JP2001018670A - Traveling device for asphalt finisher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent an unexpected run-away at the time of a slope parking by rotating a hydraulic motor by pressure oil from a hydraulic pump driven by an engine, traveling and driving a rear wheel via a clutch for high speed or a clutch for low speed and performing braking by a negative actuation brake when the engine is stopped. SOLUTION: When a hydraulic motor 2 is rotated by pressure oil from a hydraulic pump, rotation of a drive shaft 4 is transmitted to a rotation casing 1A via a negative actuation clutch 8 for high speed or a positive actuation clutch 9 for low speed and a rear wheel is traveled and driven. In this case, because supply of pressure oil to a pressure oil chamber of a negative actuation brake 3 from a hydraulic pump through a pressure oil path 13 and supply of pressure oil to a pressure oil path 22 leading to the negative actuation clutch 8 are stopped when an engine is stopped, a piston body 3b of the negative actuation brake 3 is made to hold and fix friction ring bodies 3e, 3h by force of a spring 11, the hydraulic motor 2 is fixed to a fixing casing 1B by the frictional force and braking force is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling device having means for safely traveling and stopping in a wheel type asphalt finisher driven by a hydraulic motor.

[0002]

2. Description of the Related Art Conventionally, a traveling device of a wheel type asphalt finisher has been improved from a direct drive system to a hydraulic drive system, and its power transmission mechanism is operated by an engine 51 as shown in FIG. Drive the hydraulic motor 53 with pressure oil from the hydraulic pump 52 to
The chain is transmitted to a chain 56 and a sprocket wheel 57 which extends around the chain 56 endlessly via a speed reducer 54 and a differential gear 55, and the rear wheel 58 of the asphalt finisher is rotated.

[0003] The speed adjustment at the time of construction is performed by a hydraulic pump.
When the traveling speed is largely changed, for example, by switching the pavement construction to the forward traveling posture, by controlling the discharge amount of the pressurized oil from the 52, a transmission mechanism built in the reduction gear 54 is used. ing. A brake for braking the traveling is provided by a speed reducer 54 or a differential gear 55.
Mounted on Further, the differential gear 55 is provided with a non-spin differential mechanism or a differential lock mechanism that generates a traction drive force on the other rear wheel when one rear wheel is fitted on a soft roadbed or a stepped road surface to be in a spin state.

[0004]

However, according to the asphalt finisher traveling apparatus having the above structure, the traveling braking of the rear wheels, in other words, the traveling braking of the entire asphalt finisher is applied to the chain 56. If the 56 breaks, not only will the asphalt finisher be unable to run or brake, but if the asphalt finisher is running down a hill, the chain 56 will have no way of braking and will be extremely dangerous. .

As a countermeasure, an asphalt finisher equipped with a traveling mechanism employing gear transmission instead of the transmission means by the chain 56 is sold in foreign countries. Because the gear case receives the rear wheel load and traction force, the gear case needs strength and rigidity to withstand the load, which increases the weight and bulk, which is an essential condition for a domestically produced asphalt finisher. There has been a problem that it is impossible to obtain an inspection for a large special automobile.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described various problems, and has as its object to provide an unintentional system for parking on a slope by directly connecting to a rear wheel without employing chain transmission. The present invention is to provide a lightweight and compact asphalt finisher traveling device capable of reliably preventing runaway of the vehicle, and generating a traction drive force on the other rear wheel when one of the rear wheels is in a spin state. .

[0007]

According to a first aspect of the present invention, there is provided a traveling device for an asphalt finisher which is directly connected to the rear wheels as hubs of both rear wheels of the asphalt finisher. A rotating casing, and a fixed casing fixed to a frame side of the asphalt finisher and rotatably supporting the rotating casing. The fixed casing incorporates a hydraulic motor and a negative operation brake for braking the rotation of the hydraulic motor. On the other hand, a drive shaft that rotates integrally with the hydraulic motor extends to the rotary casing side, and the rotation of the drive shaft is either a high-speed clutch provided in the rotary casing or a low-speed clutch connected to a reduction mechanism. A reduction gear that can be transmitted to the rotating casing via one of the When the engine is stopping of the turbocharger is configured so as to brake the rotating casing by the negative actuation brake.

In the traveling device for the asphalt finisher, the invention according to a second aspect is characterized in that a hydraulic oil supply line from a hydraulic pump operated by an engine is passed through a branch line through a branch valve to a hydraulic pressure for driving the two rear wheels. A differential lock mechanism that communicates with the motor and connects these branch conduits by a coupling conduit having a switching valve to perform differential lock and differential lock release is configured.

The invention according to claim 3 is characterized in that a disk brake which is operated by depressing a brake pedal in a driver's seat is mounted on the speed reducer.

Further, in the asphalt finisher traveling device according to the first or third aspect, the invention according to a fourth aspect is arranged such that a pressure switch is disposed in a brake circuit by a brake pedal, and the brake pedal is depressed. The pressure switch is operated to stop the supply of the pressure oil to the hydraulic motor by the electric signal.

[0011]

When hydraulic oil is supplied from a hydraulic pump operated by engine driving to a hydraulic motor and the hydraulic motor is rotated, the drive shaft rotates integrally and the rotation is connected to a high-speed clutch or a speed reduction mechanism. And transmitted to the rotating casing via one of the clutches for driving the rear wheels directly.

At this time, a disk clutch that sandwiches a friction ring plate and transmits a rotational force is used as the high-speed and low-speed clutches, and the high-speed disk clutch is opposed by the supply of pressure oil. When the disks are separated from each other against the spring force and the supply of the pressure oil is stopped, the discs approach each other due to the spring force and clamp the friction ring plate. The positive-acting clutch is a positive-acting clutch in which the opposing disks approach each other against the spring force to clamp the friction ring plate and the disks are separated by the spring force when the supply of pressure oil stops. Is connected to a reduction mechanism such as a planetary gear mechanism, so that the speed of the drive shaft is reduced by the reduction mechanism during pavement Transmitted to the rotating casing via the clutch, to rotate the rear wheel with a vehicle speed and driving force that is suitable for pavement construction. Also, unlike pavement construction, it does not require much driving force during transportation, but because high-speed running is required, the supply of pressure oil for clutch operation is cut off and both disks of the negative operation clutch are spring-loaded. A frictional connection is made by force, and the rotation of the drive shaft is transmitted to the rotary casing via the negative operation clutch to rotate the rear wheel at high speed.

Next, when the engine is turned off, the negative operation brake is operated to stop the rotation of the hydraulic motor, and the rotational force of the rotary casing is supported on the fixed casing side via the negative operation clutch. Therefore, even if the asphalt finisher parks in the middle of a slope, it does not accidentally escape.

According to the second aspect of the present invention, during normal construction and running, the flow rate according to the rotation difference between the two rear wheels from the pressure oil supply line to the branch line via the branch valve and the connection line. Are supplied to the respective drive hydraulic motors of the two rear wheels to enable straight running and turning motion, and when one of the rear wheels spins due to a soft roadbed or the like, a switch provided in the connection pipe line is provided. By closing the connecting line by the valve, the pressure oil diverted 1: 1 from the diverting valve is supplied to both branch lines to generate a driving force on the other rear wheel, and the asphalt finisher is used as a differential lock mechanism. It is towing.

Further, in the invention according to claim 3,
A disc brake that operates by depressing the driver's seat brake pedal is mounted on the reduction gear that is directly connected to both rear wheels as a hub, so the brake pedal must be depressed from the driver's seat even when the asphalt finisher is traveling on an ordinary road. As a result, rapid braking that cannot be obtained with the above-mentioned negative operation brake is enabled, and the vehicle can travel safely. In addition, since it is a disc brake, the distance between both rear wheels can be widened, so that the width of the pavement material provided between both rear wheels can inevitably be set to a wide width, and as an asphalt finisher Can fully demonstrate its conveyor capacity.

According to the fourth aspect of the present invention, the pressure switch is operated by depressing the brake pedal, and the supply of the pressure oil to the rear wheel drive hydraulic motor is stopped by the electric signal. As a result, not only the driving force of the rear wheel by the hydraulic motor is shut off, but also the traveling braking force acts on the hydraulic motor, and the braking distance of the asphalt finisher by the brake pedal is shortened.
A safer and more reliable braking mechanism can be provided.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional side view of a speed reducer A, and FIGS. As shown in FIGS. 4 to 6, the speed reducer A is mounted in the hub holes of the wheels of the rear wheels C in the asphalt finisher B, and the rear wheels C are built in the respective speed reducers A. It is configured to be driven to rotate by the hydraulic motor 2 that is operating.

The speed reducer A is inserted into a hub hole of a wheel of a rear wheel B of an asphalt finisher B, and is fixed to a rotary casing 1A by bolts around the hub hole.
And one side of the rotating casing 1A
Casing rotatably supported through bearings and attached to the frame side of asphalt finisher B
1B, the fixed casing 1B includes a hydraulic motor 2 and a negative operation brake 3 for braking the rotation of the hydraulic motor 2 as shown in FIGS. As shown in FIG. 1 and FIG.
And an eccentric oscillating reduction mechanism 5 for reducing the rotation transmitted from the drive shaft 4 via the drive shaft 4 to output the rotation to the rotary casing 1A, and connecting the eccentric oscillating reduction mechanism 5 to the rotation from the drive shaft 4 side. Clutch drum 6 transmitted to the eccentric oscillating reduction gear mechanism 5
And a planetary gear mechanism 7 disposed at the other end of the drive shaft 4.
A negative operating clutch 8 disposed in the rotating frame 6 for transmitting or blocking the rotation of the drive shaft 4 to the clutch drum 6 for high speed; and a driving shaft 4 also disposed in the clutch drum 6. A positive operating clutch 9 for transmitting the rotation transmitted through the planetary gear mechanism 7 to the clutch drum 6 or interrupting the transmission is provided.

The drive shaft 4 is horizontally disposed at the center of the rotating casing 1A and the fixed casing 1B, and one end thereof is rotatably supported by the center of the inner surface of the cover plate 1b of the fixed casing 1B. The end is rotatably supported at the center of the inner surface of the lid plate 1a having the open end of the rotary casing 1A closed, and the middle part is divided and connected by the coupling 10. The hydraulic motor 2 is disposed at one end of the drive shaft 4, that is, in the fixed casing 2.

The hydraulic motor 2 is composed of a well-known swash plate type hydraulic motor, and is disposed in a chamber 2a provided at the center of the fixed casing 1B as shown in FIG. And a plurality of cylinder portions 2c formed in the cylinder block 2b.
A plunger 2d slidably disposed on the plunger 2d;
A shoe 2e swingably attached to the other end of 2d, and a supply / discharge port interposed between one side end surface of the cylinder block 2b and the cover plate 1b to supply / discharge pressure oil to / from the cylinder portion 2c. A timing plate 2f, and a swash plate 2g, which is arranged to be tiltable on the other end surface side of the chamber 2a of the fixed casing 2 so as to face the cylinder block 2b and has an inclined surface with which the shoe 2e is slidably contacted. By sliding the shoe 2e on the inclined surface of the swash plate 2g inclined in the circumferential direction by moving the plurality of plungers 2d forward and backward by the supply and discharge of the pressure oil supplied through the supply and discharge opening of the cylinder portion 2c. The rotation of the cylinder block 2 b is transmitted to the drive shaft 4. The swash plate 2g is configured such that the degree of inclination is changed in two stages by a piston 2h in a cylinder chamber provided at the other end of the fixed casing 1B to change the rotation speed of the hydraulic motor 2.

The negative operation brake 3 disposed in the fixed casing 1B is a disc brake, and
A cylinder portion 3a having a small diameter portion and a large diameter portion is formed on the outer peripheral surface of one end portion of the cylinder portion 2a. The cylinder part 3a is provided at several places on the outer peripheral part between the small diameter part tip surface of the body 3b and the vertical end surface of the small diameter part of the cylinder part 3a.
A friction ring plate 3e provided with a claw 3d slidably front and rear in a groove 3c formed on the inner peripheral surface of the small diameter portion of the small diameter portion, and an outer periphery of the cylinder block 2b at several locations on the inner peripheral portion. A plurality of friction ring plates 3h provided with pawls 3g slidably slidably back and forth are alternately interposed in groove grooves 3f engraved in the length direction on the surface. A spring 11 that constantly presses the piston body 3b toward the ring plate is interposed on the opposite surface of the large-diameter portion back (one side surface) of the 3b and the cover plate 1b, and the large-diameter portion of the piston body 3b and the cylinder portion 3a A pressure oil chamber 12 is formed between the large-diameter portion and the vertical end surface, and pressure oil is supplied to the pressure oil chamber 12 through a first pressure oil passage 13.

Accordingly, when the pressure oil is supplied to the pressure oil chamber 12, the piston body 3b retreats to one side against the force of the spring 11, and releases the friction ring plates 3e, 3h, When the supply of pressure oil to the pressure oil chamber 12 is cut off while the rotation of the hydraulic motor 2 is enabled, the force of the spring 11 causes the piston body 3b to move forward and its distal end face to the cylinder portion on the fixed casing 1B side.
The friction ring plates 3e and 3h are sandwiched between the small diameter portion 3a and the vertical end face of the small diameter portion 3a, and the hydraulic motor 2 is braked.

The eccentric oscillating type speed reduction mechanism 5 disposed in one side of the rotary casing 1A is disposed at a constant distance from the other side of the fixed casing 1B to the other side. Between the fixed support plate 14 and the two disc-shaped gear bodies 5a and 5b.
Are disposed eccentrically to each other, and teeth 5c, 5d projecting at small intervals in the circumferential direction on the outer peripheral surfaces of these disc-shaped gear bodies 5a, 5b are provided inside one side of the rotary casing 1A. Disc gears 5a and 5b are detachably engaged with a large number of engagement pins 5e fixed to the peripheral surface at small intervals in the circumferential direction.
An output gear 15 is fixed to a shaft end of the crankshaft 5f protruding from the fixed support plate 14 to the other side of the crankshaft 5f.

More specifically, the drive shaft 4 is inserted through the center of the disk gears 5a and 5b, and the disk gears 5a and 5b
a and 5b are provided with holes sized to be eccentrically oscillating, and a hole through which a bolt fixing the fixed support plate 14 to the other side surface of the fixed casing 1B is inserted into the outer peripheral portion and the crank shaft 5f. The crankshaft 5f is rotatably supported at both ends thereof by the fixed casing 1B and the fixed support plate 14, and is further circular than the engagement pin 5e. The number of teeth 5c, 5d of the plate-shaped gear bodies 5a, 5b is reduced, and the disk-shaped gear bodies 5a, 5b are eccentrically oscillated by the crankshaft 5f which rotates integrally with the rotation of the output gear 15, and the eccentricity thereof The rotating casing 1A is rotated at a reduced speed while the tooth portions 5c and 5d are disengaged from the engaging pins 5e by swinging to drive the rear wheel C of the asphalt finisher B.

The clutch drum 6 disposed in the rotary casing 1A on the other side of the eccentric oscillating speed reduction mechanism 5
Has a shape in which a disk portion 6b is integrally formed at one end of the cylindrical portion 6a and the other end is entirely open as shown in FIG. 3,
A small-diameter internal gear 17 meshed with an intermediate gear 16 rotatably fitted on the drive shaft 4 is provided integrally at the center of the disk portion 6b, while the drive shaft is provided on the inner peripheral surface of the cylindrical portion 6a. A plurality of ridges 6c which are long in the length direction 4 are provided at predetermined intervals in the circumferential direction. The intermediate gear 16 is meshed with the output gear 15 so that the rotation of the clutch drum 6 is transmitted from the small-diameter internal gear 17 to the eccentric oscillating reduction mechanism 5 via the intermediate gear 16 and the output gear 15. are doing. Further, the clutch drum 6 is provided with the negative operation clutch 8 and the positive operation clutch 9 formed of a disk clutch.

The negative actuating clutch 8 is provided with a receiving disk 8a having a center portion spline-fitted to the drive shaft 4, and a negative disk 8a provided on one side of the receiving disk 8a so as to be able to freely contact and separate from the receiving disk 8a. Movable disk 8b and these disks 8
a, 8b, and a plurality of friction ring plates 8c, 8d interposed alternately in a superposed state, and these friction ring plates 8c, 8d project from one side surface of the receiving disk 8a. Claws 8f which are disposed on the portion 8e and are engaged with the ridges 6c of the clutch drum 6 are provided at a plurality of positions on the outer peripheral portion of one friction ring plate 8c,
On the inner peripheral surface of the other friction ring plate 8d, there is provided a claw 8h engaged with a protruding ridge 8g projecting from the outer peripheral surface of the projecting ring portion 8e at several places.

Further, a spring receiving plate 18 is provided on one side of the movable disk 8b, and a spring 19 is interposed between a surface of the spring receiving plate 18 and the movable disk 8b. Disk 18 Receiving disk 8a
The pressure oil chamber 20 is provided on the inner peripheral surface of the receiving disk 8a and the movable disk 8b, and the pressure oil chamber 20 is provided in the center of the drive shaft 4 from within the fixed casing 1B. An oil passage 21 provided through the spring receiving plate 18 and the receiving disk 8a is communicated, and pressure oil is supplied to the oil passage 21 from outside the fixed casing 1B through a second pressure oil passage 22. . The spring receiving plate 18 is fitted on the drive shaft 4 and the receiving disk 8b is received by a fixed plate 23 having the other side surface fixed on the drive shaft 4 at a fixed position.

On the other hand, the positive-acting clutch 9 is connected to a receiving disk 9a whose center portion is rotatably fitted to the drive shaft 4, and one side of the receiving disk 9a is in contact with the receiving disk 9a. A movable side disk 9b detachably provided and a plurality of friction ring plates 9c and 9d alternately interposed between the disks 9a and 9b in a superposed state.
a and 9b are disposed on a projecting ring 9e projecting from one side surface of the receiving disk 9a, and at a plurality of locations on the outer peripheral portion of one friction ring plate 9c on the projecting ridges 6c of the clutch drum 6. Engaged claw
On the inner peripheral surface of the other friction ring plate 9d, there is provided a claw 9h engaged with a ridge 9g protruding at several places on the outer peripheral surface of the projecting ring portion 9e.

The movable disk 9b is a receiving disk.
The inner peripheral surface of a small-diameter annular body 24 that is integrally connected to the receiving-side disk 9a at one side of the receiving disk 9a at a predetermined interval and that is rotatably fitted to the drive shaft 4. It is fitted slidably back and forth and a spring 25 is interposed between the friction ring plate facing the receiving disk 9a, and the movable disk 9b is pressed by the spring force in a direction to always separate from the receiving disk 9a. Further, a pressure oil chamber 26 is provided on an opposing surface of one side surface of the inner peripheral portion of the receiving disk 9a and one side flange portion of the small diameter annular body 24, and the second oil pressure passage is provided in the pressure oil chamber 26. 22 are connected.

Further, the positive working clutch 9 and the rotary casing
The planetary gear mechanism 7 is disposed between the planetary gear mechanism 7 and the cover plate 1a of 1A. The planetary gear mechanism 7 includes a sun gear 7a spline-fitted to the other end of the drive shaft 4, an internal gear 7b formed on the inner peripheral surface of the cover plate 1a, and a sun gear 7a and an internal gear 7a. It comprises several planetary gears 7c meshing with 7b and a carrier 7d rotatably supporting the planetary gears 7c.
7d is integrally connected to the receiving disk 9a of the positive working clutch 9.

As shown in FIG. 7, a disc brake 27 is mounted on the outer peripheral surface of the rotary casing 1A of the speed reducer A constructed as described above, and the disc brake 27 operates by depressing a brake pedal 28. The rotation of the rotary casing 1A is configured to be braked. That is,
When the brake pedal 28 is depressed, the master cylinder
Pressure oil is generated in 29 and the disc brake 27 is operated via a pressure switch 30. FIG. 8 is an electric circuit diagram thereof.

FIG. 9 shows two rear wheels C, C of an asphalt finisher B from a hydraulic pump 32 operated by an engine 31.
A hydraulic circuit for supplying pressure oil to the speed reducer A directly connected as a hub to the asphalt finisher B via the speed reducer A based on the electric circuit diagram and the hydraulic circuit. The stop mode will be described below.

First, when the engine 31 is driven, the hydraulic pump
32 operates to supply pressure oil to the first pipeline 33. At this time,
Since the brake pedal 28 is in a non-operating state, the pressure switch 30 does not operate, and the switching valve 34 provided in the first line 33 is switched by the operation of the solenoid 35, and is connected to and communicated with the first line 33. Oil pressure is supplied from the first pressure oil passage 13 to the pressure oil chamber 3f of the negative operation brake 3 so that the piston body 3b retreats to one side against the force of the spring 3e and the friction ring plates 3e, 3h Is released, and the rotation of the hydraulic motor 2 is enabled. In addition,
When the engine 31 is not operating, the hydraulic pump 32 does not discharge the pressure oil, and therefore the pressure oil is not supplied to the pressure oil chamber 3f of the negative operation brake 3.

Further, at the time of pavement or the like, the switching valve 37 provided in the second conduit 36 connected and connected to the hydraulic pump 32 is switched by the operation of one of the solenoids 38 to switch the hydraulic pump 32 from the hydraulic pump 32. When pressure oil is supplied to the second pressure oil passage 22 in the reduction gear A communicating with the second passage 36 through the second passage 36, the pressure oil is connected to the negative operation clutch 8 through the second pressure oil passage 22. On the negative operation clutch 8 side, the movable side disk 8b is separated from the receiving side disk 8a against the force of the spring 19, and is pressed into the pressure oil chambers 20 and 26 with the positive operation clutch 9. The rotation of the receiving disc 8a spline-fitted to the drive shaft 4 is not transmitted to the clutch drum 6, although the friction ring plates 8c and 8d interposed between the clutch discs 8b are released. On the working clutch 9 side, the supply of pressure oil into the pressure oil chamber 26 is enabled. The moving-side disc 9b is pushed toward the receiving-side disc 9a against the force of the spring 25, and the friction ring plates 9c and 9d are clamped by these discs 9a and 9b.

Accordingly, the clutch drum 6 and the planetary gear mechanism 7 are integrally connected via the positive operation latch 9, and the rotational force of the drive shaft 4 driven to rotate by the hydraulic motor 2 is reduced by the planetary gear mechanism 7. This clutch drum 6 transmitted to the clutch drum 6 and having increased driving force due to deceleration
Is further transmitted from the intermediate gear 16 meshing with the small-diameter internal gear 17 of the clutch drum 6 to the crankshaft 5f of the eccentric oscillating reduction mechanism 5 via the output gear 15 to thereby form the disk gear 5a. , 5b is eccentrically oscillated and the rotating casing 1A is further decelerated and rotated via the engaging pin 5e which engages with the gears 5c and 5d, so that the driving force is further increased and the rear wheel C is rotated suitable for pavement construction. To make the asphalt finisher B run at low speed.

When the asphalt finisher B travels to a work site or the like, when the other solenoid 38 'of the switching valve 37 provided in the second conduit 36 is excited, the switching valve 37 is switched in the opposite direction. On the other hand, no pressure oil is supplied from the hydraulic pump 32 to the oil passage 21 in the reduction gear A, and therefore, on the side of the negative operation clutch 8, the movable side disk 8 b is moved by the force of the spring 19 to the receiving side disk 8 a side. And the friction ring plates 8c and 8d are clamped by the disks 8a and 8b, while the movable disk 8b is moved by the force of the spring 25 on the positive working clutch 9 side to the receiving disk 8a.
The friction ring plates 8c and 8d interposed between the disks 8a and 8b are separated from each other.

Accordingly, the connection between the clutch drum 6 and the positive working clutch 9 is cut off, and the planetary gear mechanism 7
The rotation transmitted to the clutch drum 6 is not transmitted to the clutch drum 6 through the positive operation clutch 9 but is directly transmitted to the clutch drum 6 without being decelerated through the negative operation clutch 8, and the small-diameter internal gear 17 and the intermediate gear 16 are transmitted from the clutch drum 6. Rotating casing via the output gear 15 and the eccentric oscillating type reduction mechanism 5
By rotating 1A, the asphalt finisher B runs at high speed. Further, by advancing the piston 2h in the cylinder chamber provided at the other end of the fixed casing 1B, the inclination of the swash plate 2g is reduced to reduce the pressure oil absorption amount per rotation of the hydraulic motor 2, and the same It is configured to rotate at a higher speed with the amount of hydraulic oil. In addition,
Instead of the eccentric oscillating reduction mechanism 5, an appropriate reduction mechanism such as a planetary gear mechanism may be employed.

Both rear wheels C of the asphalt finisher B,
The supply of pressure oil to the hydraulic motors 2 and 2 in the speed reducers A and A, which are directly connected to C, is performed through the third conduit 39 by driving the engine 31. The third conduit 39 is connected to the cylinders of the two hydraulic motors 2 and 2 via a flow dividing valve 40.
It has branch lines 39a and 39b for supplying pressure oil to the supply / discharge port of 2c and a switching valve 41 between these branch lines 39a and 39b.
Are connected and communicated with each other by a connecting pipe 42 having

In a normal construction and running state, the travel stop switch 43 and the speed changeover switch 44 are closed, but the solenoid 46 is excited because the changeover switch 45 of the changeover valve 41 is open. Without, therefore, the switching valve
When the vehicle travels in this state, the pressure oil is supplied to the branch pipes 39a and 39b in a 1: 1 amount by the flow dividing valve 40. When the vehicle travels straight, the two rear wheels C and C are the same. Demonstrate driving force by rotation. Further, when turning, a difference in rotation occurs between the hydraulic motors 2 and 2 on the rear wheels C and C. By adjusting the difference in rotation, that is, the difference in flow rate through the connecting pipe 42, an operation similar to that of the differential gear is performed. As a result, the two hydraulic motors 2 enable smooth running while maintaining the driving force.

When one of the rear wheels C spins and the switching valve 41 is in the open state as described above, the pressure oil intensively flows to the one rear wheel C and the two rear wheels C are rotated. In both cases, the driving force is lost. In order to prevent this, the changeover valve 41 is operated by closing the changeover switch 45 and exciting the solenoid 46, and the operation of the changeover valve 41 cuts off the communication between the branch pipe lines 39a and 39b, and the diverting valve. The pressure oil diverted 1: 1 by 40 flows into the respective hydraulic motors 2 and 2 of both rear wheels C and C to generate a driving force on the other rear wheel C, and pulls the asphalt finisher B as a differential lock mechanism. Is what you can do.

Next, when the engine 31 is turned off, the hydraulic pump 32
Then, the supply of the pressure oil to the pressure oil chamber 3f of the negative operation brake 3 in the speed reducer A through the first pressure oil passage 13 is stopped, and the pressure oil is also supplied to the second pressure oil passage 22 communicating with the negative operation clutch 8. Not supplied, and therefore the piston body of the negative actuation brake 3
3b is moved to the other side by the force of the spring 3e, and the friction ring plates 3e and 3h are sandwiched between the tip end surface of the small diameter portion of the piston body 3b and the vertical end surface of the small diameter portion of the cylinder portion 3a. Board 3
e, the hydraulic motor 2 is fixed by the frictional force of 3h.
B, the movable disk 8b is moved to the receiving disk 8a side by the force of the spring 19 on the negative operation clutch 8 side, and these disks 8a, 8b
Thus, the friction ring plates 8c and 8d are sandwiched, and the rotational force of the rotary casing 1A as the hub of the rear wheel C is braked by the negative operation clutch 8 and the negative operation brake 3.

Therefore, even if the asphalt finisher B turns off the engine 31 on the way of the slope and parks, the negative operation brake 3 works together with the negative operation clutch 8 to prevent the asphalt finisher from unexpectedly running away. Even if the engine 31 is operating, either the negative operating clutch 8 or the positive operating clutch 9 is frictionally connected unless the hydraulic oil is supplied to the negative operating brake 8, and the braking force of the negative operating brake 3 is reduced by the rear wheel. Since it is transmitted to C, safety can be ensured.

The wheel type asphalt finisher B sometimes travels on a general road as a general traveling vehicle. Therefore, the brake pedal 28 as a foot brake is required in the driver's seat like a general vehicle. When the negative operation brake 3 is employed as the actuator of the brake pedal 28, the braking performance may be deteriorated or damaged due to rapid braking. Therefore, the disc brake 27 is employed as described above. .

When a drum brake is used in place of the disc brake 27, the drum brake requires a long installation dimension in the axle direction. Therefore, in the asphalt finisher B, the width of the conveyor provided between the rear wheels is reduced. Since the carrying capacity of the pavement material and, consequently, the processing capacity of the asphalt finisher are reduced, a thin disc brake 27 is employed in the axle direction so that the conveyor capacity of the asphalt finisher is sufficiently exhibited.

When the driver depresses the brake pedal 28 to brake the vehicle with the disk brake 27 and the hydraulic motor 2 is in a running drive state, the brake exerts not only the inertia of the asphalt finisher body but also the running drive force. Braking must be performed, which increases the braking distance and makes it easier to cause an accident.However, as described above, when the brake pedal 28 is depressed, pressure oil is generated in the master cylinder 29 and the pressure switch 30 is released. When the pressure is detected, the relay 47 is activated and the relay switch 48 is opened, the excitation of the solenoid 35 is released, and the supply of the hydraulic oil to the hydraulic motor 2 is cut off. Contrary to 2, a braking force is generated to shorten the braking distance, thereby constituting a safer braking mechanism.

[0046]

As described above, according to the asphalt finisher traveling apparatus of the present invention, the rotary casings directly connected to these rear wheels as hubs for both rear wheels of the asphalt finisher and the frame side of the asphalt finisher. A fixed casing that is fixed and rotatably supports the rotary casing. The fixed casing incorporates a hydraulic motor and a negative operation brake that brakes the rotation of the hydraulic motor, while rotating integrally with the hydraulic motor. The rotation of the drive shaft can be transmitted to the rotary casing via one of a high-speed clutch provided in the rotary casing and a low-speed clutch connected to the reduction mechanism. When the asphalt finisher engine is stopped, the above negative operation is performed. Since the rotary casing is configured to be braked by the rake, the drive shaft is integrally formed by supplying hydraulic oil from a hydraulic pump operated by driving the asphalt finisher engine to the hydraulic motor and rotating the hydraulic motor. After rotation, the rotation is transmitted to the rotary casing via either the high-speed clutch or the low-speed clutch connected to the reduction mechanism, and the rear wheels can be directly driven to travel.

At this time, at the time of paving, the rotation of the drive shaft is decelerated by the speed reduction mechanism and transmitted to the rotary casing via the low-speed clutch, so that the rear wheels are rotationally driven at a vehicle speed and driving force suitable for paving. On the other hand, at the time of transportation or the like, the supply of pressure oil for clutch operation is shut off, and the rotation of the drive shaft is directly transmitted to the rotating casing via the high-speed clutch to rotate the rear wheel at high speed, The asphalt finisher can be run at a high speed suitable for transportation.

Further, when the supply of the pressure oil to the negative operation brake side is stopped, the rotational force of the rotary casing can be braked by the negative operation brake and the clutch, so that the asphalt finisher is moved on the slope. It is possible to prevent accidentally running away even if the vehicle is parked, and to eliminate the occurrence of an accident.

According to the second aspect of the present invention, the hydraulic oil supply line from the hydraulic pump operated by the engine is connected to the hydraulic motors for driving both rear wheels through the branch valve and the branch line. A differential lock mechanism that connects these branch lines with a connecting line equipped with a switching valve to perform differential lock and differential lock release is configured, so that during normal construction and traveling, the hydraulic oil supply line is connected to the branch line. It is possible to supply a flow rate corresponding to the rotation difference between the two rear wheels to the respective drive hydraulic motors of the two rear wheels via the flow dividing valve and the connection pipe to enable straight running or turning motion. When the wheel is spinned by a soft roadbed or the like, the connection pipe is closed by the switching valve provided in the connection pipe, so that the pressure oil diverted 1: 1 from the branch valves to both branch pipes. Supply each other To generate a traction drive force to the rear wheels, it is possible to reliably run an asphalt finisher.

Further, according to the third aspect of the present invention, since the disc brake which is operated by depressing the brake pedal of the driver's seat is mounted on the speed reducer directly connected to both rear wheels as hubs, the asphalt finisher is improved. Depressing the brake pedal from the driver's seat even during driving on a general road enables rapid braking that cannot be obtained by the above-mentioned negative operation brake, and enables safe driving.
In addition, since it is a disc brake, the distance between both rear wheels can be widened, so that the width of the pavement material provided between both rear wheels can inevitably be set to a wide width, and as an asphalt finisher Can fully demonstrate its conveyor capacity.

According to the fourth aspect of the invention, the pressure switch is operated by depressing the brake pedal, and the supply of the pressure oil to the rear wheel drive hydraulic motor is stopped by the electric signal. In addition, not only the driving force of the rear wheel by the hydraulic motor is cut off, but also the traveling braking force acts on the hydraulic motor, so that the braking distance of the asphalt finisher by the brake pedal is shortened, and the braking can be performed more safely and reliably.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a reduction gear transmission,

FIG. 2 is an enlarged longitudinal sectional side view of the hydraulic motor part,

FIG. 3 is an enlarged vertical sectional side view of a clutch side;

FIG. 4 is a side view of an asphalt finisher,

FIG. 5 is a cross-sectional view of the rear wheel,

FIG. 6 is a longitudinal sectional view thereof,

FIG. 7 is a circuit diagram between a brake pedal and a disc brake,

FIG. 8 is an electric circuit diagram,

FIG. 9 is a hydraulic circuit diagram,

FIG. 10 is a simplified perspective view showing a conventional example.

[Explanation of symbols]

 Reference Signs List A braking device B asphalt finisher C rear wheel 1A rotating casing 1B fixed casing 2 hydraulic motor 3 negative operation brake 4 drive shaft 5 eccentric oscillating reduction mechanism 6 clutch drum 7 planetary gear mechanism 8 negative operation clutch 9 positive operation clutch 13 first Pressure passage 22 Second pressure passage 27 Disc brake 28 Brake pedal 31 Engine 32 Hydraulic pump

Claims (4)

[Claims] 1. A rotary casing directly connected to the rear wheels as hubs of both rear wheels of an asphalt finisher, and a fixed casing fixed to a frame side of the asphalt finisher and rotatably supporting the rotary casing. The fixed casing has a built-in hydraulic motor and a negative operation brake that brakes the rotation of the hydraulic motor, while a drive shaft that rotates integrally with the hydraulic motor is extended toward the rotary casing and the drive shaft is A speed reduction device that enables transmission of the rotation to the rotation casing through one of a high speed clutch disposed in the rotation casing and a low speed clutch connected to the reduction mechanism is configured, and further, when the engine of the asphalt finisher is stopped. It is characterized in that the rotating casing is braked by the negative operation brake. Asphalt finisher traveling equipment to be characterized. 2. A hydraulic oil supply line from a hydraulic pump operated by an engine is connected to a hydraulic motor for driving both rear wheels through a branch valve and a branch line, and a switching valve is provided between these branch lines. The traveling device for an asphalt finisher according to claim 1, wherein a differential lock mechanism that performs differential lock and differential lock release by being connected by the provided connection conduit is configured. 3. The traveling device for an asphalt finisher according to claim 1, wherein a disc brake that is activated by depressing a brake pedal in a driver's seat is mounted on the reduction gear transmission. 4. A structure in which a pressure switch is provided in a brake circuit by a brake pedal, the pressure switch is operated by depressing the brake pedal, and the supply of pressure oil to the hydraulic motor is stopped by an electric signal of the pressure switch. The traveling device for an asphalt finisher according to claim 1 or 3, wherein: