JP2012031635A - Interference prevention device of working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate computing a control of a interference prevention device in a working machine equipped with an elevating cab and a multi-joint operation arm.SOLUTION: Movement of an operation arm is restricted based on an arcuate restricted area (LMN) or a linear restricted area (PQHIMN) which are restricted areas determined in advance based on the lowermost and uppermost positions of a cab.

Description

  The present invention relates to an interference prevention device for a work machine, and more particularly to an interference prevention device for a cab and a work arm of a work machine having a lifting cab and an articulated work arm.

  There is a working machine such as a hydraulic excavator provided with a cab that is freely attached to raise and lower and an articulated work arm that is freely attached to swing in the vertical direction. The cab is raised and lowered by the expansion and contraction of the lifting and lowering hydraulic cylinder, and can be adjusted to a height corresponding to the work. The work arm includes a boom that is swingably attached to the machine body, and an arm that is swingably attached to the tip of the boom, and a work attachment is attached to the tip of the arm.

  The working machine including the lifting cab and the work arm is provided with an interference prevention device for preventing interference between the cab and the tip of the work arm (for example, see Patent Document 1). This interference prevention device detects the refraction state of the multi-joint work arm to determine the position of the arm tip, and detects the cab's lift position to correct the limit area that limits the work arm's movement according to the lift position. , Interference prevention control between the work arm and cab is performed.

JP-A-8-35239 (FIGS. 1 to 8)

  The work implement interference prevention apparatus as described above has the following problems to be solved.

  That is, since this interference prevention device detects the position of the lift cab, corrects the restriction area, and performs interference prevention control, the control calculation is complicated. In addition, since the operation of the boom and the arm of the work arm is restricted at the same time, workability is deteriorated.

  The present invention has been made in view of the above facts, and a main technical problem thereof is to simplify the control calculation of the interference prevention device in a work machine including a lifting cab and a multi-joint work arm. Another technical problem is to improve deterioration in workability due to simultaneous restriction of the operation of the boom and arm of the work arm in a working machine including a lifting cab and a multi-joint work arm.

  According to the present invention, in order to solve the above-mentioned main technical problem, a working machine comprising a cab that is freely mounted for lifting and lowering and an articulated work arm that is freely mounted for swinging in the vertical direction. A device for preventing interference between the cab and the front end of the work arm located in front of the cab, characterized in that the movement of the work arm is limited based on a preset limit range depending on the lowest position and the highest position of the cab. An interference prevention device for a working machine is provided.

  As the restriction area, an arc-shaped restriction area provided along an arc-shaped locus in which the cab moves up and down is provided.

  As another example of the restriction area, a linear restriction area provided along a straight line connecting the lowest position of the cab and the front face of the highest position is provided.

  In a preferred embodiment, as the restriction area, an arc-shaped restriction area provided along an arcuate locus in which the cab is raised and lowered, which is selectively switched by a changeover switch, and a lowermost position of the cab and a front face at the uppermost position are connected. A linear restriction area provided along a straight line is provided.

  In order to solve other technical problems, the work arm includes a boom that is freely swingable in the vertical direction on the machine body and an arm that is freely swingable in the vertical direction on the tip of the boom. The interference prevention device includes a boom angle sensor that detects a swing angle of the boom with respect to the body, an arm angle sensor that detects a swing angle of the arm with respect to the boom, and an output of the boom angle sensor and the arm angle sensor. And a controller for calculating the position of the tip and individually restricting the boom raising operation and the arm lowering operation based on the restriction region.

  The interference prevention device for a work machine configured according to the present invention restricts the movement of the work arm based on a preset limit range depending on the lowest position and the highest position of the cab. Further, the boom raising operation and the arm lowering operation of the work arm are individually restricted.

  Accordingly, since the movement of the work arm is limited based on the preset limit range without detecting the position of the lifting cab and correcting the limit range, the control calculation of the interference prevention device can be simplified. . Further, since the boom raising operation and the arm lowering operation of the work arm are individually restricted, it is possible to improve the deterioration of workability due to the simultaneous restriction of the operation of the boom and the arm.

The side view of the working machine provided with the interference prevention apparatus of a raising / lowering cab and a working arm. BRIEF DESCRIPTION OF THE DRAWINGS FIG. The attachment figure of the angle sensor of an interference prevention device. The hydraulic system figure of a working machine. Explanatory drawing of an interference prevention restriction area. Explanatory drawing of the controller of an interference prevention apparatus. Explanatory drawing of the boom limit angle. FIG. 6 is a diagram for explaining calculation of an arm limit angle. Explanatory drawing of the boom limit angle. FIG. 6 is a diagram for explaining calculation of an arm limit angle.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a working machine interference preventing apparatus constructed according to the present invention will be described in more detail with reference to the accompanying drawings illustrating preferred embodiments.

  With reference to FIG. 1, the working machine provided with the raising / lowering cab and the articulated work arm is demonstrated. The work machine generally designated by reference numeral 40 includes a lower traveling body 1, an upper swing body 2 mounted on the lower traveling body 1, a cab 8 that is freely mounted on the upper swing body 2 and capable of moving up and down, and a vertical direction. Is provided with a work arm 3 which is freely mounted for swinging operation.

  The cab 8 is attached to the support 7 of the upper swing body 2 via a pair of parallel links 9 and 10 and a cab elevating hydraulic cylinder 11 that moves the links 9 and 10 up and down. The cab 8 can be moved up and down by expanding and contracting the hydraulic cylinder 11, and the cab 8 can be adjusted to a height corresponding to the work between the lowermost position (shown by a solid line) and the uppermost position (shown by a two-dot chain line). .

  The work arm 3 includes a boom 4 attached to the upper swing body 2 so as to be swingable in the vertical direction, and an arm 5 attached to the tip of the boom 4 so as to be swingable in the vertical direction. Attachment 6 is attached. A boom operating hydraulic cylinder 4 a is attached between the upper swing body 2 and the boom 4, and an arm operating hydraulic cylinder 5 a is attached between the boom 4 and the arm 5.

  The work machine 40 restricts the movement of the work arm 3 based on the “restricted area” set in advance by the lowest position and the highest position of the cab 8, and the work arm 3 is positioned in front of the cab 8 and the cab 8. An interference prevention device for preventing interference with the unit.

  The outline of the interference preventing apparatus will be described with reference to FIG. 2 together with FIG. The interference prevention device 50 includes a boom angle sensor 12 that detects a swing angle of the boom with respect to the upper swing body 2 that is a body, and an arm angle sensor 13 that detects a swing angle of the arm 5 with respect to the boom 4. 12 and the arm angle sensor 13 are used to calculate the position of the tip of the arm 5, and the boom 4 raising operation and the arm 5 lowering operation are individually electromagnetically proportionally reduced based on a preset “restriction range”. A controller 33 limited by the valves 30 and 31 is provided. The controller 33 is connected to a change-over switch 34 for selectively switching two types of “limitation areas” described later.

  The attachment of the boom angle sensor 12 and the arm angle sensor 13 will be described with reference to FIG. The boom angle sensor 12 is attached to the rotation center of the base of the boom 4 and detects the angle between a line connecting the base of the boom 4 and the arm rotation center at the tip and the horizontal line as the boom angle α. The arm angle sensor 13 detects an angle between a line connecting the base of the boom 4 and the arm rotation center at the tip and a line connecting the arm rotation center and the attachment rotation center at the arm tip as the arm angle β.

  The hydraulic system of the work machine 40 will be described with reference to FIG. In the boom cylinder 4a and the arm cylinder 5a, the discharge oil of the pair of hydraulic pumps 16L and 16R driven by the engine 15 is controlled by the boom flow control valves 20 and 21 and the arm flow control valves 22 and 23, respectively. The telescopic operation is performed.

  The boom flow control valves 20 and 21 and the arm flow control valves 22 and 23 are respectively a boom raising remote control valve 26, a boom lowering remote control valve 27, and an arm raising remote control valve that are operated by the pilot pressure oil from the pilot pressure source 24. 28, controlled by the arm lowering remote control valve 29, and supplied and discharged.

  The electromagnetic proportional pressure reducing valve 30 for restricting the boom raising operation is connected to the pipe connecting the boom raising remote control valve 26 and the boom flow control valves 20 and 21 with the arm lowering remote control valve 29 and the arm flow control valves 22 and 23. The electromagnetic proportional pressure reducing valve 31 for restricting the arm lowering operation is attached to the connecting pipe line.

  The “restricted area” will be described with reference to FIG. As the “restricted area”, an “arc-shaped restricted area” provided along an arcuate locus in which the cab 8 moves up and down, which can be selected by the changeover switch 34, and the lowermost position of the cab 8 and the front face of the uppermost position are connected. It is equipped with a “linear restriction area” provided along a straight line.

  The “arc-shaped restricted area” is defined by a line LMN formed by an arc LM extending from the upper side to the lower side of the radius R0 around the attachment pin C of the link 9 and a straight line MN extending horizontally inward from the lower end M. The radius R0 is obtained by adding the margin value Δr to the movable radius r of the attachment 6 from the tip of the arm shown in FIG. 3 to the radius R0 'from the front end of the cab furthest away from the pin C when the cab 8 moves up and down.

  The “linear restriction area” is a straight line QP that extends horizontally from the arc LM portion of the line LMN of the “arc restriction area” toward the cab 8 by r + Δr at the top of the cab 8 and r + Δr in front of the cab 8. It is defined by a line PQHIMN which is narrowed by a straight line HI which is separated and extends up and down.

  In order to efficiently perform the work using the attachment 6 (FIG. 3) by the work machine 40, the “arc-shaped restricted area” provided away from the cab 8 is set as “for normal use” and provided closer to the cab 8. The “linear restriction area” can be appropriately selected by the changeover switch 34 as “for emergency”.

  The controller 33 will be described with reference to FIG. The controller 33 inputs the arm angle β of the arm angle sensor 13 and outputs a boom limit angle setting unit 40 that outputs a boom limit angle in an “arc-shaped limit area”, and outputs a boom limit angle in a “linear limit area”. Boom limit angle setter 41, signal selector 42 for switching the outputs of limit angle setters 40 and 41 by changeover switch 34, the boom limit angle output from signal selector 42 and the deviation of boom angle α of boom angle sensor 12 Subtractor 43 for obtaining the pressure, boom operating pressure setting device 44 for setting a pilot pressure for performing operation restriction based on the angle deviation obtained by the subtractor 43, and the output pressure of the boom operating pressure setting device 44 for the electromagnetic proportional valve 30. A driver 45 for converting the drive signal into a drive signal is provided.

  The controller 33 also inputs the boom angle α of the boom angle sensor 12 and outputs the arm limit angle setting unit 46 that outputs the arm limit angle of the “arc-shaped limit area” and the arm limit angle of the “linear limit area”. Arm limit angle setter 47 to be operated, signal selector 48 for switching the output of limit angle setters 46 and 47 by changeover switch 34, arm limit angle output from signal selector 48 and arm angle β of arm angle sensor 13 A subtractor 49 for obtaining a deviation, an arm operating pressure setter 50 for setting a pilot pressure for performing operation restriction based on the angle deviation obtained by the subtractor 49, and an output pressure of the arm operating pressure setter 50 for an electromagnetic proportional valve A driver 51 for converting into 31 drive signals is provided.

  Next, a formula for calculating the boom limit angle and the formula for calculating the arm limit angle in the “arc-shaped limit area”, a formula for calculating the boom limit angle and the formula for calculating the arm limit angle in the “linear limit area” will be described.

(1) A formula for calculating the boom limit angle α _{LT1 in} the “arc-shaped limit area” will be described with reference to FIG.

The distance R1 from the boom mounting pin O to the arm tip pin A is given by the following equation from ΔOBA.
[Equation 1]

[数２]

Local coordinates are set with the link mounting pin C as the origin, the straight line passing through the boom mounting pin O as the x axis, and the axis perpendicular to the x axis as the y axis. Let E be the intersection of a line perpendicular to the x-axis from the intersection D of the circle of radius R0 with the link attachment pin C as the origin and the circle of radius R1 with the boom attachment pin O as the origin.

[Equation 2]

Similarly, the following equation holds from ΔODE.
[Equation 3]

By subtracting [Expression 3] from [Expression 2] and deriving an expression for obtaining _xd ,
[Equation 4]

[数５]

[Equation 5]

[数７]

The coordinates (x _d , y _d ) of the intersection point D in the local coordinates xy are converted into global coordinates XY using the following equation.
[Equation 6]

[Equation 7]

但し、Ｌ_ｏｂはブーム長、Ｌ_ａｂはアーム長、また、Ｏ点の座標を（Ｘ_ｏ,Ｙ_ｏ）とすると、
[数９]

On the other hand, if ∠AOB = α1 in FIG.
[Equation 8]

However, if L _ob is the boom length, L _ab is the arm length, and the coordinates of the O point are (X _o , Y _o ),
[Equation 9]

The boom limit angle α _LT1 is given by the following equation.
[Equation 10]

Using the above relational expression, the arm angle β is increased at a constant pitch, and the intersection of the arc of radius R0 centered on the mounting pin C of the link 9 and the arc of radius R1 connecting the boom mounting pin O and the arm tip A The coordinates (x _d , y _d ) of _D are obtained.

Next, the boom limit angle α _LT is obtained from the formulas [8], [9], and [10], and a function table of the arm angle β and the boom limit angle α _LT1 is created.

(2) A formula for calculating the arm limit angle β _LT1 of the “arc-shaped limit area” will be described with reference to FIG.

[数１２]

In FIG. 8, the coordinates (X _b , Y _b ) of the boom tip pin B are given by the following equations.
[Equation 11]

[Equation 12]

[数１３]

[Equation 13]

  As shown in FIG. 8, the local coordinates are set with the link mounting pin C as the origin, the straight line passing through the boom tip pin B as the x axis, and the axis perpendicular to the x axis as the y axis.

[数１４]

Let G be the intersection of a line perpendicular to the x-axis from the intersection F of a circle with a radius R0 with the link mounting pin C as the origin and a circle with an arm length R2 with the boom tip pin B as the origin.

[Equation 14]

Similarly, the following equation holds from ΔBFG.
[Equation 15]

From the number 14] expression minus the number 15] where the directing equation for x _f,
[Equation 16]

[数１７]

[Equation 17]

[数１９]

An expression for converting the coordinates (x _f , y _f ) of the intersection point F in the local coordinates xy into the global coordinates XY is as follows:
[Equation 18]

[Equation 19]

[数２０]

[Equation 20]

In FIG. 8, if ∠OBF = β1,
[Equation 21]

The arm limit angle β _LT is given by the following equation.
[Equation 22]

Using the above relational expression, the boom angle α is increased at a constant pitch, and the arc of the radius R0 centering on the mounting pin C of the link 9 and the arc of the radius R2 connecting the boom tip pin B and the arm tip A are intersected. The coordinates (x _f , y _f ) of _F are obtained.

Next, the arm limit angle β _LT1 is obtained from the formulas [20], [21], and [22], and a function table of the boom angle α and the arm limit angle β _LT1 is created.

(3) A formula for calculating the boom limit angle α _{LT2 in} the “linear limit range” will be described with reference to FIG. 9.

[数２３]

In FIG. 9, local coordinates xy with the boom mounting pin O as the origin are set.

[Equation 23]

The formula of radius R1 with the boom mounting pin O as the origin is
[Equation 24]

From [Expression 23] and [Expression 24]
[Equation 25]

[数２５]式は、次式で与えられる。
[数２６]

Replace the coefficients with the following equations:

The formula [25] is given by the following formula.
[Equation 26]

[数２８]

When B ₁ ² -4A ₁ C ₁ > 0, the coordinate x _j of the intersection point is obtained by the following equation.
[Equation 27]

[Equation 28]

[数３０]

An expression for converting the coordinates (x _j , y _j ) of the intersection point J in the local coordinates xy into the global coordinates XY is
[Equation 29]

[Equation 30]

[数３２]

On the other hand, if ∠AOB = α1 in FIG.
[Equation 31]

[Equation 32]

The boom limit angle α _LT2 is given by the following equation.
[Equation 33]

を求める。 Using the above relation, increasing the arm angle β at a constant pitch,

Ask for.

Next, the boom limit angle α _LT2 is obtained from the formulas [31], [32], and [33], and a function table of the arm angle β and the boom limit angle α _LT2 is created.

(4) A formula for calculating the arm limit angle β _LT2 of the “linear limit region” will be described with reference to FIG.

[数３４]

In FIG. 10, local coordinates xy with the boom mounting pin O as the origin are set.

[Equation 34]

[数３６]

In FIG. 10, the coordinates (x _b , x _b ) of the boom tip pin B are given by the following equations.
[Equation 35]

[Equation 36]

The formula of radius R2 with the boom tip pin B as the origin is
[Equation 37]

係数を以下の式に置き換える。

[数３８]式は、次式で与えられる。
[数３９]

From [Expression 34] and [Expression 37]
[Equation 38]

Replace the coefficients with the following equations:

The equation [Equation 38] is given by the following equation.
[Equation 39]

[数４１]

When B ₂ ² -4A ₂ C ₂ > 0, the coordinate x _k of the intersection is obtained by the following equation.
[Equation 40]

[Equation 41]

[数４２]

[Equation 42]

アーム制限角β_ＬＴ２は、次式で与えられる。
[数４４]

In FIG. 10, if ∠OBK = β2,
[Equation 43]

The arm limit angle β _LT2 is given by the following equation.
[Equation 44]

を求める。 Using the above relational expression, increasing the boom angle α at a constant pitch,

Ask for.

Next, the arm limit angle β _LT2 is obtained from the equations [Expression 42], [Expression 43], and [Expression 44], and a function table of the boom angle α and the arm limit angle β _LT2 is created.

  Next, interference prevention control in the interference prevention apparatus 50 will be described with reference to FIG.

Restriction of boom raising operation:
The arm angle 13 is input to a boom limit angle setting device 40 that outputs a boom limit angle in an “arc-shaped limit range” and a boom limit angle setter 41 that outputs a boom limit angle in a “linear limit range”. The boom limit angle is output from the boom limit angle setting devices 40 and 41.

  The boom limit angle setting unit 40 is a function table created by calculating the boom limit angle with respect to the arm angle β in the limit region LMN using the above-described formula for calculating the boom limit angle. The boom limit angle setting unit 41 is a function table created by calculating the boom limit angle with respect to the arm angle β in the limit area PQHIMN using the above-described formula for calculating the boom limit angle.

  The two boom limit angle setting devices 40 and 41 are switched by the signal selector 42 by the changeover switch 34, and the boom limit angle is output. A subtractor 43 obtains a deviation between the boom limit angle output from the signal selector 42 and the boom angle 12. The angle deviation obtained by the subtractor 43 is input to the boom operation pressure setting unit 44, a pilot pressure for limiting the boom raising operation is set, converted into a drive signal for the electromagnetic proportional valve 30 by the driver 45, and the boom raising is performed. Limit operations.

Restriction of arm lowering operation:
The boom angle 12 is input to an arm limit angle setter 46 that outputs an arm limit angle in an arc-shaped limit area and an arm limit angle setter 47 that outputs an arm limit angle in a linear limit area. Arm limit angles are output from the units 46 and 47.

  The arm limit angle setting unit 46 is a function table created by calculating the arm limit angle with respect to the boom angle α in the limit region LMN using the above-described formula for calculating the arm control angle. The arm limit angle setting unit 47 is a function table created by calculating the arm limit angle with respect to the boom angle α in the limit area PQHIMN using the above-described formula for calculating the arm control angle.

  The switch selector 34 switches the two arm limit angle setting units 46 and 47 by the signal selector 48 to output the arm limit angle. The subtractor 49 obtains the deviation between the arm limit angle output from the signal selector 48 and the arm angle 13. The angle deviation obtained by the subtractor 49 is input to the arm operation pressure setting device 50, a pilot pressure for limiting the arm lowering operation is set, converted into a drive signal of the electromagnetic proportional valve 31 by the driver 51, and the arm lowering Limit operations.

  The effect of the working machine interference prevention apparatus as described above will be described.

  The working machine interference prevention device 50 configured in accordance with the present invention restricts the movement of the work arm 3 based on a preset limit range based on the lowest position and the highest position of the cab 8.

  Accordingly, since the movement of the work arm 3 is limited based on the preset limit area without detecting the position of the elevating cab 8 and correcting the limit area, the control calculation of the interference prevention device 50 is simplified. be able to.

  As the restriction area, an arc-shaped restriction area provided along an arc-shaped locus in which the cab 8 moves up and down is provided. Alternatively, as another example of the restriction area, a linear restriction area provided along a straight line connecting the lowest position of the cab 8 and the front face of the highest position is provided.

  Therefore, an “arc-shaped restricted area” provided away from the cab 8 or a “linear restricted area” provided closer to the cab 8 may be set in advance according to the work of the work implement 40.

  In addition, an arc-shaped restriction area provided along an arc-shaped locus in which the cab 8 moves up and down as a restriction area and a linear restriction area provided along a straight line connecting the lowermost position of the cab 8 and the front face of the uppermost position are selected. A change-over switch 34 is provided for switching freely.

  Therefore, the “arc-shaped restricted area” provided away from the cab 8 is set as “for normal use”, and the “linear restricted area” provided closer to the cab 8 is set as “for emergency use” as appropriate by the changeover switch 34. By doing so, the work can be efficiently performed according to the work form of the work machine 40, the type of attachment, and the like.

  The controller 33 of the interference prevention device 50 calculates the position of the tip of the arm 5 based on the outputs of the boom angle sensor 12 and the arm angle sensor 13, and performs the raising operation of the boom 4 and the lowering operation of the arm 5 based on the restricted area. Limit individually.

  Therefore, since the operation of raising the boom 4 and the operation of lowering the arm 5 of the work arm 3 are individually restricted, it is possible to improve workability deterioration due to simultaneous restriction of the operations of the boom 4 and the arm 5.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various changes or modifications can be made within the scope of the present invention, for example, as described below. Is.

  In the embodiment of the present invention, the two limit areas, the arc-shaped limit area, and the linear limit area are selectively switched by the changeover switch 34, but only one of them is selected depending on the work mode of the work implement. You may make it provide.

2: Upper turning body (airframe)
3: Work arm 4: Boom 5: Arm 12: Boom angle sensor 13: Arm angle sensor 33: Controller 34: Changeover switch 40: Work machine 50: Interference prevention device

Claims (5)

A device for preventing interference between a cab of a working machine and a work arm tip located in front of the cab, which includes a cab that can be freely moved up and down and an articulated work arm that can be freely swung up and down. There,
Limit the movement of the work arm based on the preset limit range by the cab bottom position and top position,
An interference prevention device for a working machine. As the limit area,
It has an arc-shaped restricted area provided along an arc-shaped trajectory in which the cab moves up and down,
The work machine interference preventing apparatus according to claim 1. As the limit area,
It has a linear restriction area provided along a straight line connecting the lowest position of the cab and the front face of the highest position.
The work machine interference preventing apparatus according to claim 1. As the limit area,
An arc-shaped restriction area provided along an arc-shaped trajectory where the cab moves up and down, and a linear restriction area provided along a straight line connecting the lowermost position of the cab and the front face of the uppermost position, which can be selected by a changeover switch. Have
The work machine interference preventing apparatus according to claim 1. The work arm includes a boom that is freely swingable in the vertical direction on the machine body, and an arm that is freely swingable in the vertical direction at the tip of the boom.
Interference prevention device
A boom angle sensor for detecting the swing angle of the boom relative to the airframe;
An arm angle sensor for detecting the swing angle of the arm with respect to the boom; and
A controller that calculates the position of the tip of the arm based on the outputs of the boom angle sensor and the arm angle sensor, and individually restricts the boom raising operation and the arm lowering operation based on the restricted area.
5. The working machine interference prevention apparatus according to claim 1, wherein

Images