JP2546592Y2 - Boom height limiting device for working machine with boom - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom height limiting device for a working machine having a boom.

[0002]

2. Description of the Related Art Conventionally, there is a mobile crane A as a working machine having such a boom. Hereinafter, the boom height limiting device of the mobile crane A will be described. As shown in FIG. 4, this type of mobile crane A is provided with a swivel base 2 which can be swiveled on a vehicle 1, and has a telescoping boom 3 which can be raised and lowered on the swivel base 2. The hydraulic cylinder 4 for raising and lowering is arranged between them. The telescopic boom 3 has a base boom 5 and an intermediate boom 6 and a leading boom 7 that are sequentially fitted therein so as to be extendable and contractable, and is provided with telescopic driving means such as a hydraulic cylinder between the respective booms.

[0003] The mobile crane A constructed as described above raises and lowers the telescopic boom 3 and drives the telescopic boom 3 so that the tip of the telescopic boom 3 is located at a high place. As shown in FIG. When an obstacle B such as a building is positioned, the tip of the telescopic boom 3 comes into contact with the obstacle B and the mobile crane A or an obstacle B such as an electric wire or a building.
Could be damaged. In order to prevent this, a movable crane A
Was prepared for.

As shown in FIG. 5, the boom height limiting device C includes an up-and-down angle detector 8 for detecting an up-and-down angle θ of the telescopic boom 3 and a boom length detector for detecting a boom length 1 of the telescopic boom 3. 9, an operation unit 10 for obtaining an actual value L which is the actual height of the end of the telescopic boom 3 based on the detection values from these detectors, and a setting unit 11 for setting a height limit value L 'of the end of the telescopic boom 3 A comparing unit 12 for comparing whether the actual value L has reached the limit value L 'and outputting a signal based on the result, and raising and extending the telescopic boom 3 based on the signal from the comparing unit 12; A regulating means 13 for regulating is provided.

The boom height limiting device C constructed as described above operates as follows. When an obstacle B such as an electric wire or a building is positioned above the mobile crane A when working with the mobile crane A as shown in FIG. 4, the operator firstly operates the height limit value L ′ slightly lower than the height of the obstacle B. Is set in the setting device 11 in advance. Then, the undulation angle detector 8 detects the undulation angle θ of the telescopic boom 3 and the length detector 9 detects the boom length l. Then, the actual value L which is the height of the tip of the telescopic boom 3 is calculated from the undulation angle θ and the boom length 1 by the arithmetic unit 10
(= 1SINθ) is calculated.

The comparing unit 12 compares whether the actual value L calculated by the arithmetic unit 10 has reached the limit value L 'set by the setting unit 11, and the actual value L reaches the limit value L'. Signal is output to the regulating means 13. Regulatory measures 1
At 3, the raising and extending movement of the telescopic boom 3 is regulated based on the signal from the comparison unit 12. Therefore, in the mobile crane provided with the boom height limiting device C, the raising and extending movement of the telescopic boom 3 is restricted before the tip of the telescopic boom 3 contacts the obstacle B, and the mobile crane is controlled. A or obstacle B can be prevented from being damaged.

[0007]

However, a working machine having a boom provided with such a boom height limiting device C has the following problems. That is, when the telescopic boom 3 is extended, the vertical movement amount at the tip of the telescopic boom 3 due to the unit extension movement of the telescopic boom 3 does not change with the length of the telescopic boom 3. However, when raising the telescopic boom 3, the amount of vertical movement at the tip of the telescopic boom 3 greatly changes depending on the amount of extension of the telescopic boom 3, so that the telescopic boom 3 is set even if the limit value L ′ is set. In some cases, the limit value L 'may be overrun depending on the extension amount of the telescopic boom, and in the worst case, the tip of the telescopic boom 3 may contact the obstacle B.

That is, even when the telescopic boom 3 is raised by the same angle, the telescopic boom 3 has a relatively short length and a long telescopic boom 3. The amount of movement is different. That is, in the boom height limiting device C, when the telescopic boom 3 is relatively short in length, even if the telescopic boom 3 is raised, the telescopic boom 3 can be raised before coming into contact with the obstacle B. Can be stopped, but if the length of the telescopic boom 3 is relatively long, the raising and lowering of the telescopic boom 3 cannot be stopped before the telescopic boom 3 comes into contact with the obstacle B.

Therefore, the operator has taken measures such as appropriately changing the limit value L 'according to the boom length 1 by the setting device 11. However, the length of the telescopic boom 3 is changed as appropriate during the work, and it is practically impossible to change the limit value L 'by the setting device 11 each time, since the operator is burdened with an excessive burden. An object of the present invention is to provide a boom height limiting device for a working machine having a new boom that has solved the above-mentioned problems.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, a boom height limiting device for a working machine having a boom according to the present invention is provided with a telescopic boom which can be raised and lowered on a vehicle, and the undulation angle of the telescopic boom can be reduced. An elevation angle detector to detect, a length detector to detect the boom length of the telescopic boom, a calculation unit to calculate the actual value which is the actual height of the telescopic boom tip based on the detection values from these detectors, telescopic A setting unit that sets the height limit value of the boom tip, a comparison unit that compares whether the actual value has reached the limit value and outputs a signal based on the result, and an extension boom based on the signal from the comparison unit. boom height limit device for a working machine having a boom with a restricting means for restricting the Osshado met
Te, based on the detection value from the correction unit and the respective detectors, to correct the limiting value as occupying become small the limiting value with increasing detected values based on the boom lengths from the length detector The present invention is characterized in that a correction means is provided for obtaining a boom working radius and correcting the limit value so as to reduce the limit value as the working radius increases.

[0011]

The boom height limiting device for a working machine having a boom according to the present invention, constructed as described above, corrects the limit value by means of the correction means so as to reduce the limit value as the boom length or the boom working radius increases. Therefore, when the telescopic boom is extended, the raising and lowering of the telescopic boom is regulated by a limit value smaller than the limit value set by the setting device as compared with the case where the telescopic boom is contracted. The extension boom can be stopped with enough time,
The overrun can prevent the tip of the telescopic boom from contacting the obstacle. Further, once the limit value is set by the setting device, the operator does not have to perform a troublesome operation of appropriately changing the limit value depending on the boom length each time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 when it is applied to a mobile crane A described in the background art. Reference numerals 1 to 13, reference numerals A and B, which are shown and described in FIGS. 4 and 5 in the related art, are the same and will be used below to omit the description. In FIG. 1, reference numeral D denotes a boom height limiting device of the present invention, which is different from the boom height limiting device C described in the related art in that correction device described below is provided. The parts are the same as those provided in the boom height limiting device C, and therefore the description is omitted.

Reference numeral 14 denotes a correction means, which comprises a correction value storage unit 15 and a limit value subtraction unit 16. The correction value storage unit 15 stores a correction value L ″ that reduces the limit value L ′ as the length of the telescopic boom 3 increases based on the detection value from the length detector 9 (that is, the correction value L ″). Correction value L "
Are stored in such a relationship that the value increases as the length of the telescopic boom 3 increases. ) Limit value subtraction unit 1
Numeral 6 is for calculating a corrected limit value by subtracting the correction value L ″ output from the correction value storage unit 15 from the limit value L ′ output from the setting unit 11.

The boom height limiting device D provided in the mobile crane A according to the present invention thus constructed operates as follows. That is, the correction value L ″ is output from the correction value storage unit 15 based on the boom length 1 detected by the length detector 9, and the limit value L ′ set by the setting unit 11 by the limit value subtraction unit 16 is changed to L′−. L ”. Therefore, the comparison unit 12 compares the actual value L calculated by the calculation unit 10 with the limit value L'-L ".

Therefore, as the boom length becomes longer, the correction value L ″ output from the correction value storage unit 15 becomes a larger value, and the limit value L ′ is made smaller, so that the actual value L becomes smaller than the limit value L ′. −L ”is reached earlier than the conventional boom height limiting device C. Therefore, the comparison unit 12
Thus, the signal is output earlier, and the raising and lowering movement of the telescopic boom 3 can be restricted via the restricting means 13, so that the tip of the telescopic boom 3 can be prevented from contacting the obstacle B by that much. . The extension movement of the telescopic boom 3 may be restricted similarly to the restricting means 13 described in the related art.

As described above, the limit value L 'is corrected according to the length of the telescopic boom 3.
When the vertical movement amount at the tip of the telescopic boom 3 changes according to the extension amount of the telescopic boom 3, overrun occurs depending on the extension amount of the telescopic boom 3, and in the worst case, the tip of the telescopic boom 3 is moved to the obstacle B. Can be prevented from coming into contact with the object.

Although the correction means 14 in the above embodiment corrects the limit value L 'by subtraction, the limit value L' is corrected.
May be multiplied or divided by a correction coefficient. In this case, when the limit value L 'is multiplied by the correction coefficient, the correction coefficient is set so that the result of the multiplication becomes smaller as the boom length becomes longer. When the correction coefficient is divided by the limit value L', the boom length is used. The correction coefficient may be reduced so that the result of the division becomes smaller as the length of the correction becomes longer.

Next, in the above-described embodiment, the case where the correction means 14 for correcting the limit value L 'according to the boom length is described, but the limit value L' may be corrected according to the working radius of the boom. . An embodiment of the boom height limiting device E in this case is shown in FIG. 2 and will be described below. Since the boom height limiting device E differs from the boom height limiting device D only in the correction means, only this portion will be described below.

In FIG. 2, reference numeral 17 denotes a correction means, which comprises a work radius calculation section 18, a correction value storage section 19, and a limit value subtraction section 20. The work radius calculation unit 18
The working radius R (= lCOSθ) is calculated based on the detected values of the undulation angle detector 8 and the length detector 9. Correction value storage unit 19
Stores a correction value L ″ that reduces the limit value L ′ as the work radius R increases based on the work radius R calculated by the work radius calculation unit 18 (that is, the correction value L ″ is The value is stored in such a manner that the value increases as the working radius R increases.)
Calculates the corrected limit value by subtracting the correction value L ″ output from the correction value storage unit 19 from the limit value L ′ output from the setting unit 11.

Therefore, as the work radius R becomes longer, the correction value L ″ output from the correction value storage unit 19 becomes larger and the limit value L ′ is made smaller, so that the actual value L becomes smaller than the limit value L ′. −L ”is reached earlier than the conventional boom height limiting device C. Therefore, the comparison unit 12
Thus, the signal is output earlier and the raising and lowering movement of the telescopic boom 3 can be restricted via the restricting means 13, so that the tip of the telescopic boom 3 can be prevented from contacting the obstacle B by that much. In this case, the restricting means 13 also controls the extension boom 3
May also be restricted. Further, the correction means 17 in the above embodiment corrects the limit value L 'by subtraction, but similarly multiplies or divides the limit value L' by a correction coefficient as described for the boom height limiting device D. Needless to say, it may be done.

It should be noted that the case where the limit value L 'is corrected with the working radius R and the case where the limit value L' is corrected with the boom length 1 both achieve the object of the present invention. Although they can be done, there are the following differences. That is, without changing the boom length (the telescopic boom 3
Let's consider a case in which only the raising operation of the telescopic boom 3 is performed (without performing the telescopic operation of). In this case, since the boom length does not change, when the limit value L 'is corrected by the boom length l, when the limit value L' set by the setting unit 11 is small and large (in other words, For example, when the boom height limit is low and high), the correction value L ″ output from the correction value storage unit 15 of the correction unit 14 is the same value.

However, when the limit value L 'is corrected by the work radius R, the limit value L' set by the setting unit 11 is small and large (in other words, when the boom height limit is low). The value of the correction value L "output from the correction value storage unit 19 of the correction means 17 is different. That is, even when the boom length is the same, the case where the telescopic boom 3 is lying down is raised. The reason for this is that the working radius R is different, that is, when the boom height limit is low, the limit value L ′ set by the setting device 11 is corrected to be small, and the elevating movement of the telescopic boom 3 is increased. It can be regulated from an early stage. When the boom height limit is high, the setting device 11
The limit value L 'is corrected so as not to reduce the limit value L' set in the above step, so that the raising and lowering movement of the telescopic boom 3 is not restricted from an early stage.

This means that, even when the telescopic boom 3 is lying down, the vertical movement displacement at the tip of the telescopic boom 3 is large when the telescopic boom 3 is lying down, even if the telescopic boom 3 has the same boom length. Conversely, when raising the telescopic boom 3 with the same boom length, the vertical movement displacement at the tip of the telescopic boom 3 is small if the raising speed of the telescopic boom is constant. Limit value L 'by R
Can be said to be more effective.

Next, a development example of the above embodiment will be described with reference to FIG. In FIG. 3, F denotes a boom height limiting device, which is different from the boom height limiting device E in that a raising operation detector 21 and a switching means 22 are arranged. The raising operation detector 21 is a detector that detects that the telescopic boom 3 has been raised. Switching means 22
Receives the signal from the raising operation detector 21, sends the limit value L'-L "from the correcting means 17 to the comparing section 12 when the raising operation is performed, and sets the limit value when the raising operation is not performed. The limit value L ′ from the detector 11 is sent directly to the comparison unit 12.

The boom height limiting device F thus configured
Indicates that the extension speed of the telescopic boom 3 is relatively slow.
The vertical displacement at the tip of the telescopic boom 3 caused by the extension of the telescopic boom 3 is small. That is, when the telescopic boom 3 is being raised, the limit value is corrected by the correcting unit 17, and when the telescopic boom 3 is expanded or contracted, the limit value set by the setting unit 11 is not corrected by the correcting unit 17 and is unchanged. To use.

Although the above-described boom height limiting device has been described as applied to a mobile crane A, it is needless to say that the device can be applied to a work vehicle having a boom such as an aerial work vehicle, a digging pole and the like. It is.

[0027]

The boom height limiting device of the working machine having the boom according to the present invention configured and operated as described above raises the telescopic boom when the telescopic boom is extended as compared with when the telescopic boom is contracted. Movement is regulated by a limit value smaller than the limit value set by the setting device, and as soon as the actual boom height reaches the limit value and the boom raising motion is regulated, it does not overrun. The elevating movement of the telescopic boom can be stopped with a margin, and it is possible to prevent the tip of the telescopic boom from coming into contact with an obstacle. Further, once the limit value is set by the setting device, the operator does not have to perform a troublesome operation of appropriately changing the limit value depending on the boom length each time.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating a boom height limiting device of a working machine having a boom according to the present invention.

FIG. 2 is an explanatory view illustrating a boom height limiting device of a working machine having a boom according to the present invention, and is an explanatory view of another embodiment.

FIG. 3 is an explanatory view illustrating a boom height limiting device of a working machine having a boom according to the present invention, and is an explanatory view illustrating an advanced example.

FIG. 4 is an explanatory diagram illustrating a mobile crane.

FIG. 5 is an explanatory view illustrating a conventional boom height limiting device for a working machine having a boom.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vehicle 3 telescopic boom 8 undulation angle detector 9 length detector 10 calculation unit 11 setting unit 12 comparison unit 13 regulating means 14 correction means 17 correction means D boom height limiter E boom height limiter F boom height limit apparatus

Claims (1)

(57) [Scope of request for utility model registration] An undulating telescopic boom is provided on a vehicle,
An elevation angle detector that detects the elevation angle of the telescopic boom, a length detector that detects the boom length of the telescopic boom, and an actual value that is the actual height of the telescopic boom tip based on the detection values from these detectors The calculation unit that determines the height limit value of the telescopic boom tip, the setting unit that compares whether the actual value has reached the limit value, the comparison unit that outputs a signal based on the result, and the signal from the comparison unit Boom height limiting device for a working machine having a boom provided with a restricting means for restricting the elevating movement of the telescopic boom
A is, correction means for correcting the limit value as occupying become small the limiting value with increasing boom lengths based on detection values from the length detector, or the detection value from each detector A boom height limiting device for a working machine having a boom, comprising: a correcting means for determining a boom working radius based on the calculated working radius and reducing the limiting value as the working radius increases.