JP2003002585A - Device for holding suspension length of hook for crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a hook hoisting length in a prescribed length without providing an expansion number-of-stage detecting means in a crane of which expansion speeds of the boom 3 are different in accompaniment to expansion stages even when a switch-controlled variable of an expansion control valve 4 is same. SOLUTION: A controller 17 generates and outputs an expansion control valve controlling signal 17a for switch-controlling the expansion control valve 4 in response to an expansion control valve operation signal 14a, finds a switching direction and a reference switch-controlled variable f (14a) of a winch control valve 7 defined as a function of the expansion control valve operation signal 14a only, finds a corrected switch-controlled variable f (14a)+δS provided by correcting the reference switch-controlled variable f (14a) by a correction switch-controlled variable δS calculated based on a detection value by a boom length detecting means 15 and a detection value by a wire rope length detecting means 16, and generation-outputs a winch control valve control signal for switch- controlling the winch control valve 7 in response to the corrected switch- controlled variable f (14a)+δS.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hook hanging length holding device for holding a hook hanging length constant when a crane boom is extended and contracted. It is. 2. Description of the Related Art First, a crane to which a hook hanging length holding device of the present invention is attached will be described with reference to FIGS. FIG. 2 is an explanatory view of the entire configuration of the crane.
FIG. 3 shows a control circuit relating to the extension / retraction operation of the boom and the hoisting / lowering operation of the winch in the crane shown in FIG. [0004] As shown in FIGS. 2 and 3, the crane includes a swivel 2, which is slidably mounted on a base 1, a boom 3, which is slidably mounted on the swivel 2, and a telescopic control valve 4. First and second telescopic cylinders 5, 6, which extend and retract the boom 3 sequentially by the control oil
A winch 9 attached to a swivel 2 or a base end of a boom 3 which is operated by a winch motor 8 driven forward and reverse by control oil from a winch control valve 7;
A hook 11 suspended at the end of the boom 3 via a wire rope 10 pulled out from a winch 9 so as to be operable to perform a hoisting and lowering operation. 3 is the first telescopic cylinder 5
And the telescopic operation range of the second telescopic cylinder 6 are different from each other. [0005] Even if the switching control amount of the expansion and contraction control valve 4 is the same, the expansion and contraction speed of the boom 3 is different between the expansion and contraction operation range of the first expansion and contraction cylinder 5 and the expansion and contraction operation range of the second expansion and contraction cylinder 6. It is frequently used in vehicle-mounted cranes. Such a configuration will be described with reference to FIG. That is, the boom 3 is sequentially inserted into the boom section 3a on the proximal side and the boom section 3 on the distal side.
b, 3c, and 3d are inserted so as to be extendable and retractable, and a first telescopic cylinder 5 is mounted between the boom section 3a and the boom section 3b, and a second telescopic cylinder 6 is mounted between the boom section 3b and the boom section 3c. In addition, between the boom sections 3b, 3c, 3d, a wire simultaneous expansion / contraction means (not shown) for expanding / contracting the boom section 3d relative to the boom section 3c in conjunction with the expansion / contraction operation of the boom section 3c relative to the boom section 3b. Are placed. In this case, even if the effective pressure receiving areas of the extension operation side hydraulic oil chambers of the first and second telescopic cylinders 5 and 6 are the same, the expansion and contraction speed of the boom 3 is limited to the expansion and contraction operation range of the boom 3 by the first telescopic cylinder 5 ( The telescopic operation range of the second telescopic cylinder 6 (the telescopic operation range of the boom section 3d with respect to the boom section 3b) is twice as large as the telescopic operation range of the boom section 3b with respect to the boom section 3a. In FIG. 3, reference numeral 12 denotes a sequential telescopic control valve interposed between the telescopic control valve 4 and the first telescopic cylinder 5 and the second telescopic cylinder 6. When the first and second telescopic cylinders 5 and 6 are extended by the control oil of the telescopic control valve 4, the sequential telescopic control valve 12 operates to extend the second telescopic cylinder 6 after the first telescopic cylinder 5 is fully extended. When the first and second telescopic cylinders 5 and 6 are contracted, the control is performed so that the first telescopic cylinder 5 starts to be contracted after the second telescopic cylinder 6 has been contracted most. Next, a conventional example of a hook hanging length holding device attached to this type of crane will be described. A conventional hook suspension length holding device is described in, for example, Japanese Patent Application Laid-Open No. 2000-344472.
This hook suspension length holding device does not change the actual switching control amount of the expansion / contraction control valve 4 and the hook suspension length (the suspension distance of the hook 11 from the end of the boom 3) when the boom 3 is extended or retracted. Focusing on the fact that the boom 3 is in the telescopic operation range of the first and second telescopic cylinders 5 and 6, the relationship between the winch control valve 7 and the switching control amount of the winch control valve 7 is changed. The switching control amount is determined by the actual switching control amount of the telescopic control valve 4 and the detection result of the telescopic stage number detecting means for detecting which of the first and second telescopic cylinders 5 and 6 is in the telescopic operation range. I try to ask using. [0010] According to the conventional hook hanging length holding device constructed as described above, the relationship between the telescopic control valve 4 and the switching control amount of the winch control valve 7 is determined by the boom 3. Is maintained in a predetermined relationship (relation for keeping the hook suspension length constant regardless of the extension and retraction operation range of the boom 3) for each of the extension and retraction operation areas. However, since it does not detect the actual fluctuation of the hook suspension length and correct the switching control amount of the winch control valve, the hook suspension length is accurately maintained constant. There is a problem that it is difficult. There is also a problem that means for detecting the number of expansion / contraction steps is required. SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the above-mentioned conventional hook suspension length holding device, and to precisely maintain the hook suspension length constant and to extend and retract the hook suspension length. An object of the present invention is to provide a crane hook hanging length holding device that does not require a stage number detecting means. [0013] In order to achieve the above object, a hook hanging length holding device for a crane according to the present invention is configured as follows. A swivel 2 slidably mounted on the base 1, a boom 3 slidably mounted on the swivel 2, and expansion and contraction of the boom 3 by the control oil from the expansion control valve 4. First and second telescopic cylinders 5 and 6, which are operated, mounted on a swivel 2 or a base end of a boom 3 which is operated by a winch motor 8 driven forward and reverse by control oil from a winch control valve 7. A winch 9; and a hook 11 suspended from the winch 9 via a wire rope 10 at a tip end of the boom 3 so as to be able to perform a hoisting and lowering operation. The switching control amount of the telescopic control valve 4 is the same. Even so, the crane hook suspension length holding device is configured so that the extension / contraction speed of the boom 3 is different between the extension / contraction operation range by the first extension / contraction cylinder 5 and the extension / contraction operation region by the second telescopic cylinder 6. 13, telescopic operating means 14 for outputting a telescopic control valve operation signal 14a relating to the switching direction and amount of switching of the telescopic control valve 4, boom length detecting means 15 for detecting the length of the boom 3, wire A wire rope length detecting means 16 for detecting the feeding length of the rope 10; and a controller 17 for receiving a signal from each of these means and outputting a control signal for switching and controlling the telescopic control valve 4 and the winch control valve 7. The controller 17 generates (1) an expansion / contraction control valve control signal 17a for switching the expansion / contraction control valve 4 based on the switching direction and the switching amount indicated by the expansion / contraction control valve operation signal 14a. A valve control signal 17a is output to the telescopic control valve 4.
(2) The switching direction and the reference switching control amount f of the winch control valve 7 determined as a function of only the telescopic control valve operation signal 14a.
(14a) as well as the amount of change in the detection value of the boom length detection means 15 and the wire rope length detection means 16 after the reception of the telescopic control valve operation signal 14a.
A correction switching control amount δS of the winch control valve 7 necessary for making the detected value fluctuation amounts identical is determined, and the reference switching control amount f (14a) is corrected by the correction switching control amount δS. The amount f (14a) + δS is determined and the winch control valve 7 is moved in the switching direction determined as a function of only the telescopic control valve operation signal 14a.
Winch control valve control signal 17 for switching control at δS
b, and outputs the winch control valve control signal 17b to the winch control valve 7. A hook hanging length holding device for a crane, wherein the device is configured as described above. According to the hook hanging length holding device for a crane according to the present invention, the expansion and contraction control valve 4 is switched by the expansion and contraction operation means 14 in accordance with the above (1). The direction and the switching amount can be switched. At the same time, according to the above (2), the winch control valve 7 is switched to the switching direction and the switching amount of the winch control valve 7 necessary for keeping the hook hanging length constant. At this time, the switching direction of the winch control valve 7 is set to the lower side when the telescopic control valve 4 is switched to the extension side of the boom 3, and to the upper side when the telescopic control valve 4 is switched to the boom 3 reduction side. The switching control amount of the winch control valve 7 is changed from a reference switching control amount defined as a function of only the expansion / contraction control valve operation signal to a detection value of the boom length detection means after the reception of the expansion / contraction control valve operation signal. The changeover control amount can be switched to a correction changeover control amount obtained by correcting with the correction changeover control amount of the winch control valve 7 necessary for matching the fluctuation amount and the fluctuation amount of the detection value of the wire rope length detecting means. . In other words, the switching control amount of the winch control valve 7 is obtained by subtracting the reference switching control amount defined as a function of only the expansion / contraction control valve operation signal 14 (a function of only the switching control amount of the expansion / contraction control valve 4) from the boom. Correction (correction in the direction of reducing the actual fluctuation of the suspension length to zero) based on the fluctuation of the actual suspension length of the hook obtained by using the detection values of the length detection means and the wire rope length detection means as a medium. Thus, the modified switching control amount is obtained, and the winch control valve 7 is switched by the modified switching control amount. As described above, in the hook suspension length holding device of the present invention, the winch control valve 7 is controlled by the reference switching control amount determined according to the switching control amount of the telescopic control valve 4 to determine the actual hook suspension length. Since the switching control is performed with the corrected switching control amount corrected (corrected so that the fluctuation amount becomes zero) according to the fluctuation amount, the hook suspension length can be maintained extremely accurately. In addition, the hook hanging length holding device of the present invention configured as described above has an effect that the number of expansion / contraction step number detecting means is not required unlike the conventional hook hanging length holding device. The reference switching control amount is determined by the boom 3
Through the entire telescopic operation range (regardless of the telescopic operation range by the telescopic cylinder 5 or the telescopic operation range by the telescopic cylinder 6), the switching control amount of the telescopic control valve 4 is set with a certain relationship. The advantage of using the reference switching control amount is that the control amount of the winch control valve 7 is determined only by the actual fluctuation amount of the hook suspension length (the control amount of the winch control valve 7 is determined only by so-called feedback control). In comparison with this, the correction switching control amount (feedback control amount) can be set small, and smooth hook suspension length holding control can be performed. FIG. 1 is a block diagram showing a configuration of a hook hanging length holding device according to an embodiment of the present invention. As shown in FIG. 1, the hook suspension length holding device 13 according to the present invention comprises: a telescopic operation means 14 for outputting a telescopic control valve operation signal 14a relating to a switching direction and a switching amount of the telescopic control valve 4; A boom length detecting means 15 for detecting the length of the boom 3; a wire rope length detecting means 16 for detecting a feeding length of the wire rope 10; and a signal from each of these means is received and the expansion / contraction control is performed. And a controller 17 that outputs a control signal for controlling the switching of the valve 4 and the winch control valve 7. The boom length detecting means 15 continuously detects the separation distance between a proper position of the boom section 3a and the tip of the boom section 3d. A cord winder attached to the boom section 3a by winding and urging the cord fixed to the part so that it can be pulled out, and a cord winder attached to the cord winder to detect the amount of cord pulled out from the cord winder. It consists of a potentiometer. The wire rope length detecting means 16 comprises:
The detecting means continuously detects the feeding length of the wire rope 10 from the winch 9 and includes, for example, detecting means for detecting the rotation amount of the winch drum of the winch 9. The controller 17 includes a telescopic operating means 1
4, the detected boom length 15 a from the boom length detecting means 15, and the detected wire rope length 16 a from the wire rope length detecting means 16, and receive the following (1) and (2) ) Is performed. (1) An expansion / contraction control valve control signal 17a for switching the expansion / contraction control valve 4 is generated based on the switching direction and the switching amount indicated by the expansion / contraction control valve operation signal 14a. 4 is output. The calculation processing of (1) is performed by the controller 1
The control is performed by an expansion / contraction control valve control signal output unit 18 inherent in 7. Controller 17 (telescopic control valve control signal output unit 1
The telescopic control valve control signal 17a output by 8) is output to the telescopic control valve 4 (specifically, the switching drive means 4a of the telescopic control valve 4) and causes the telescopic control valve 4 to output the telescopic control valve operation signal 14a.
Is switched to the switching direction and the switching amount indicated by. (2) The switching direction and the reference switching control amount f of the winch control valve 7 determined as a function of only the telescopic control valve control signal 14a.
(14a) and the telescopic control valve operation signal 14a
The amount of change in the correction value of the winch control valve 7 required to match the amount of change in the detection value of the boom length detection means 15 and the amount of change in the detection value of the wire rope length detection means 16 after the receiving point δS, and further, a corrected switching control amount f (14a) + δS obtained by correcting the reference switching control amount f (14a) with the corrected switching control amount δS, and the winch control valve 7 is controlled by the telescopic control valve control signal. The modified switching control amount f (14) in the switching direction obtained as a function of only the
a) A winch control valve control signal 14b for switching control at + δS is generated, and the winch control valve control signal 14b is output to the winch control valve 7. The configuration of the controller for performing the operation (2) will be described below with reference to FIG. Reference numeral 19 denotes a reference switching control amount calculation unit that receives the expansion / contraction control valve operation signal 14a and calculates a reference switching control amount f (14a) of the winch control valve 7. The switching direction output by the reference switching control amount calculation unit 19 is the expansion / contraction control valve operation signal 1
When the switching direction of the telescopic control valve 4 indicated by 4a is the extension side of the boom 3, the winch control valve 7 is switched to the lower side, and when the switching direction of the expansion control valve 4 is the boom 3 reduction side, the winch control valve 7 is switched to the upper side. The reference switching control amount f (14a) output from the reference switching control amount calculation unit 19 is obtained as a function of only the switching control amount of the telescopic control valve 4 indicated by the telescopic control valve operation signal 14a. The values are the same in the operating range (regardless of whether the range is the telescopic operation range of the telescopic cylinder 5 or the telescopic cylinder 6). This reference switching control amount f (14a) is, for example,
When the telescopic operation range of the boom 3 is the telescopic operation range of the telescopic cylinder 6, “the switching control amount of the telescopic control valve 4 and the winch control valve 7 so as not to change the hook suspension length”
Relationship with Switching Control Amount ". Reference numeral 20 denotes an initial boom length storage unit for storing the detected boom length L0 of the boom length detection means 15 at the time of inputting the expansion / contraction control valve operation signal 14a. Reference numeral 21 denotes a time when the expansion / contraction control valve operation signal 14a is input. 5 is an initial wire rope length storage unit for storing the detected wire rope length S0 of the wire rope length detecting means 16 in FIG. Reference numeral 22 denotes a boom length variation for calculating a difference L-L0 between the initial boom length L0 stored in the initial boom length storage unit 20 and the boom length L actually detected by the boom length detection means 15. The amount calculating unit 23 stores the initial wire rope length S0 stored in the initial wire rope length storage unit 21.
And a wire rope length variation calculating unit for calculating a difference S-S0 between the wire rope length detection means 16 and the wire rope length S actually detected. Reference numeral 24 denotes the boom length variation calculating section 22
The correction switching for obtaining the correction switching control amount δS of the winch control valve 7 necessary for making the boom length fluctuation amount obtained in the above step coincide with the wire rope length fluctuation amount obtained by the wire rope length fluctuation calculating section 23. This is a control amount calculation unit. The reference numeral 25 denotes a correction for correcting the reference switching control amount f (14a) calculated by the reference switching control amount calculator 19 with the correction switching control amount δS to obtain a corrected switching control amount f (14a) + δS. It is a switching control amount calculation unit. 26 receives the modified switching control amount f (14a) + δS calculated by the modified switching control amount calculator 25, and switches the winch control valve 7 to the modified switching control amount f (14a) + δS related to the reception. Winch control valve control signal 17
It is a winch control valve control signal output / output unit that outputs b. The arithmetic processing of the above (2) in the controller 17 includes the above-described reference switching control amount calculation section 19, the initial boom length storage section 20, the initial wire rope length storage section 21, the boom length inherent in the controller 17. The change amount calculation unit 22, the wire rope length change amount calculation unit 23, the correction switching control amount calculation unit 24, the correction switching control amount calculation unit 25, and the winch control valve control signal output unit 26 are used. The winch control valve control signal 17 output by the controller 17 (the winch control valve control signal output section 26)
b is output to the winch control valve 7 (specifically, the switching drive means 7a of the winch control valve 7),
Is switched to the switching direction and the switching amount indicated by the winch control valve control signal 17b. In the above embodiment, the reference switching control amount f (14a) is obtained as a function of only the expansion / contraction control valve operation signal 14a. Since it is determined as a function of only the switching control amount 14a, it may be obtained as a function of only the switching control amount of the telescopic control valve 4.
(14a) has the same meaning as being obtained as a function of only the expansion / contraction control valve operation signal 14a. According to the hook suspension length holding device of the present invention configured as described above, the winch control valve 7 is controlled by the reference switching control amount f (14a) determined according to the switching control amount of the telescopic control valve 4. Is controlled by the modified switching control amount f (14a) + δS, which is corrected (corrected so that the fluctuation amount becomes zero) by the actual fluctuation amount of the hook suspension length. It can be held accurately. Moreover, the hook suspension length holding device 13 of the present invention configured as described above includes:
There is an effect that the number of expansion / contraction stages detecting means is not required unlike the conventional hook hanging length holding device. The reference switching control amount f (14a) is
The entire telescopic operation range of the boom 3 (regardless of whether it is the telescopic operation region by the telescopic cylinder 5 or the telescopic operation region by the telescopic cylinder 6)
Through the above, it is set with a certain relationship with the switching control amount of the expansion / contraction control valve 4. This reference switching control amount f (14
The advantage of using a) is that the control amount of the winch control valve 7 is determined only by the actual fluctuation amount of the hook suspension length (the control amount of the winch control valve 7 is determined only by so-called feedback control). The point is that the correction switching control amount δS (feedback control amount) can be set small, and smooth hook suspension length holding control can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a hook hanging length holding device of a crane according to the present invention. FIG. 2 is an explanatory view of a crane to which the hook hanging length holding device of the present invention is attached. FIG. 3 is an explanatory diagram of a control circuit related to a boom extension / retraction operation and a winch hoisting / lowering operation of the crane of FIG. 2; DESCRIPTION OF SYMBOLS 1; Base, 2; Swivel, 3; Boom, 4; Telescopic control valve, 4a; Switching drive means, 5; First telescopic cylinder, 6; Second telescopic cylinder, 7; Winch control valve 7a; switching drive means, 8; winch motor, 9; winch, 10; wire rope, 11; hook, 12; sequential telescopic control valve, 13; hook hanging length holding device, 14; telescopic operating means, 14a; Telescopic control valve operation signal, 15; boom length detecting means, 16; wire rope length detecting means, 17; controller, 18; telescopic control valve control signal output section, 19; reference switching control amount calculating section, f (14a) Reference switching control amount; 20; initial boom length storage unit; 21; initial wire rope length storage unit; 22; boom length variation calculation unit; 23; wire rope length variation calculation unit; Control amount calculating section, delta] S; correction switching control amount, 25; corrected switching control amount calculating section, f (14a) + δS; modified switch control amount, 26; winch control valve control signal output section, or

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hideyuki Sasaki             153 Yashimanakamachi, Takamatsu City, Kagawa Prefecture F term (reference) 3F205 AA05 CA03 CB02 DA04 HA01                       HA10 HB10

Claims (1)

1. A swivel 2 attached to a base 1 so as to be able to swing freely, a boom 3 attached to the swivel 2 so as to be able to move up and down, and expansion and contraction by control oil from an expansion and contraction control valve 4 sequentially. First and second telescopic cylinders 5 and 6 that operate to extend and retract the boom 3, and a swivel 2 or a boom that performs a hoisting and lowering operation with a winch motor 8 driven forward and reverse by control oil from a winch control valve 7. A telescopic control valve, comprising: a winch 9 attached to a base end of the boom 3; and a hook 11 operably suspended at a tip end of the boom 3 via a wire rope 10 drawn from the winch 9. 4, even if the switching control amount of the boom 3 is the same, the extension / retraction speed of the boom 3 is different between the telescopic operation range of the first telescopic cylinder 5 and the telescopic operation range of the second telescopic cylinder 6. A telescopic operation means 14 for outputting a telescopic control valve operation signal 14a relating to a switching direction and a switching amount of the telescopic control valve 4; a boom length for detecting the length of the boom 3 A wire rope length detecting means 16 for detecting the feeding length of the wire rope 10, and a signal from each of these means is received and the switching of the telescopic control valve 4 and the winch control valve 7 is controlled. The controller 17 outputs a control signal. The controller 17 includes: (1) an expansion / contraction control valve control signal 17a for switching the expansion / contraction control valve 4 based on the switching direction and the switching amount indicated by the expansion / contraction control valve operation signal 14a. And outputs the expansion / contraction control valve control signal 17a to the expansion / contraction control valve 4.
(2) The switching direction and the reference switching control amount f of the winch control valve 7 determined as a function of only the telescopic control valve operation signal 14a.
(14a) as well as the amount of change in the detection value of the boom length detection means 15 and the wire rope length detection means 16 after the time of receiving the telescopic control valve operation signal 14a.
A correction switching control amount δS of the winch control valve 7 necessary for making the detected value fluctuation amounts identical is determined, and the reference switching control amount f (14a) is corrected by the correction switching control amount δS. The amount f (14a) + δS is determined, and the winch control valve 7 is moved in the switching direction determined as a function of only the telescopic control valve operation signal 14a.
Winch control valve control signal 17 for switching control at δS
b, and outputs the winch control valve control signal 17b to the winch control valve 7. A hook hanging length holding device for a crane, wherein the device is configured as described above.