CN107228187B

CN107228187B - Transmission cut-off control device and method for construction machine

Info

Publication number: CN107228187B
Application number: CN201710166254.4A
Authority: CN
Inventors: 许连行
Original assignee: Doosan Infracore Co Ltd
Current assignee: Hyundai Yingweigao Co ltd
Priority date: 2016-03-23
Filing date: 2017-03-20
Publication date: 2020-01-14
Anticipated expiration: 2037-03-20
Also published as: DE202017001568U1; CN107228187A; KR20170110327A; KR102597075B1

Abstract

A transmission cut-off control device for a construction machine, comprising: a brake pressure detection unit for detecting a brake pressure; a boom position detecting unit for detecting a position of a boom; a vehicle speed detection section for detecting a vehicle speed; a vehicle control device for receiving the brake pressure, the boom-up position, and the vehicle speed, and outputting a cut-off control signal for performing a transmission cut-off operation based on the received values; and a transmission control device operatively connected to the vehicle control device and controlling a transmission cutoff operation in accordance with the cutoff control signal.

Description

Transmission cut-off control device and method for construction machine

Technical Field

The present invention relates to a transmission disconnection control device and method for construction machinery. More particularly, the present invention relates to a transmission disengagement control device for controlling a transmission disengagement operation of a construction machine and a transmission disengagement control method using the same.

Background

A work machine such as a wheel loader can perform a desired work by using both a running device and a working device. Such a construction machine may have a transmission cut-off function of automatically switching the transmission to a neutral state and maintaining the neutral state based on a brake pedal operation and an output of an engine or the like. In particular, when the front end working device is to be operated quickly in an operating state, an accelerator pedal (accelerator pedal) is depressed, and when operating power is connected, the operating speed is increased unintentionally, and a brake pedal is depressed at the same time in order to slow down the speed of the driven vehicle. In this case, the transmission cutoff operation is executed to cut off the operating power, thereby improving the efficiency of the operation.

However, when a loading operation is performed on a sloping field or on an automatic dump truck, if a brake pedal is stepped on, the running power is undesirably disconnected, which causes a shift shock and a running delay phenomenon, thereby causing a driver to have a discomfort that the on/off operation of the clutch cut-off switch must not be repeated.

Disclosure of Invention

Technical problem

The present invention addresses the problem of providing a transmission cut control device for a construction machine, which can establish neutral switching of a transmission at an optimum timing.

Another object of the present invention is to provide a method for controlling a transmission cutoff operation of a construction machine by using the transmission cutoff control device.

Technical scheme

To achieve the above object of the present invention, a transmission cut-off control apparatus for a construction machine according to some exemplary embodiments includes: a brake pressure detection unit for detecting a brake pressure; a boom position detecting unit for detecting a position of a boom; a vehicle speed detection section for detecting a vehicle speed; a vehicle control device for receiving the brake pressure, the boom-up position, and the vehicle speed, and outputting a cut-off control signal for performing a transmission cut-off operation based on the received values; and a transmission control device operatively connected to the vehicle control device and controlling a transmission cutoff operation in accordance with the cutoff control signal.

In some exemplary embodiments, optionally, the vehicle control device outputs the cut-off control signal to perform the transmission cut-off action when the brake pressure is greater than or equal to a reference pressure, the boom-up position is less than or equal to a set position, and the vehicle speed is greater than or equal to a set speed.

In some exemplary embodiments, optionally, the reference pressure of the brake pressure is 5bar, the set position of the boom-up position is a height of 40% of the entire height, and the set speed of the vehicle speed is 8 km/h.

In some exemplary embodiments, optionally, the transmission cut-off control apparatus further comprises: and the brake reference pressure setting switch is used for setting the reference pressure of the brake pressure.

In some exemplary embodiments, the reference pressure is optionally set between 15bar and 5bar by the brake reference pressure setting switch.

In some exemplary embodiments, optionally, the vehicle control device controls to stop the transmission cut-off operation when the received brake pressure is below a release reference pressure.

In some exemplary embodiments, optionally, the release reference pressure is 3 bar.

To achieve another object of the present invention, according to a transmission cut-off control method of a construction machine according to some exemplary embodiments, information on a brake pressure, a position of a boom, and a vehicle speed is obtained. An operation timing at which the transmission is turned off is decided based on the obtained information. It is possible to control to perform the transmission cut-off at the operation timing.

In some exemplary embodiments, optionally, when the operation timing of the transmission cut-off is determined, the operation timing is determined in such a manner that the transmission cut-off is performed when the brake pressure is greater than or equal to a reference pressure, the boom-up position is less than or equal to a set position, and the vehicle speed is greater than or equal to a set speed.

In some exemplary embodiments, optionally, the transmission cut-off control method includes the step of setting a reference pressure of the brake pressure.

In some exemplary embodiments, optionally, the reference pressure of the brake pressure is set between 15bar and 5bar when the reference pressure is set.

In some exemplary embodiments, optionally, the transmission cut-off control method further includes a step of controlling in such a manner that the transmission cut-off operation is stopped when the received brake pressure is below a release reference pressure.

ADVANTAGEOUS EFFECTS OF INVENTION

According to some exemplary embodiments, it is possible to maximize the effect of power cut and reduce the amount of axle heat generated by braking, compared to the conventional one, by reducing the conventional brake reference pressure in the transmission cut-off entry condition, and adding the boom position condition and the speed condition of the vehicle, thereby preventing the power cut-off control at the undesired time.

Therefore, the brake usage amount is greatly reduced, the heat productivity of the axle oil is reduced, and the power of the log is cut off, so that the energy loss of the engine is reduced, and the fuel efficiency is improved.

However, the effects of the present invention are not limited to the effects mentioned above, and various extensions may be made thereto without departing from the principle and scope of the present invention.

Drawings

Fig. 1 is a side view illustrating a wheel loader according to some exemplary embodiments.

Fig. 2 is a block diagram showing the transmission cut-off control apparatus of fig. 1.

Fig. 3 is a side view illustrating a boom-up position according to a rotation angle of the boom of fig. 1.

Fig. 4 is a graph showing some of the transmission cut-off operation sections determined by the transmission cut-off control apparatus of fig. 2.

FIG. 5 is a flowchart illustrating a transmission cut-off control method for a work machine, according to some exemplary embodiments.

Description of the symbols

10-wheel loader, 12-front truck, 14-rear truck, 20-boom, 22-boom cylinder, 24-boom angle sensor, 30-bucket, 32-bucket cylinder, 34-rocker, 36-bucket angle sensor, 40-cab, 50-engine room, 60-transmission, 70-front wheel, 72-rear wheel, 100-transmission cutoff control device, 102-clutch cutoff selection switch, 104-brake pressure setting switch, 110-brake pressure detection section, 120-boom position detection section, 130-vehicle speed detection section, 200-vehicle control device, 300-transmission control device.

Detailed Description

Specific structural and functional descriptions of the embodiments of the present invention that are not disclosed in the text are merely exemplary descriptions provided for illustrating the embodiments of the present invention, and the embodiments of the present invention may be embodied in various forms and should not be construed as limited to the embodiments described in the text.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood that it is not intended to limit the invention to the particular form disclosed, but rather to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms "first", "second", and the like may be used to describe various constituent elements, but the constituent elements are not limited to the terms. The terms may be used to distinguish one constituent element from other constituent elements. For example, a "first component" may be named a "second component", and similarly, a "second component" may also be named a "first component" without departing from the scope of the present invention.

When a certain component is referred to as being "connected" or "connected" to another component, it is to be understood that the component may be directly connected to the other component or may be connected to the other component, but other components may exist therebetween. In contrast, when a certain component is referred to as being "directly connected" or "directly connected" to another component, it is to be construed that no other component is present therebetween. Other expressions for explaining the relationship between the constituent elements, that is, "between … …", "between … …", or "adjacent to … …", "directly adjacent to … …", and the like should be interpreted as such.

The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless the context clearly dictates otherwise, singular expressions include plural expressions. In the present application, terms such as "comprising" or "having" should be interpreted as specifying the presence of the stated features, integers, steps, actions, elements, components, or groups thereof, but not preclude the presence or addition of one or more other features, integers, steps, actions, elements, components, or groups thereof.

Unless defined otherwise, such as technical or scientific terms, all terms used herein should be understood to have the same general meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Generally, terms such as those defined in dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in a tricky or exaggerated sense unless expressly defined herein.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and the repetitive description thereof will not be repeated for the same components.

Fig. 1 is a side view illustrating a wheel loader according to some exemplary embodiments. Fig. 2 is a block diagram showing the transmission cut-off control apparatus of fig. 1. Fig. 3 is a side view illustrating a boom-up position according to a rotation angle of the boom of fig. 1. Fig. 4 is a graph showing some of the transmission cut-off operation sections determined by the transmission cut-off control apparatus of fig. 2. In fig. 1, although a wheel loader 10 is illustrated, the transmission control device according to some exemplary embodiments cannot therefore be limited to be used only for a wheel loader, but may also be applied to an industrial vehicle such as a forklift. Hereinafter, for the convenience of explanation, only the wheel loader 10 will be described.

As will be appreciated with reference to fig. 1-4, a wheel loader 10 may include: a front vehicle body 12 and a rear vehicle body 14 rotatably coupled to each other. The front vehicle body 12 may include: working devices and front wheels 70. The rear vehicle body 14 may include: a cab 40, an engine compartment 50, and rear wheels 72.

The working device may include: a boom 20 and a bucket 30. The boom 20 is rotatably attached to the front vehicle body 12, and the bucket 30 is rotatably attached to one end of the boom 20. The boom 20 is connected to the front vehicle body 12 by a pair of boom cylinders 22, and the boom 20 can be rotated in the vertical direction by driving the boom cylinders 22. The swing arm 34 is attached to the center portion of the arm 20 so as to be rotatable, one end portion of the swing arm 34 is connected to the front vehicle body 12 via a pair of bucket cylinders 32, and the bucket 30 connected to the other end portion of the swing arm 34 via a tilt lever is rotatable (dumped or piled) in the vertical direction by driving the bucket cylinders 32.

The front vehicle body 12 and the rear vehicle body 14 are coupled to each other by a center pin 16 so as to be rotatable with respect to each other, and the front vehicle body 12 is bendable in the left and right directions with respect to the rear vehicle body 14 by extension and contraction of a steering cylinder (not shown).

The rear vehicle body 14 may mount a running device for running the wheel loader 10. The engine may be disposed within the nacelle 50 and provide a power output to the operating device. The running devices may include a torque converter, a transmission 60, a screw shaft, an axle, and the like. The power output of the engine is transmitted to the front wheels 70 and the rear wheels 72 through the torque converter, the transmission 60, the screw shaft, the axle, and the like to operate the wheel loader 10.

The transmission 60 may include a hydraulic clutch that shifts speed stages between a first speed and a fourth speed, and rotation of an output shaft of the torque converter may be shifted by the transmission 60. The transmission 60 may include a forward hydraulic clutch, a reverse hydraulic clutch, and first through fourth speed hydraulic clutches. Each of the hydraulic clutches may be engaged or disengaged by hydraulic oil (clutch hydraulic pressure) supplied from a Transmission Control Unit (TCU) 300. In other words, the hydraulic clutch may be engaged when the clutch hydraulic pressure supplied to the hydraulic clutch increases, and the hydraulic clutch may be disengaged when the clutch hydraulic pressure decreases.

When the driver intends to dump a load during the work piece transporting work, the wheel loader 10 may perform a transmission cut-off operation (transmission cut-off) for cutting off the operation power, after stepping on the accelerator pedal to quickly lift the boom, and stepping on the brake pedal to slow the vehicle speed. At this time, the vehicle control device (V CU) 200 outputs a control signal for executing a transmission cutoff operation to the transmission control device 300, and the transmission control device 300 cuts off the supply of the hydraulic oil to the forward/reverse hydraulic clutch so that the transmission is shifted to a neutral state. Next, a transmission cutoff control device that can control the transmission cutoff operation will be described.

As shown in fig. 2, the transmission cut-off control apparatus 100 of the construction machine may include: a brake pressure detection unit 110, a boom position detection unit 120, a vehicle speed detection unit 130, a vehicle control device 200, and a transmission control device (ECU). Further, the transmission cutoff control device 100 may further include a clutch cutoff selection switch 102. The driver can turn ON the clutch cut selection switch 102 to perform the transmission cut action, thereby improving the work efficiency and the fuel efficiency.

The brake pressure detecting unit 110 may detect information on the brake pressure. The brake pressure detecting part 110 may include: a brake pressure sensor for detecting a brake pressure or a brake pedal detection sensor for detecting an operation amount of a brake pedal. If the brake pedal detection sensor is provided, the operation amount of the brake pedal may be detected, and information on the brake pressure calculated based thereon may be provided.

The boom position detecting unit 120 may detect the position of the boom 20, that is, may detect information on the height of the boom from the ground. The boom position detecting part 120 may include a boom angle sensor 24 or a displacement sensor for detecting the position of the boom 20. The boom angle sensor 24 may detect a rotation angle of the boom 20 and provide information on the boom-up height based thereon.

As shown in fig. 3, the rotation angle of the boom 20 may be an angle between an extension line L at the lowest position (0%) of the boom 20 and an extension line of the boom 20. The rotation angle of the boom 20 at the maximum position (max boom height) of the boom 20 is θ max, and the boom-up position is the maximum height (100%). The rotation angle of the boom 20 at the farthest horizontal distance position (maximum horizontal reach) of the boom 20 is θ max.

The vehicle speed detection portion 130 may detect speed information of the vehicle. The vehicle speed detection portion 130 may include: a vehicle speed detection sensor that detects the rotational speed of the output shaft of the transmission 60, that is, detects the vehicle speed.

The vehicle control device 200 receives information on the brake pressure, the boom-up position, and the vehicle speed, and outputs a cut-off control signal for executing a transmission cut-off operation based on the received information.

Specifically, the vehicle control device 200 may determine the entry timing of the transmission cut-off operation. When the input signal matches an entry (entry) criterion in a state where the transmission cutoff function is enabled by the clutch cutoff selector switch 102, the vehicle control device 200 may determine an entry timing for executing the transmission cutoff operation. Specifically, the transmission cut-off operation may be controlled to be performed when the brake pressure is equal to or higher than a reference pressure, the boom-up position is equal to or lower than a set position, and the vehicle speed is equal to or higher than a set speed.

For example, the entering mode reference is a case where the brake pressure is equal to or higher than a reference pressure (5bar), the boom-up position is equal to or lower than 40% of the entire height, and the vehicle speed is equal to or higher than a set speed (1 st highest speed, for example, 8km/h), and the vehicle control device 200 may output a cut-off control signal for executing a transmission cut-off operation when the input signal matches the entering mode reference. The vehicle control device 200 may control the clutch cutoff operation using a power cutoff control algorithm as shown in table 1 below.

TABLE 1 Transmission control Algorithm

In table 1, condition 1 may be a case where the wheel loader is braked when the boom is at a low position during high-speed operation, condition 2 may be a case where the wheel loader is braked when excavating or moving up and down an incline in a low-speed operation during low-speed operation, and condition 3 may be a case where the wheel loader is lifted up and a loading operation is performed on an automatic dumping car during low-speed operation.

As shown in the control algorithm of table 1, the vehicle control device 200 can alleviate the entry condition to the brake pressure at a reference pressure of 5bar, which is less than 15bar in the related art, and determine the timing to shift the transmission to the neutral state in consideration of the signals for the boom-up position and the vehicle speed, so as to prevent the unnecessary interruption of the operation power when the dump operation is performed or on a sloping ground.

The transmission control device 300 is operatively coupled to the vehicle control device 200, and receives the clutch cutoff control signal, and cuts off the supply of the hydraulic oil to the forward/reverse hydraulic clutch at the determined entry time, so that the transmission 60 is shifted to a neutral state.

In some exemplary embodiments, the transmission cut-off control apparatus 100 may further include a brake reference pressure setting switch 104 for setting a reference pressure of the brake pressure. The driver can set the reference pressure of the brake pressure using the brake reference pressure setting switch 104. Thus, the reference pressure of the brake pressure may be set according to a user's selection, for example, to 5bar, 10bar, 15bar, and the like. Further, the transmission control device 100 may set the set position of the boom-up position and the set speed of the vehicle speed to values selected according to the intention of the driver.

Further, the vehicle control device 200 may control to stop the transmission cut operation when the input signal matches a release (disengagement) reference pressure in a state where the transmission cut operation is performed. For example, the vehicle control device 200 may set the condition for the brake pressure to the highest priority release condition, and may output a release control signal to stop the transmission cutoff operation when the input brake pressure is equal to or lower than a release reference pressure (for example, equal to or lower than 3 bar).

As shown in fig. 4, when the driver steps on the accelerator pedal for quickly raising the boom and then steps on the brake pedal for slowing down the vehicle speed while operating the dump truck at a high speed, the vehicle control device 200 may switch the transmission to the neutral state by disconnecting the transmission if the boom is between the lowest position and the farthest horizontal distance position and the vehicle speed satisfies the speed of 1 st gear or higher, and if a brake pressure of at least 5bar is input. Then, when the driver reaches the dump truck and removes his foot from the brake pedal, a brake pressure of 3bar or less is input, and the vehicle control device 200 may control to interrupt the transmission cutoff operation.

Next, a method of controlling a transmission cutoff operation of a construction machine will be described with reference to the transmission cutoff control device of fig. 2.

Referring to fig. 2 and 5, first, information on the brake pressure of the construction machine, the position of the boom, and the vehicle speed is obtained (S100).

For example, information on the brake pressure may be obtained by a brake pressure sensor or a brake pedal detection sensor. Information on the boom-up height may be obtained by a boom angle sensor or a displacement sensor. Information on the vehicle speed may be obtained by a vehicle speed detection sensor.

Next, the operation timing of the transmission cut-off is determined (S110), and the transmission cut-off operation is controlled to be executed at the determined operation timing (S120).

Specifically, in a state where the transmission cut-off operation is enabled (en able) by the clutch cut-off selector switch 102, when the input signal matches the entry criterion, the entry timing for executing the transmission cut-off operation can be determined. Specifically, for example, the transmission cut-off operation may be performed when the brake pressure is equal to or higher than a reference pressure, the boom-up position is equal to or lower than a set position, and the vehicle speed is equal to or higher than a set speed.

For example, the entry mode reference is a case where the brake pressure is equal to or higher than a reference pressure (5bar), the boom-up position is equal to or lower than 40% of the entire height, and the vehicle speed is equal to or higher than a set speed (1 st highest speed, for example, 8km/h), and the vehicle control device 200 may output a cut-off control signal for executing a transmission cut-off operation if the input signal matches the entry mode reference.

The entry condition of the brake pressure can be alleviated at a reference pressure of 5bar which is less than 15bar in the prior art, and the timing of shifting the transmission to the neutral state can be determined in consideration of signals of the boom-up position and the vehicle speed, so as to prevent unnecessary interruption of the operating power when a slope or a dumping operation is performed.

Then, the clutch cutoff control signal is received, and the supply of the hydraulic oil to the forward/reverse hydraulic clutch is cut off at the determined entry time, so that the transmission 60 is shifted to the neutral state.

In some exemplary embodiments, the reference pressure of the brake pressure may be set to a desired value. The driver can set the reference pressure of the brake pressure using the brake reference pressure setting switch 104. Thus, the reference pressure of the brake pressure may be set according to a user's selection, for example, to 5bar, 10bar, 15bar, and the like. Further, the set position of the boom-up position and the set speed of the vehicle speed may be set to values selected according to the intention of the driver.

In addition, in a state where the transmission cut operation is performed, if an input signal matches a release (disengagement) reference pressure, the transmission cut operation may be controlled to be stopped. For example, the condition for the brake pressure is set as the most priority release condition, and when the input brake pressure is equal to or lower than a release reference pressure (for example, 3bar or lower), a release control signal may be output to stop the transmission cut-off operation.

As described above, by alleviating the conventional brake reference pressure condition in the transmission cut-off entering condition and adding the boom position condition and the vehicle speed condition to prevent the power cut-off control at the unintended time, the effect of power cut-off is maximized as compared with the conventional one, and the amount of axle heat generated by braking can be reduced.

According to the transmission-cut control method, during normal operation of the wheel loader, the braking power is reduced by 3kW or more compared to the conventional one, so that the temperature of the axle can be reduced by about 15 ℃, and the fuel efficiency can be improved by reducing the engine energy loss.

While the foregoing has been with reference to certain embodiments of the invention, it will be understood that various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention as set forth in the following claims.

Claims

1. A transmission cut-off control device for a construction machine, comprising:

a brake pressure detection unit for detecting a brake pressure;

a boom position detecting unit for detecting a position of a boom;

a vehicle speed detection section for detecting a vehicle speed;

a brake reference pressure setting switch for setting a reference pressure of the brake pressure;

a vehicle control device for receiving the brake pressure, the boom-up position, and the vehicle speed, and outputting a cut-off control signal for performing a transmission cut-off operation based on the received values of the brake pressure, the boom-up position, and the vehicle speed; and

a transmission control device operatively connected to the vehicle control device and controlling a transmission cutoff operation based on the cutoff control signal,

setting a condition for brake pressure as a most-priority release condition, the vehicle control device controlling to stop the transmission cut-off operation when the received brake pressure is a release reference pressure or less,

the release reference pressure is lower than a reference pressure of the brake pressure.

2. The transmission cut-off control apparatus for a construction machine according to claim 1,

the vehicle control device outputs the cut-off control signal to execute the transmission cut-off operation when the brake pressure is equal to or higher than a reference pressure, the boom-up position is equal to or lower than a set position, and the vehicle speed is equal to or higher than a set speed.

3. The transmission cut-off control apparatus for a construction machine according to claim 2,

the reference pressure of the brake pressure is 5bar, the set position of the boom-up position is a height of 40% of the overall height, and the set speed of the vehicle speed is 8 km/h.

4. The transmission cut-off control apparatus for a construction machine according to claim 1,

the reference pressure is set between 15bar and 5bar by the brake reference pressure setting switch.

5. A transmission cut-off control method for a construction machine, comprising:

obtaining information on a brake pressure, a position of a boom, and a vehicle speed;

setting a reference pressure of the brake pressure;

a step of determining an operation timing at which the transmission is turned off based on the obtained information; and

control to execute a transmission cut-off step at the operation timing,

control such that the step of performing transmission cut-off at the operation timing includes:

setting a condition for a brake pressure to a most-priority release condition, controlling to stop the transmission cut-off operation when the obtained brake pressure is equal to or lower than a release reference pressure,

6. The transmission cut-off control method of a construction machine according to claim 5,

when the operation timing of the transmission cut-off is determined, the operation timing is determined such that the transmission cut-off is executed when the brake pressure is equal to or higher than a reference pressure, the boom-up position is equal to or lower than a set position, and the vehicle speed is equal to or higher than a set speed.

7. The transmission cut-off control method of a construction machine according to claim 5,

8. The transmission cut-off control method of a construction machine according to claim 5,

setting the reference pressure of the brake pressure between 15bar and 5 bar.