and forth according to the operation of the operation lever;
And a steering converting means and a speed converting means for simultaneously switching to four-wheel steering and a low-speed driving mode when the key rod is moved forward, and simultaneously switching to two-wheel steering and a high-speed driving mode when the key rod is reversed.
The steering converting means is axially coupled to a front wheel steering device for steering the front wheels and transmits a rotational force of the first steering propulsion shaft to the rear wheel steering device to transmit the rotational force of the first steering drive shaft to the rear wheel steering device. A second steering propulsion shaft, a rear wheel steering regulating means for regulating the coupling between the shafts so that the rotational force of the first steering propulsion shaft is transmitted to or disconnected from the second steering propulsion shaft, and the key rod and the rear wheel steering regulating means interlock with each other. A coupling member for coupling the key rod and the rear wheel steering control means,
The speed converting means includes high speed driving power transmission means for transmitting the rotational force of the electric motor to the propulsion shaft at high speed, low speed driving power transmission means for transmitting the rotational force of the electric motor to the propulsion shaft at low speed, and the high speed driving power transmission means or the low speed. A dog clutch selectively moved to a traveling power transmission means and an elastic body interlocked with the rear wheel steering control means and moved forward and backward according to the operation of the operation lever to move the dog clutch to the high speed driving power transmission means or the low speed driving power transmission means. Consisting of a spring lever for selectively moving to the means,
The rear end of the key rod is formed in the groove formed in the rear steering wheel gear when the rear portion is fixed to prevent the rear steering wheel gear from moving,
When the key rod is advanced, the first steering propulsion shaft and the second steering propulsion shaft are connected by the rear wheel steering control means, so that the rear wheel steering device is operated, and thus, the four-wheel steering enables the dog clutch to slow down the dog clutch. Engages with the driving power transmission means, switches to the low-speed driving mode,
When the key rod is retracted, the fixed part is inserted into a groove formed on the upper surface of the rear steering wheel gear, so that the rear steering wheel is not moved, and the first steering drive shaft and the second steering drive shaft are connected by the rear wheel steering control means. And the front wheel steering is possible, and at the same time the spring lever engages the dog clutch with the high speed driving power transmission means and is configured to switch to the high speed driving mode. 10. The method of claim 9,
And an engine unit configured to enable connection of a work machine driven by an engine to a rear portion of the driving unit. delete 10. The method of claim 9,
The rear wheel steering control means,
A spline formed at a rear end of the first steering propulsion shaft;
The boss is coupled to the key rod by the coupling member so as to move forward and backward with the key rod according to the manipulation of the operation lever, and the boss is coupled to the spline when moving forward and the coupling with the spline is released when moving backward.
And the boss is coupled to the spline to transfer the rotational force of the first steering propulsion shaft to the second steering propulsion shaft. delete

Images