JP2009185545A - Traveling device of self-propelling paving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling device capable of transmitting a stable drive force when drive wheels go into a skid inexpensively by a simple configuration in a wheel self-propelling paving machine driven by hydraulic motors. <P>SOLUTION: The wheel self-propelling paving machine is provided with: a hydraulic pump 11 driven by an engine 10; and the left and right hydraulic motors 12L, 12R for independently driving their respective left and right drive wheels 14L, 14R by the pressure oil discharged from the hydraulic pump 11. The paving machine is further provide with a selector valve 30 having: a first position (α) where the pressure oil from the hydraulic pump 11 is divided and supplied to and discharged from, the left and right hydraulic motors 12L, 12R; and a second position where the hydraulic oil from the hydraulic pump 11 is supplied to and discharged from the left and right hydraulic motors 12L, 12R in this order. The paving machine is also provided with a control section 40 for changing the selector valve 30 to the second position (β) when either of the left and right drive wheels 14L, 14R goes into a slip. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a traveling device in a self-propelled paving machine, and in particular, in a wheel-type self-propelled paving machine driven by a hydraulic motor, so that a stable driving force can be transmitted when a drive wheel slips. It is related with the traveling apparatus.

  Conventionally, as shown in FIG. 3, the traveling device of this type of wheel type self-propelled pavement machine includes a hydraulic pump 11 driven by an engine 10 and left and right rotating by pressure oil discharged from the hydraulic pump 11. The hydraulic motors 12L and 12R are provided, and the hydraulic oil from the hydraulic pump 11 is divided and supplied to the left and right hydraulic motors 12L and 12R. The left and right drive wheels 14L and 14R are respectively connected via the left and right drive shafts 13L and 13R. It is formed to be driven independently.

  In the above configuration, the pressure oil that has been divided into 1: 1 during normal straight travel is supplied to the left and right hydraulic motors 12L and 12R, so that the left and right drive wheels 14L and 14R rotate in the same direction. The flow rate to the left and right hydraulic motors 12L, 12R changes according to the rotation difference between 14L and 14R to adjust the rotation difference. However, when one drive wheel, for example, the right drive wheel 14R slips on a soft road surface or an uneven road surface, the load disappears and pressure oil flows intensively to the slipped hydraulic motor 12R, and the other hydraulic motor No pressure oil flows through 12L, and the driving force of the other driving wheel 14L is extremely reduced.

  In order to eliminate this problem, as shown in FIG. 4, brakes 15L and 15R for braking the left and right drive shafts 13L and 13R and brake cylinders 16L and 16R for operating the brakes 15L and 15R are provided. A traveling device for a self-propelled pavement machine formed so that the left and right drive shafts 13L and 13R can be braked independently via hydraulic lines 17L and 17R, which are separate systems from the hydraulic motors 12L and 12R, is known. (For example, refer to Patent Document 1).

  In the above-mentioned Patent Document 1, when any one of the driving wheels, for example, the right driving wheel 14R slips, the hydraulic oil in one hydraulic line 17R is pulled and slipped by a signal from a controller or an operator having appropriate detection means. The brake cylinder 16R on the side is actuated to brake the drive shaft 13R with the brake 15R. As a result, the idle rotation of the hydraulic motor 12R stops, the entire amount of pressure oil discharged from the hydraulic pump 11 flows to the other hydraulic motor 12L, and a driving force is generated on the other drive wheel 14L.

  In addition, the rotary casing is directly connected to both rear wheels, and the rotary casing is driven to rotate from the drive shaft via the high speed clutch or the low speed clutch connected to the speed reduction mechanism by the hydraulic motor built in the fixed casing. When the engine is stopped, the rotating force on the rotating casing side is braked by a negative operating brake with a built-in hydraulic motor in the fixed casing and the above clutch. An asphalt finisher traveling device is known that is configured to generate an traction force by supplying an equal amount of pressure oil to a hydraulic motor that rotationally drives a wheel (see, for example, Patent Document 2).

In Patent Document 2, a pressure oil supply line from a hydraulic pump is communicated with a hydraulic motor for both rear wheels through a diversion valve and a branch line, and a connection line having a switching valve is connected between these branch lines. When one of the rear wheels slips, a configuration is disclosed in which differential oil is operated by supplying pressure oil to the hydraulic motors of both rear wheels by operating the switching valve to shut off the connecting pipeline. ing.
JP 2001-32207 A Japanese Patent Laid-Open No. 2001-18670 (6th page, FIG. 9)

  In the invention described in Patent Document 1, when one of the drive wheels slips, the drive shaft on the slipped side is braked to lock one of the drive wheels, so that the vehicle travels with the drive force of only the other drive wheel. As a result, the driving force decreases. Further, since the drive wheel on the slipped side is locked and dragged, the running resistance against the road surface is increased, and the propulsive force of the vehicle body is further reduced.

  In the invention described in Patent Document 2, the diff lock mechanism is configured by the diversion valve and the switching valve provided in the connection circuit. However, the structure is complicated and causes a cost increase.

  Therefore, in a wheel-type self-propelled pavement machine driven by a hydraulic motor, a solution is provided in order to provide a traveling device capable of transmitting a stable driving force when a driving wheel slips with a simple configuration at low cost. The technical problem which should arise arises, and this invention aims at solving this problem.

  The present invention has been proposed to achieve the above object, and the invention according to claim 1 is characterized in that the hydraulic pump driven by the engine and the left and right drive wheels are respectively connected by the pressure oil discharged from the hydraulic pump. In a wheel-type self-propelled pavement machine having left and right hydraulic motors that are driven independently, a first position for distributing and supplying and discharging pressure oil from the hydraulic pump to the left and right hydraulic motors, and the hydraulic pump A switching valve having a second position for sequentially supplying and discharging pressure oil from and to the left and right hydraulic motors, and switching the switching valve to the second position when the left or right drive wheel slips. Provided is a traveling device in a self-propelled paving machine characterized by comprising a section.

  According to this configuration, when the vehicle normally travels, the switching valve is set to the first position. When the switching valve is in the first position, the pressure oil from the hydraulic pump is diverted to the left and right hydraulic motors, and when driving straight, the left and right drive wheels rotate in the same direction, and when turning, depending on the rotation difference between the left and right drive wheels The flow rate to the left and right hydraulic motors changes.

  On the other hand, when either the left or right drive wheel slips, the switching valve is switched to the second position by the detection of the detection means or the control of the control unit based on the instruction of the operator. When the switching valve is in the second position, the pressure oil from the hydraulic pump first flows to one of the left and right hydraulic motors, and then is sequentially supplied to and discharged from the other hydraulic motor to both the left and right hydraulic motors. The same amount of pressure oil is supplied and discharged. Therefore, both the left and right drive wheels are driven, and some driving force is generated on the slipped drive wheels.

  According to a second aspect of the present invention, the switching valve is disposed at a position where the suction side conduit of the left and right hydraulic motors and the discharge side conduit of the other hydraulic motor are shut off in a normal state. In the slip state, the pressure oil in the pipes on the discharge side of the other hydraulic motor is supplied to the suction side of the one hydraulic motor in the second position in the slip state. The traveling device for a self-propelled paving machine according to claim 1, wherein the traveling device is formed so as to communicate with the pipeline.

  According to this configuration, the switching valve is in the first position in the normal state, the pressure oil from the hydraulic pump is diverted, and one is a pipe on the suction side of one hydraulic motor through the first position of the switching valve. Pressure oil is supplied to the passage, the one hydraulic motor is driven, and returned to the hydraulic pump or the tank from the pipe line on the discharge side of the one hydraulic motor. The other one of the divided flow is supplied to the suction-side pipe line of the other hydraulic motor, drives the other hydraulic motor, and from the discharge-side pipe line of the other hydraulic motor, the first position of the switching valve. Is returned to the hydraulic pump or tank.

  In contrast, in the slip state, the switching valve is switched to the second position under the control of the control unit. When the switching valve is in the second position, the pressure oil from the hydraulic pump is first supplied to the suction side conduit of one hydraulic motor, and after driving the one hydraulic motor, the discharge side of one hydraulic motor It is discharged to the pipeline. This pressure oil is sent to the suction side conduit of the other hydraulic motor via the second position of the switching valve, and after driving the other hydraulic motor, from the discharge side conduit of the other hydraulic motor. Return to hydraulic pump or tank. Therefore, both the left and right drive wheels are driven, and some driving force is generated on the slipped drive wheels.

  According to the first aspect of the present invention, a switching valve having a first position and a second position is provided, and when either the left or right drive wheel slips, the switching valve is switched to the second position under the control of the control unit. Therefore, the pressure oil from the hydraulic pump is sequentially supplied to and discharged from the left and right hydraulic motors, and some driving force is generated also on the slipping drive wheels. Thus, the driving force can be increased at a low cost with a simple configuration as compared with the traveling device of the conventional self-propelled paving machine.

  According to the second aspect of the present invention, when one of the left and right drive wheels slips, the control valve controls the switching valve to the second position so that the suction side pipe line of one hydraulic motor and the other side are switched. Since the discharge side pipe line of the hydraulic motor is formed to communicate, the driving force can be increased more effectively in addition to the effect of the first aspect of the invention.

  Hereinafter, the traveling device in the self-propelled paving machine according to the present invention will be described with reference to preferred embodiments. In order to achieve the object of providing a traveling device capable of transmitting a stable driving force when a drive wheel slips in a wheel-type self-propelled paving machine driven by a hydraulic motor with a simple configuration at low cost. Further, the present invention provides a wheel-type self-propelled pavement provided with a hydraulic pump driven by an engine and left and right hydraulic motors that independently drive left and right drive wheels by pressure oil discharged from the hydraulic pump. In the machine, a first position for supplying and discharging pressure oil from the hydraulic pump to the left and right hydraulic motors, and a second position for sequentially supplying and discharging pressure oil from the hydraulic pump to the left and right hydraulic motors. When the left or right drive wheel slips, a control unit that switches the switching valve to the second position is provided.

  1 and 2 show a traveling device in a wheel-type self-propelled paving machine according to the present invention. For convenience of explanation, the same reference numerals are given to the same components as those of the conventional traveling device shown in FIGS. A duplicate description is omitted.

  As shown in FIG. 1, the discharge line 21 of the hydraulic pump branches from the middle into a suction side line 22L of the left hydraulic motor 12L and a suction side line 22 of the right hydraulic motor 12R. Further, the discharge side pipe 23L of the left hydraulic motor 12L and the discharge side pipe 23R of the right hydraulic motor 12R are coupled to the suction pipe 24 of the hydraulic pump from the middle.

  A switching valve 30 is interposed at a position where both the suction side pipeline 22L of the left hydraulic motor and the discharge side pipeline 23R of the right hydraulic motor are blocked. The switching valve 30 has a first position (A) for allowing the pressure oil in each of the suction side pipe line 22L of the left hydraulic motor and the discharge side pipe line 23R of the right hydraulic motor to pass, and the right valve And a second position (b) for communicating the pressure oil in the discharge side pipe line 23R of the hydraulic motor to the suction side pipe line 22L of the left hydraulic motor.

  A signal line 41 from the control unit 40 is connected to the solenoid 31 of the switching valve 30. In a normal state in which the solenoid 31 is not excited, the switching valve 30 is moved to the first position (a) by the bias of the spring 32. )It is in. Reference numeral 50 denotes a slip detection means for detecting the slip of the left or right drive wheel 14L, 14R. The slip detection means 50 is connected to the control unit 40 by a signal line 42.

  Next, the operation of the traveling device according to the present invention will be described. When traveling normally, as shown in FIG. 1, the solenoid 31 of the switching valve 30 is not excited, and the switching valve 30 is set to the first position (A).

  When the switching valve 30 is in the first position (A), the pressure oil from the hydraulic pump 11 passes through the discharge pipe 21, and in the middle, the suction side pipe 22L of the left hydraulic motor 12L and the right hydraulic motor 12R. Branches to the suction side pipe line 22. The pressure oil branched to the suction side pipeline 22L of the left hydraulic motor 12L is supplied to the left hydraulic motor 12L through the switching valve 30 through the first position (A), and rotates the left hydraulic motor 12L. After driving the left drive wheel 14L, the discharge side pipe 23L returns to the hydraulic pump suction pipe 24.

  Further, the pressure oil branched to the suction side pipe 22R of the right hydraulic motor 12R is supplied to the right hydraulic motor 12R as it is, and after rotating the right hydraulic motor 12R and driving the right drive wheel 14R, The switching valve 30 passes through the first position (A) from the discharge side pipe 23R and returns to the suction pipe 24 of the hydraulic pump.

  In this state, the pressure oil that has been divided into 1: 1 during normal straight travel is supplied to the left and right hydraulic motors 12L and 12R, so that the left and right drive wheels 14L and 14R rotate in the same direction. , 14R, the flow rate to the left and right hydraulic motors 12L, 12R changes to adjust the rotation difference.

  Here, when one drive wheel, for example, the right drive wheel 14R slips on a soft road surface or an uneven road surface, the load on the right drive wheel 14R disappears, the right hydraulic motor 12R runs idle, Pressure oil no longer flows through the hydraulic motor 12L, and the driving force of the left driving wheel 14L decreases.

  In the present invention, when the drive wheel slips, the detection means 50 detects the slip and sends a detection signal to the control unit 40. Upon receiving the detection signal, the control unit 40 sends a control signal to the solenoid 31 of the switching valve 30 to excite it, and switches the switching valve 30 to the second position (B). Alternatively, when the drive wheel slips, an operator may manually operate a switch (not shown) to excite the solenoid 31 and switch the switching valve 30 to the second position (B).

  As shown in FIG. 2, when the switching valve 30 is switched to the second position (b) under the control of the control unit 40 when the right drive wheel 14 </ b> R slips, the discharge pipe 21 and the discharge pipe 21 is disconnected from the suction side pipe line 22L of the left hydraulic motor 12L, and the discharge side pipe line 23R of the right hydraulic motor 12R and the suction side pipe line 22L of the left hydraulic motor 12L communicate with each other. To do.

  When the switching valve 30 is in the second position (b), the pressure oil from the hydraulic pump 11 passes through the discharge pipe 21 and is first supplied to the pipe 22R on the suction side of the right hydraulic motor 12R. The right hydraulic motor 12R is rotated to drive the right drive wheel 14R. Therefore, some driving force is also generated in the slipping right driving wheel 14R.

  Then, the pressure oil discharged to the discharge side pipe 23R of the right hydraulic motor 12R passes through the second position (B) of the switching valve 30 and is pressurized to the suction side pipe 22L of the left hydraulic motor 12L. Oil is supplied and the left hydraulic motor 12L is rotated to drive the left drive wheel 14L. The pressure oil discharged to the discharge line 23L of the left hydraulic motor 12L is returned to the hydraulic pump 11 or a tank (not shown) through the suction line 24.

  As described above, when one of the left and right drive wheels 14L and 14R slips, the left and right hydraulic motors 12L and 12R are connected in tandem by switching the switching valve 30 to the second position (B). Pressure oil flows through the left and right hydraulic motors 12L, 12R in turn. Accordingly, the left and right hydraulic motors 12L and 12R rotate substantially the same, and some driving force is generated on the slipping drive wheels.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

The circuit diagram of the traveling apparatus in the self-propelled pavement machine which concerns on this invention. The figure which shows the operation state of FIG. The circuit diagram of the traveling apparatus of the conventional self-propelled pavement machine. The circuit diagram of the traveling apparatus of the conventional self-propelled pavement machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine 11 Hydraulic pump 12L, 12R Hydraulic motor 14L, 14R Drive wheel 21 Discharge line 22L, 22R Suction side line 23L, 23R Discharge side line 24 Suction line 30 Switching valve (A) First position (B) First position 2 position 40 control unit 50 detection means

Claims (2)

In a wheel-type self-propelled pavement machine provided with a hydraulic pump driven by an engine and left and right hydraulic motors that independently drive left and right drive wheels by pressure oil discharged from the hydraulic pump,
A first position for distributing and supplying pressure oil from the hydraulic pump to the left and right hydraulic motors; and a second position for sequentially supplying and discharging pressure oil from the hydraulic pump to the left and right hydraulic motors. Provide a switching valve,
A traveling device in a self-propelled pavement machine, comprising a control unit that switches the switching valve to a second position when either of the left and right drive wheels slips.   The switching valve is disposed at a position where the suction-side pipe line of the left or right hydraulic motor and the discharge-side pipe line of the other hydraulic motor are cut off. In the slip state, the pressure oil in the discharge side pipe of the other hydraulic motor is communicated with the suction side pipe of the one hydraulic motor in the slip state. The traveling device for a self-propelled paving machine according to claim 1, wherein the traveling device is formed.

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