KR100255220B1 - Retarding torque change control device - Google Patents

Abstract

PURPOSE: A variable controller for the retarding torque of a traveling motor is provided to reduce retarding torque when an accelerator pedal is released during a first gear traveling and to increase retarding torque when the accelerator pedal is released during a second gear traveling. CONSTITUTION: A variable retarding torque controller for a traveling motor(4) comprises a main pump(1); the traveling motor; a speed change device(14) transmitting the rotation of the traveling motor to the wheels of an excavator after changing speed in multistage; a control valve(2) switching the direction of compressed oil supplied from the main pump to the traveling motor; and a pair of operating lines(9) hydraulically connecting the control valve and the traveling motor as a feeder and a discharger. When a gear lever(12) is in a first lever and an accelerator pedal is released, pilot compressed oil is not transmitted to a shuttle valve(16) and a main line. Then, the pressure of the shuttle valve is suddenly lowered and a second geared variable relief valve(10) is not affected. When the gear lever is in a second lever and the accelerator pedal is released, the pressure of a pilot line is suddenly lowered but pressure in a second gear shift line(15) is continuously kept and the relief pressure of the second geared variable relief valve is set higher than during the first gear traveling. Therefore, the retarding torque of the traveling motor is in the same level while driving a first geared speed change device or a second geared speed change device.

Description

Driving motor retarding torque variable control device of wheel type heavy equipment

The present invention relates to a variable driving motor retarding torque variable control device of a wheel type heavy equipment, in particular, when the accelerator pedal is released in the first gear shifting state and the second gear shifting state of the driving motor, the retarding torque is lowered smoothly. A driving motor retarding torque variable control device for a wheel type heavy machinery that enables a driving state to be achieved.

In general, in a wheel type heavy equipment that uses hydraulic pressure as a power source, as shown in FIG. 3, the driving force is generated using the traveling motor 101 which is hydraulically operated, and the driving force of the traveling motor 101 is shown. Is transmitted to the drive shaft 103 of the heavy equipment through the transmission (102).

The traveling motor 101 is discharged from the main pump 104 to be driven by pressure oil supplied through the control valve 105 and the count balance valve 106, and the transmission device 102 is an auxiliary pump. It is to be selected in one or two stages by the pilot pressure oil discharged from 107 and transmitted through the 1,2-stage shift valve 108.

On the other hand, the count balance valve 106 to throttle the pressure oil discharged from the traveling motor 101 when the control valve 105 is in a neutral state so as to generate a braking force of the vehicle as the traveling motor 101 body When the driver releases the accelerator pedal (not shown) while the vehicle is running, the control valve 105 is switched to a neutral position, and at this time, the hydraulic pressure of the main line 107 discharged from the main pump 104 is provided. The count balance valve 106, which is operated by receiving the pilot pressure, is also switched to a neutral state, so that the discharge side flow path of the traveling motor 101 is suppressed to generate the braking force of the vehicle as the traveling motor 101 body. do.

Therefore, the pressure of the hydraulic oil supplied to the traveling motor 101 to rotate the rotor therein and discharged is instantly switched to high pressure. At this time, the pressure oil of the high pressure is the count balance valve 106 and the traveling motor 101. Drain to the oil tank through the relief valve (110, 111) respectively installed in the operation line (109) for connecting between.

Therefore, the discharge side pressure of the traveling motor 101 is to be determined according to the set pressure of the relief valve (110, 111).

On the other hand, due to the high back pressure generated on the discharge side of the traveling motor 101 instantaneously when the accelerator pedal is released as described above, a retarding torque for stopping rotation of the traveling motor 101 is applied. Will slow down the machine.

In other words, when the driver releases the accelerator pedal, no additional hydraulic oil is supplied to the driving motor to generate acceleration force, and retarding torque is generated to prevent rotation of the driving motor, thereby preventing overrun of the machine. There is also the advantage of extending the life of the brake discs, but the problem of undesirably slowing down the machine has been raised.

In addition, in the conventional apparatus as described above, the retarding torque of the hydraulic motor 101 is generated with a large difference according to the transmission gear selected by the transmission device 102 by switching of the transmission valve 108.

For example, since the first gear reduction ratio of the transmission 102 is greater than the second gear reduction ratio (in the case of an excavator, the first gear reduction ratio i1: the second gear reduction ratio i2 = 4). When the retarding torque is located in the first stage, the retarding torque is about four times larger than the retarding torque in the second stage.

Arithmetic representation of this,

T1 = P X q / 200π x i1 (Retarding torque in 1 stage) ---- (1)

T2 = P X q / 200π x i2 (Retarding torque in 2 stages) ---- (2)

Becomes

here,

T (kgm): Retarding torque of motor

q (cc / rev): Motor volume (displacement)

P: relief pressure of motor

i1: Gearbox 1 gear ratio

i2: Gear ratio 2 gear ratio.

Since i1 / i2 = 4 above,

Eventually, T1 / T2 = 4.

∴ 1st stage torque is 4 times higher than 2nd stage.

The inlet and outlet pressure change curves of the traveling motor during acceleration and deceleration driving of the conventional wheel type heavy equipment as shown above are shown in FIG. 4. That is, if the accelerator pedal is released while driving at constant speed, the hydraulic pressure supplied from the main pump is cut off by the control valve, and the equipment is rapidly decelerated. That is, while the hydraulic pressure supplied from the main pump is cut off, the inlet pressure of the traveling motor 101 is suddenly lowered, while the outlet pressure of the traveling motor 101 is in a high pressure state due to the inertia of the equipment. This outlet pressure acts as a back pressure, which ultimately increases the retarding torque of the traveling motor.

For this reason, if the driver releases the accelerator pedal in a hurry, the decelerating shock is bad for the driver because the machine is suddenly decelerated in a crying state.

On the other hand, in order to solve such a problem, the retarding torque should be reduced, and as the easiest method of the solution, a method of lowering the set pressure of the steel relief valves 110 and 111 can be devised.

However, when the set pressure of the relief valves 110 and 111 is unconditionally reduced, the retarding torque is too small in the second stage, and there is a problem of overrunning the equipment when the accelerator pedal is released. That is, there is a problem that the retarding torque cannot be exerted in the second stage.

In order to solve the above problems, the present invention reduces the retarding torque when releasing the accelerator pedal during the first stage of operation in a wheel type heavy equipment employing a hydraulically driven traveling system, and releases the accelerator pedal during the second stage of the driving. The purpose of the present invention is to provide a driving motor retarding torque variable device of a wheel type heavy equipment which can increase the retarding torque.

The present invention for achieving the above object, the main pump, a traveling motor that is supplied with the pressure oil from the main pump to rotate, and a transmission for transmitting to the wheels of the excavator by shifting the rotation of the traveling motor in multiple stages; . A control valve for switching the direction of the hydraulic oil supplied from the main pump to the driving motor, hydraulically connecting the control valve and the driving motor, and a pair of operation lines at which one is a discharge side and the other is a discharge side; In the hydraulic motor of the drive-type motor of the wheel type heavy equipment having a pair of relief valves connected to the respective operation lines to open when the oil pressure of the operation line is higher than a predetermined pressure, a shift signal applied to the transmission device And a variable relief valve means for boosting the relief pressure of the operation line when the shift signal detected by the shift signal detection means is at least two stages. Pump pressure detecting means for detecting the pressurized oil supplied from the pump to the traveling motor, and the pump pressure detecting means The emitter detected pressure oil to the variable release configuration in which further connected to the pipe valve means is characterized.

On the other hand, the pump pressure detecting means is composed of a shuttle valve connected at both ends to a pair of main lines connecting the control valve and the count balance valve, and the pressure oil detected from the pump pressure detecting means and the shift signal detecting means is a shuttle It is connected so as to flow into both ends of the valve, the high pressure pressure of any one of the introduced pressure oil is connected to the variable relief valve means through a pilot line, the shift signal detecting means is a transmission device in the speed change valve It consists of a shuttle valve that detects oil pressure from the two-speed line connected with The variable relief valve means may be provided with a spring and a control mechanism on one side of the hydraulic pressure portion to determine the relief pressure of the operation line in response to the pressure of the operation line, wherein the control mechanism detects the pump pressure in addition to the spring. It consists of a two-stage variable relief valve connected to the pilot line, which is the oil pressure line detected from the means or the shift signal detecting means.

In the apparatus of the present invention having such a structure, when driving in the state of shifting to the first stage and releasing the accelerator pedal, the driving motor control valve is switched to neutral so that the traveling hydraulic pressure supplied from the main pump is cut off. Since the pilot pressure generated through the shuttle valve installed in the line is not generated, the two-stage variable relief valve is adjusted to a low pressure state which is an initial spring pressure.

On the other hand, if the accelerator pedal is released while driving the gearbox in two stages, the pilot pressure generated through the shuttle valve installed on the main line is not generated, but the signal oil pressure of the two-speed line from the gearbox to the gearbox is maintained. The signal hydraulic pressure provided from the two-speed transmission line is transmitted to the control mechanism installed at one hydraulic pressure section of the two-stage variable relief valve through the shuttle valve and the pilot line, and together with the spring of the two-stage variable relief valve. It will boost the relief pressure.

Therefore, when releasing the accelerator pedal in the first stage driving state, the set pressure of the two-stage variable relief valve is maintained at a low state, and as a result, the back pressure of the traveling motor is lowered so that the retarding torque is lower than that of the transmission gear ratio. When the accelerator pedal is released in the two-stage driving state, the set pressure of the two-stage variable relief valve is maintained high, so that the back pressure of the traveling motor is increased, so that the retarding torque is increased in the transmission gear ratio.

As a result, when the accelerator pedal is released in the 1st or 2nd shift state, the equipment suddenly brakes and the phenomena of stopping and stopping are reduced to a very good state.In the 2nd shift state, the braking effect is caused by the retarding torque. Will increase.

1 is a hydraulic circuit diagram showing a drive motor retarding torque variable control apparatus for heavy equipment according to the present invention.

2 is a plot of the change in retarding torque with respect to time exhibited when using the device according to the invention.

3 is a hydraulic circuit diagram showing a traveling motor retarding torque variable control device used in a conventional wheel type heavy equipment.

FIG. 4 is a change diagram of retarding torque with respect to time appearing when using the apparatus shown in FIG.

* Explanation of symbols for main parts of the drawings

1: main pump 2: control valve

3: count balance valve 4: drive motor

5: main line 6: shuttle valve

7: pilot line 8: swash plate angle control mechanism

9 operating line 10 variable relief valve means

10a: spring 11: auxiliary pump

12 shift valve 13 drive shaft

14: transmission 15: two-speed line

16: Relief control shuttle valve 17: Pilot line

18: control mechanism

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

1 is a hydraulic circuit diagram showing a device according to the present invention. As shown in this figure, the device of the present invention is a main motor 1 and a traveling motor that is supplied with hydraulic oil from the main pump 1 and rotates. (4), the transmission 14 for shifting the rotation of the traveling motor 4 in multiple stages and transmitting the wheels of the excavator, and the direction of the hydraulic oil supplied from the main pump 1 to the traveling motor 4; Hydraulically connects the control valve 2 to be switched, and the control valve 2 and the traveling motor 4, and has a pair of operation lines 9 on which the other side becomes the discharge side when one side becomes the supply side. Doing.

The apparatus according to the present invention further comprises shifting signal detecting means for detecting a shifting signal applied to the shifting device 14 and the operation line 9 when the shifting signal detected by the shifting signal detecting means is at least two-stage signals. And a variable relief valve means for boosting the relief pressure of the pump, the pump pressure detecting means for detecting the hydraulic oil supplied from the main pump 1 to the traveling motor 4, and the pump pressure detecting means. Pressure oil detected from the connection is further configured to the variable relief valve (10).

On the other hand, the pump pressure detecting means is composed of a shuttle valve (6) connected at both ends to a pair of main lines (5) connecting the control valve (2) and the count balance valve (3), the pump pressure detection The oil pressure detected from the means and the shift signal detecting means is connected to both ends of the other shuttle valve 16, respectively, and the high pressure oil of any one of the introduced pressure oils is changed through the pilot line 17. It is connected to the relief valve means 10, the shift signal detecting means is composed of a shuttle valve 16 for detecting the pressure oil from the two-speed transmission line 15 connected from the shift valve 12 to the transmission.

And the variable relief valve means 10 together with the spring (10a) and the control mechanism 18 in one hydraulic pressure unit to determine the relief pressure of the actuation line (9) in response to the pressure of the actuation line (9) Install. The control mechanism 18 is connected to the pilot line 17 which is a hydraulic oil line detected from the pump pressure detecting means or the shift signal detecting means in addition to the spring 10a.

The operation of the apparatus of the present invention having the structure as described above will be described below.

In the device of the present invention, the driving motor 4 is driven by the hydraulic oil supplied from the main pump 1, and the configuration of this part is the same as that of the conventional device, so as to avoid repeated explanation. Omitted, only the following will describe the operation process for a specific component of the present invention.

First, when the shift lever 12 is switched to the first position and the shift device 14 is shifted to the first stage, the accelerator pedal is discharged from the auxiliary pump 11 when the accelerator pedal is released. In the first stage state is not delivered to the shuttle valve 16, since the control valve (2) is in a neutral state because the hydraulic oil is not supplied to the main line (5), the shuttle valve located on the main line (5) Hydraulic pressure does not occur in (6), and accordingly, the pressure of the pilot line 7 is not generated, and thus, the pressure is suddenly lowered in the shuttle valve 16, so that there is no influence on the two-stage variable relief valve 10. Will not give. Therefore, the two-stage variable relief valve 10 reliefs the pressure oil discharged from the traveling motor 4 according to the set pressure set by the spring 10a.

On the other hand, in the state in which the shift lever 12 is switched to the two-stage state so that the pilot pressure discharged from the auxiliary pump 11 is transmitted to the transmission device 14 through the two-speed line 15, the driver accelerates. When the pedal is released, that is, when the control valve 2 is switched to the neutral state, the pressure of the pilot line 7 generated through the shuttle valve 6 is drastically lowered, but the Since the pressure is continuously maintained, the pressure is transmitted to the shuttle valve 16, and the pressure oil supplied through the shuttle valve 16 is connected to the two stage variable relief valve 10 through the pilot line 17. To the control mechanism 18. Therefore, the control mechanism 18 receiving the high pressure oil sets the relief pressure of the two-stage variable relief valve 10 together with the spring 10a to a higher pressure when releasing the accelerator pedal during the first stage of travel.

As a result, the retarding torque T2 of the traveling motor 4 which drives the transmission 14 of the two-stage state by which the reduction ratio i2 is about four times smaller than that of the first stage is expressed by Equations 1 and 2 above. It is to be maintained at the same level as the retarding torque (T1) of the traveling motor 4 for driving the transmission in the short state.

2 shows a change diagram of the inlet pressure and the outlet pressure of the traveling motor during acceleration and deceleration in the case of a wheel-type heavy equipment to which the driving motor retarding torque variable control device according to the present invention is applied.

That is, as shown in FIG. 2, when the set pressure of the first stage and the set pressure of the second stage are about 1/3, the retarding torque generated in the deceleration section of the traveling motor 4 is TX 4 (1 , The second gear ratio) X 1/3 (single motor reduction torque compared to the second stage), so that the retarding torque in the first stage and the retarding torque in the second stage are similarly controlled.

On the other hand, while driving in the first stage or the second stage, that is, when the driver is stepping on the accelerator pedal, the two stage variable relief valve 10 is provided with the hydraulic pressure on the main line 5 or the second stage through the shuttle valve 16. Since one of the hydraulic pressure on the transmission line 15 is continuously supplied, the two-stage variable relief valve 10 maintains a set pressure higher than a predetermined pressure, thereby maintaining the function of the conventional driving motor.

As described above, according to the device according to the present invention, when releasing the accelerator pedal in the first stage driving state, the set pressure of the two-stage variable relief valve is maintained at a low state, and as a result, the back pressure of the traveling motor is lowered so that the Rita The ding torque is lower than that of the transmission gear ratio, and when the accelerator pedal is released in the two-stage driving state, the set pressure of the two-stage variable relief valve is kept high, so that the back pressure of the driving motor is increased so that the retarding torque becomes higher in the transmission gear ratio. do.

As a result, when releasing the accelerator pedal in the 1st or 2nd shifting state, the equipment is suddenly braked and there is no sudden and sudden deceleration, resulting in a very smooth running state.In the 2nd shifting state, the retarding torque It will increase the braking effect.

Claims (6)

Main pump (1), the traveling motor (4) is rotated by receiving the pressure oil from the main pump (1), and the transmission for transmitting to the wheels of the excavator by shifting the rotation of the traveling motor (4) ( 14) and a control valve 2 for switching the direction of the hydraulic oil supplied from the main pump 1 to the driving motor 4, and hydraulically connecting the control valve 2 and the driving motor 4; When one side is the supply side, the other side is connected to a pair of operation line 9 and the respective operation line 9 to be opened when the pressure oil of the operation line 8 is above a predetermined pressure A traveling motor hydraulic circuit of a wheel type heavy equipment having a pair of relief valves installed, the shifting motor detecting circuit further comprising a shift signal detecting means for detecting a shift signal applied to the transmission device 14, wherein the relief valve includes: The shift signal detected by the signal detecting means is at least two or more steps Foil when the variable relief variable retarding torque control apparatus for a wheel type heavy equipment, characterized in that the valve means (10) for boosting the relief pressure of the operating line (9). According to claim 1, further comprising a pump pressure detecting means for detecting the pressure oil supplied from the main pump (1) to the traveling motor (4), the pump pressure detecting means is the variable relief valve means (10) Retarding torque variable control device of the wheel type heavy equipment, characterized in that further connected to the variable relief valve means (10) to control. 3. The wheel according to claim 2, wherein the pump pressure detecting means is a shuttle valve (6) connected at both ends to a pair of main lines (5) connecting the control valve (2) and the count balance valve (3). Variable retarding torque control device of type heavy equipment. 3. The pump according to claim 2, further comprising a shuttle valve (16) for selecting a high pressure hydraulic oil in the hydraulic oil detected by said pump pressure detecting means and said shift signal detecting means, wherein the outlet of said shuttle valve (16) is a pilot. Retarding torque variable control device of the wheel type heavy equipment, characterized in that connected to the variable relief valve means (10) via a line (17). 2. The wheel type according to claim 1, wherein the shift signal detecting means is a shuttle valve (16) for detecting hydraulic oil from a two-speed transmission line (15) connected from the shift valve (12) to the shift device (14). Variable retarding torque control device for heavy equipment. 2. The variable relief valve means (10) according to claim 1, wherein the variable relief valve means (10) has a spring (10a) and a control mechanism on one side of the hydraulic pressure unit to determine the relief pressure of the actuation line (9) in response to the pressure of the actuation line (9). (18), the control mechanism (18) is a two-stage variable connected to a pilot line (17) which is a pressure oil line detected from the pump pressure detecting means or the shift signal detecting means in addition to the spring (10a). Retarding torque variable control device of wheel type heavy equipment, characterized in that the relief valve (10).