JP2546593Y2 - 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. 5, this type of mobile crane A is provided with a swivel base 2 which can be swiveled on a vehicle 1, and has a telescopic boom 3 which can be raised and lowered. 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.

The mobile crane A constructed as described above moves the telescopic boom 3 up and down and moves the telescopic boom 3 so that the tip of the telescopic boom 3 is located at a high position. 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. 6, the boom height limiting device C includes an up / down angle detector 8 for detecting an up / 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 working with the mobile crane A, if an obstacle B such as an electric wire or a building is located above as shown in FIG. 5, 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, in a working machine having a boom provided with such a boom height limiting device C, recently, the telescopic boom 3 has a simultaneous telescopic system (one telescopic hydraulic system). A telescopic drive transmission means such as a cylinder and a wire rope is arranged, and a single telescopic hydraulic cylinder is used to simultaneously extend and retract a multi-stage boom, or a number of telescopic hydraulic cylinders are arranged between each boom, and these telescopic hydraulic cylinders are used. The telescopic boom 3 has the following problem because the telescopic boom 3 has a higher telescopic speed.

That is, when the telescopic boom 3 is extended, the amount of vertical movement at the tip of the telescopic boom 3 due to the extension movement of the telescopic boom 3 changes depending on the undulation angle of the telescopic boom 3. Is smaller than the extension amount of the telescopic boom 3 in the vertical direction, and the telescopic boom 3 is larger if the undulation angle of the telescopic boom 3 is large.
The amount of movement in the vertical direction also increases in proportion to the amount of extension of. Therefore, even if the limit value L 'is set, the limit value L' may be overrun depending on the undulation angle of the telescopic boom 3, and in the worst case, the tip of the telescopic boom 3 may come into contact with the obstacle B. Was.

In other words, when the same boom height restriction is performed, there are cases where the stop of the boom at the end of the boom to be restricted is high and that at the time of the low end of the boom are stopped or not in time. That is, when the tip height of the boom to be restricted is high, the telescopic boom 3 is raised, and when the tip height of the boom to be restricted is low, the telescopic boom 3 is mostly laid down. Therefore, even if the telescopic boom 3 is extended at the same speed according to the undulation angle of the telescopic boom 3, the vertical movement amount of the tip of the telescopic boom 3 is larger when the telescopic boom 3 has a larger undulation angle. Is large as compared with the case where is small. Accordingly, when the telescopic boom 3 is extended by raising the telescopic boom 3, the extension movement of the telescopic boom 3 may not be able to be stopped before coming into contact with the obstacle B.

Therefore, the operator has taken measures such as appropriately changing the limit value L 'according to the boom angle θ by the setting device 11. However, the undulation angle of the telescopic boom 3 changes as needed during the operation, and changing the limit value L ′ by the setting device 11 each time is not practical because it imposes an excessive burden on the operator. 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.

[0011]

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 of the telescopic boom based on the signal from the comparison unit met boom height limit device for a working machine having a boom with a restricting means for restricting the movement
Te, corrects the limit value as occupying become small the limiting value with increasing hoisting angle function of the telescopic boom seeking hoisting angle function of the telescopic boom obtained based on the detected value from the hoisting angle detector correction means It is characterized by having.

[0012]

According to the boom height limiting device of the working machine having the boom of the present invention constructed as described above, the limiting value is corrected by the correcting means so as to reduce the limiting value as the undulation function of the telescopic boom increases. Therefore, when the telescopic boom is raised, the extension movement of the telescopic boom is regulated by a limit value smaller than the limit value set by the setting device, compared to when the telescopic boom is lying down. Therefore, the extension movement of the telescopic boom can be stopped with a sufficient margin, and the tip of the telescopic boom can be prevented from contacting an obstacle due to overrun. 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 angle every time.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case in which an embodiment of the present invention is applied to a mobile crane A described in the prior art will be described below with reference to FIGS. Reference numerals 1 to 13, reference numerals A and B, which are shown and described with reference to FIGS. 5 and 6 in the related art, are the same, and are also 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.

In FIG. 1, reference numeral 14 denotes a correction means, which comprises a correction value storage section 15 and a limit value subtraction section 16. The correction value storage unit 15 stores a correction value L ″ that reduces the limit value L ′ as the undulation angle of the telescopic boom 3 increases based on the detection value from the undulation angle detector 8.
(That is, the correction value L ″ is stored in such a manner that the value increases as the undulation angle of the telescopic boom 3 increases.) The limit value subtraction unit 16 outputs the limit value output from the setting unit 11. The corrected limit value L'-L "is calculated by subtracting the correction value L" output from the correction value storage unit 15 from L '. The restriction 13' restricts the extension movement of the telescopic boom 3. Means.

The boom height limiting device D provided to the mobile crane A according to the present invention thus constructed operates as follows. That is, the correction value L ″ is stored in the correction value storage unit 15 according to the undulation angle θ detected by the undulation angle detector 8.
And the limit value subtraction unit 16 corrects the limit value L ′ set by the setting unit 11 to L′−L ″. Therefore, the comparison unit 12 calculates the actual value L calculated by the calculation unit 10 and the limit value L. '
−L ″.

Accordingly, the correction value L ″ output from the correction value storage unit 15 increases as the undulation angle θ of the telescopic boom 3 increases, and the limit value L ′ is reduced. The actual value L reaches the limit value L'-L "earlier than the limit device C. Therefore, the signal is output from the comparing section 12 earlier, and the extension movement of the telescopic boom 3 can be restricted via the restricting means 13 ′, so that the tip of the telescopic boom 3 contacts the obstacle B by that much. Can be blocked. In addition, regulation means 1
The raising and lowering movement of the telescopic boom 3 may be restricted to 3 'by using the restricting means 13 described in the related art, similarly to the related art.

As described above, the limit value L 'is corrected by the undulation angle of the telescopic boom 3, so that the vertical movement amount at the tip of the telescopic boom 3 changes according to the undulation angle of the telescopic boom 3. By doing so, it is possible to prevent an overrun depending on the undulation angle of the telescopic boom 3 and, in the worst case, to contact the tip of the telescopic boom 3 with the obstacle B.

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 undulation angle of the telescopic boom 3 increases, and when the correction coefficient is divided by the limit value L', This correction coefficient may be set so that the result of the division becomes smaller as the undulation angle of the telescopic boom 3 becomes larger.

Next, in the above-described embodiment, the case where the correcting means 14 for correcting the limit value L 'according to the undulation angle of the telescopic boom 3 has been described, but the limit value L' is corrected based on the height of the end of the boom. It may be. 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 unit, which comprises a correction value storage unit 18 and a limit value subtraction unit 19. The correction value storage unit 18 stores a correction value L1 " that decreases the limit value L 'as the actual value L increases based on the actual value L which is the actual tip height of the telescopic boom 3 obtained by the arithmetic unit 10. (That is, the correction value L
1 " is stored in such a relationship that the actual value L increases as the actual value L increases.)
The corrected limit value L'-L1 "is calculated by subtracting the correction value L1" output from the correction value storage unit 18 from the limit value L 'output from the setting unit 11.

Therefore, as the actual value L increases, the correction value L 1 ″ output from the correction value storage unit 18 increases, and the limit value L ′ decreases.
The actual value L reaches the limit value L'-L1 "earlier than the conventional boom height limiter C. Therefore, the signal is also output from the comparison unit 12 earlier and the restricting means 13 '.
, The extension movement of the telescopic boom 3 can be regulated,
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 'may be the restricting means 13 used in the prior art, and may also restrict the raising and lowering movement of the telescopic boom 3. 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.

Next, in the above embodiment, the correction means 14 and 17
Is set to correct the set value L ′ to restrict the extension movement of the telescopic boom 3. Similarly, when restricting the elevating movement of the telescopic boom 3, the set value L ′ may be corrected as follows. . That is, even when the telescopic boom is raised, the vertical movement amount at the tip of the telescopic boom 3 is relatively different between the case where the length of the telescopic boom 3 is relatively short and the case where it is long. different. That is, when the length of the telescopic boom 3 is relatively short, the raising and lowering of the telescopic boom 3 can be stopped before the telescopic boom 3 comes into contact with the obstacle B even if the telescopic boom 3 is raised. When the length of the boom 3 is relatively long, the raising and lowering movement of the telescopic boom 3 cannot be stopped before the boom 3 comes into contact with the obstacle B.

Therefore, when restricting the raising and lowering movement of the telescopic boom 3, the telescopic boom length function obtained based on the detection value from the length detector 9 is obtained, and the above-mentioned telescopic boom length function is increased. The limit value may be corrected so as to reduce the limit value L '. For example, it may be configured as a boom height limiting device F as shown in FIG. The boom height limiting device F differs from the boom height limiting devices D and E only in the correction means and the regulating means, and only the differences will be described below.

In FIG. 3, reference numeral 20 denotes a correction means, which comprises a work radius calculation unit 21, a correction value storage unit 22, and a limit value subtraction unit 23. Work radius calculator 21
Calculates the boom working radius R (= lCOSθ) based on the detected values of the undulation angle detector 8 and the length detector 9. The correction value storage unit 22 stores a correction value L2 "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 21 (ie, correction). The value L2 "is stored in such a manner that the value increases as the working radius R increases.) The limit value subtraction unit 23 calculates the correction value storage unit from the limit value L 'output from the setting unit 11. The corrected limit value L'-L2 "is calculated by subtracting the correction value L2" output from the counter 22. 1
Reference numeral 3 "denotes a restricting means for restricting the elevating movement of the telescopic boom 3.

Therefore, as the working radius R becomes longer, the correction value L2 "output from the correction value storage unit 22 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'. -L2 "is reached quickly.
Therefore, the signal is output from the comparing section 12 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 contacts the obstacle B by that much. In this case as well, the restricting means 13 "may be used as the restricting means 13 to restrict the extension movement of the telescopic boom 3. Further, the correction means 22 in the above-described 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 limiter D. Needless to say, it may be done.

In the embodiment of the boom height limiting device F,
Although the working radius R is used as the telescopic boom length function, the boom length of the telescopic boom 3 detected by the telescopic boom 3 length detector 9 may be directly used. Alternatively, the boom height (L = lSINθ) may be used as the telescopic boom length function.

As described above, the boom height limiting device controls the extension movement when the extension boom 3 is extended and the extension movement restriction when the extension boom 3 is raised. Since the correction means for correcting the limit value L 'set by the setting device is different between and, the correction of the limit value L' needs to be distinguished between when the telescopic boom 3 is extended and when it is raised. There is. Accordingly, the two boom height limiting devices of the boom height limiting device D or the boom height limiting device E shown in FIG. 1 or FIG. 2 and the boom height limiting device F shown in FIG. It is necessary to arrange it on the working machine that has it. Alternatively, it may be implemented as a boom height limiting device shown in FIG. 4 and described below. Hereinafter, an example of development of the present invention will be described with reference to FIG.

In FIG. 4, reference numeral G denotes a boom height limiting device, which is provided with two correction means , a correction means 17 and a correction means 20 . Since these correction means 17 and 20 have already been described in the description of the above embodiment, detailed description thereof will be omitted here. An extension operation detector 24 detects an extension operation of the telescopic boom 3. 25 is the telescopic boom 3
Is a raising operation detector for detecting the raising operation of the user. 26 is
This is a two-operation discriminator that determines from the detectors of the extension operation detector 24 and the raising operation detector 25 that the extension operation and the raising operation of the telescopic boom 3 have been performed. 27 is a limit value subtraction unit 1
9 and the limit value subtraction unit 22
Is a limit value comparison unit that compares the corrected limit value L'-L2 "from the output value and outputs the smaller limit value.

R1 is a relay that is activated when the extension operation detector 24 detects extension operation of the telescopic boom 3, and closes the contact R1a. However, only when a relay contact R3b1 described later is closed. R2 is a relay that is activated when the raising operation detector 25 detects the raising operation of the telescopic boom 3, and closes the contact R2a. However, only when a relay contact R3b2 described later is closed. R3 is a two-operation classifier 2
6 is a relay that operates in response to a signal from the relay 6 and closes the contact R3a and opens the contacts R3b1 and R3b2.

R1a is a relay contact operated by the relay R1, and is interposed between the limit value subtracting section 19 and the comparing section 12. R2a is a relay contact operated by the relay R2, and is interposed between the limit value subtracting unit 23 and the comparing unit 12. R3a is a relay contact operated by the relay R3, and is interposed between the limit value comparison unit 27 and the comparison unit 12. R3b1 is a relay contact opened by the operation of the relay R3, and is interposed in series with the relay R1. R3b2
Are relay contacts that are opened by the operation of the relay R3, and are interposed in series with the relay R2.

The boom height limiting device G configured as described above
Works as follows. First, telescopic boom 3
When extending the extension boom 3
, The relay R1 is actuated. Then, the relay contact R1a is closed, and the comparison unit 12 compares the actual value L from the calculation unit 10 with the limit value L'-L1 "from the limit value subtraction unit 19.
When the telescopic boom 3 is extended, the extension movement of the telescopic boom 3 is regulated by the limit value L'-L1 "obtained by correcting the set value L 'from the setting device 11 by the correcting means 17.

Next, when raising the telescopic boom 3, the raising operation detector 25 detects that the telescopic boom 3 is being raised, and activates the relay R2. Then, the relay contact R2a is closed, and the comparison unit 12 compares the actual value L from the arithmetic unit 10 with the limit value L'-L2 "from the limit value subtraction unit 23. That is, the telescopic boom 3 is raised. In this case, the raising and lowering movement of the telescopic boom 3 is restricted by the limit value L'-L2 "obtained by correcting the set value L 'from the setter 11 by the correcting means 20.

When the telescopic boom 3 is extended and raised, the two-operation discriminator 26 determines from the signals from the extension operation detector 24 and the raised operation detector 25 that both operations have been performed, and relays them. Activate R3. Then the relay contact R
3b1 and R3b2 open their contacts, relay R1 and relay R
2 does not work. Relay contact R is activated by the operation of relay R3.
3a is closed, and the comparison unit 12 outputs the actual value L from the calculation unit 10.
And the signal from the limit value comparing unit 27 (the corrected limit value L'-L1 "from the limit value subtracting unit 19 and the corrected limit value L'-L2" from the limit value subtracting unit 23, and the smaller limit is compared. value)
Will be compared. In other words, when the telescopic boom 3 is extended and raised, the limit value L ′ from the setting device 11 is corrected by the correction means 17 or the limit value corrected by the correction means 20, whichever is smaller. The extension movement and the raising movement of the telescopic boom 3 are regulated by the limit value corrected in the step (1).

The boom height limiting device G configured as described above
The extension value of the telescopic boom 3 can be corrected for each extension or raising operation, and the extension or raising movement of the telescopic boom 3 can be regulated with a limit value suitable for the operation.

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

[0036]

[Effect of the Invention] The boom height limiting device of the working machine having the boom according to the present invention, which is constructed and operated as described above, has a structure in which the telescopic boom is raised when the telescopic boom is raised compared to when the telescopic boom is laid down. The extension movement is regulated with a limit value smaller than the limit value set by the setting device, so that the extension movement of the telescopic boom can be stopped with sufficient margin, and the tip of the telescopic boom can be applied to obstacles by overrun. You can prevent contact. 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 angle every 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 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. 5 is an explanatory diagram illustrating a mobile crane.

FIG. 6 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 arithmetic unit 11 setting unit 12 comparison unit 13 regulating means 13 ′ regulating means 14 correcting means 17 correcting means D boom height limiting device E boom height limiting device F Boom height limiter G Boom height limiter

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 extension movement of a telescopic boom based on the boom
A is, corrects the limit value as occupying become small the limiting value with increasing hoisting angle function of the telescopic boom seeking hoisting angle function of the telescopic boom obtained based on the detected value from the hoisting angle detector A boom height limiting device for a working machine having a boom, comprising a correction unit.