JP2003192276A - Expansion and contraction control device for telescopic boom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of a conventional telescopic boom for expanding and contracting a multi-step boom step by step with a telescopic cylinder which takes a long time to expand and contract when making its telescopic condition as desired and, on the other hand, whose cylinder boom engaging mechanism 20 and a between-boom connection mechanism 50 do not securely work when the expansion and contraction speed is raised. <P>SOLUTION: This expansion and contraction control device for a telescopic boom has a plurality of control valves 103a and 103b for control-driving the telescopic cylinder 1 so that hydraulic pressure can be supplied to the telescopic cylinder 1 from the plurality of control valves. A controller 65 is equipped with a neighborhood judging means 65a for judging that the telescopic boom 1 is in the neighborhood of the position where the cylinder boom engaging mechanism 20 or the between-boom connection mechanism 50 operates and a control valve output means 65b for outputting a predetermined operation volume to a single control valve 103a when the neighborhood judging means 65a is in the neighborhood. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic boom telescopic control device which telescopically expands and retracts the boom stages constituting a multi-stage telescopic boom by one telescopic cylinder.

[0002]

2. Description of the Related Art As a telescopic mechanism for a multi-stage telescopic boom of a vehicle-mounted crane, an telescopic mechanism has been put into practical use in which a boom stage to be telescopically driven by one telescopic cylinder is telescopically driven. Since this telescopic mechanism has only one telescopic cylinder, it has the advantage that the weight of the entire telescopic mechanism can be reduced.

In this telescopic mechanism, one telescopic cylinder is incorporated in the telescopic boom, and the rod end portion is pivotally supported by the base boom base end portion. The telescopic mechanism has a cylinder / boom engagement / disengagement mechanism and a boom-to-boom coupling mechanism.

The cylinder / boom engagement / disengagement mechanism is arranged at the rod-side end of the cylinder tube of the telescopic cylinder, and by moving the built-in connecting pin back and forth toward the connecting hole at the base end of the desired boom. It is possible to selectively connect and disconnect with the boom base end.

The boom-to-boom connecting mechanism is arranged at the inner boom base end portion of the adjacent booms, and by advancing and retracting a built-in fixing pin toward a fixing hole provided at a proper position of the outer boom, the adjacent booms are connected to each other. Can be fixed and released.

The boom-to-boom connecting mechanism is arranged at the end of the telescopic cylinder on the side of the cylinder tube rod, and acts on the inner end of the fixed pin at the base end of the boom to drive the fixed pin drive means. Is equipped with.

Then, the cylinder / boom engaging / disengaging mechanism connects the telescopic cylinder to the desired boom base end, and the fixing pin driving means of the boom-to-boom connecting mechanism retracts the fixing pin. A boom-to-boom fixation releasing process for releasing the fixation between the target boom and the outer boom, a target boom extending and retracting process for extending and retracting the target boom by the telescopic cylinder, and a target boom and the outer boom by the fixing pin drive means by the boom-to-boom coupling mechanism. A boom-to-boom fixing step, a cylinder / boom connection releasing step for releasing the connection between the telescopic cylinder and the target boom base end portion by the cylinder / boom connecting means, and the telescopic cylinder provides the following target boom base end The telescopic cylinder telescopic stroke that extends and contracts up to It performs a contraction.

[0008]

By the way, since the above-mentioned telescopic mechanism drives the boom stage to be telescopically driven by one telescopic cylinder one by one, the telescopic cylinder of the telescopic cylinder can be moved during the above-mentioned telescopic stroke. The time required for the expansion and contraction process was generated, and the total time required for the entire expansion and contraction boom to reach the desired expansion and contraction state was long. Therefore, if the expansion / contraction speed is increased when the expansion / contraction boom is expanded / contracted, the cylinder / boom connecting / disconnecting mechanism connects the expansion / contraction cylinder to the target boom base end portion by the cylinder / boom engagement / disengagement mechanism, and the fixing pin drive. In the boom-to-boom fixing process of fixing the target boom and the outer boom by the boom-to-boom connecting mechanism by means, there is a problem that the expansion and contraction speed of the telescopic cylinder is high, so that the connection cannot be surely performed in each of the steps.

The present invention provides a telescopic boom telescopic control device capable of shortening the total time required to bring the telescopic boom to the intended telescopic state and reliably connecting the cylinder / boom coupling stroke and the boom fixed stroke. It is the one we are trying to provide.

[0010]

According to the invention of the telescopic boom telescopic control device of the present invention described in claim 1, each telescopic boom is composed of a multi-stage boom which is sequentially telescopically inserted. A telescopic cylinder that alternately expands and contracts with a cylinder, a control valve that supplies hydraulic pressure from a hydraulic source to the telescopic cylinder to control and drive the telescopic cylinder, and a cylinder / boom engagement / disengagement mechanism that engages / disengages the telescopic boom and each boom stage. , A boom-to-boom connection mechanism for connecting and disconnecting adjacent boom stages, a telescopic boom state detecting means for detecting a boom state of the telescopic boom, and an operation direction and an operation amount which are operated when the telescopic boom is extended and retracted. When the telescopic boom is extended by receiving the signals from the operation instruction means, the operation instruction means and the telescopic boom state detection means, Is a telescopic boom telescopic control device including a control valve, a cylinder / boom engagement / disengagement mechanism, and a controller that appropriately outputs a signal for operating the boom-to-boom coupling mechanism so as to be retracted from the proximal boom stage. A plurality of control valves are arranged so that hydraulic pressure can be supplied to and discharged from the telescopic cylinders through the plurality of control valves, and the controller receives a detection signal from the telescopic boom state detection means to determine the telescopic boom state by the cylinder / boom engagement / disengagement mechanism. Alternatively, a proximity determining means for determining that the boom interlocking mechanism is in the vicinity of operation and a control valve output means for outputting a predetermined operation amount to a single control valve when the proximity determining means is in the vicinity. It is characterized by having.

According to a second aspect of the present invention, there is provided an extension / contraction control device for an extension / contraction boom according to the first aspect of the present invention. In the first aspect, the extension / reduction control device switches the operation mode between a high speed mode for operating the extension cylinder at a high speed and a low speed mode for operating the extension cylinder at a low speed. The controller comprises means for supplying a hydraulic pressure from a plurality of control valves to the telescopic cylinder when the operation mode switching means is switched to the high speed mode, and a single control to the telescopic cylinder when the operation mode switching means is switched to the low speed mode. The present invention is characterized by comprising control valve switching output means for supplying hydraulic pressure from a valve and priority means for outputting the control valve output means with priority over the control valve switching output means.

A telescopic boom extension / contraction control device invention according to a third aspect of the present invention is the extension / boom extension / contraction control device invention according to the first or second aspect, wherein the controller outputs the output from the control valve output means and the operation command means. It is characterized by comprising a comparison means for outputting the smaller output signal to the control valve based on the manipulated variable signal to the control valve. A telescopic boom extension / contraction control device invention according to a fourth aspect of the present invention is the extension / contraction control device invention of the first to third aspects, wherein the plurality of control valves are configured by a first control valve and a second control valve, and Has a control valve actuation order means for actuating the first control valve to an arbitrary position first and then actuating the second control valve when the telescopic cylinder is driven and controlled by the plurality of control valves. It is characterized by.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Telescopic machine with one telescopic cylinder
Configuration of Structure FIG. 1 is a cross-sectional view taken along the telescopic cylinder of a six-stage telescopic boom in which an telescopic mechanism including one telescopic cylinder is used, and shows a base end portion in a fully contracted state. Telescopic boom 10
Inside the base boom 11, the second boom 12, the third boom 13, the force boom 14, the fifth boom 1
5 and the top boom 16 are each telescopically inserted. Reference numeral 1 denotes a telescopic cylinder, which includes a cylinder tube 2, a cylinder tube rod side end portion 3,
It is composed of a rod 4 and a rod end portion 5. The telescopic cylinder 1 is installed inside the telescopic boom 10, and the telescopic cylinder rod end 5 is pivotally supported by the base boom base end 11 a of the base boom 11. Below, 1
The main configuration of the expansion / contraction mechanism using the expansion / contraction cylinder of the book will be described. (Cylinder / boom engagement / disengagement mechanism) FIG. 2 is a sectional view taken along line AA of FIG. 20 is a cylinder / boom engagement / disengagement mechanism,
Cylinder tube rod end 3 of the telescopic cylinder 1
Connecting pin drive cylinder 21, connecting pin drive lever 22, connecting pin 23, and connecting hole 16b of the connecting boss 16c arranged at the top boom base end 16a.
It consists of The connecting pin 23 is slidably assembled in the connecting pin receiving hole 26 of the trunnion member 25 that constitutes the end portion 3 of the telescopic cylinder rod side. The connecting pin drive lever 22 is pivotally supported from the trunnion member 25 to a support 24 integrally formed above. In FIG. 2, the connection hole 16b is the base boom base end portion 1
Although only those provided on 6a are shown, as indicated by the chain double-dashed line in FIG. 1, the second boom base end 12a, the third boom base end 13a, the force boom base end 14a, the fifth boom base end 15a, Similarly for each connection hole 1
2b, 13b, 14b, 15b are provided.

The connecting pin 23 and the connecting pin drive lever 2
A pair of 2 is arranged on the left and right. Connecting pin drive lever 2
One end of 2 is pivotally attached to the connecting pin 23, and the other end is pivotally attached to the rod end 21a and the cylinder end 21b of the connecting pin drive cylinder 21, respectively. (Boom-to-boom connection mechanism) 50 shown in FIG. 2 is the top boom 1.
6 is a boom-to-boom connecting mechanism, which is a top boom base end portion 1
The top boom fixing pin 16d and the fifth boom 15 slidably assembled to the fixing pin housing member 16e of 6a.
Fixing hole 5 provided in the fixing boss 52 attached to the side surface of the
1 and a fixed pin driving means 40 described later. Reference numeral 33 is a connecting member provided at the inner end of the top boom fixing pin 16d. The connecting member 33 has a box shape with a part of the opening, and can be connected to a fixed pin drive lever of a fixed pin drive means described later. As shown in FIG. 2, a pair of top boom fixing pins 16d are arranged on the left and right. Similarly, the second boom fixing pin 12d, the third boom fixing pin 13d, and the force are similarly applied to the second boom base end 12a, the third boom base end 13a, the force boom base end 14a, and the fifth boom base end 15a (not shown), respectively. Boom fixing pin 14d,
A pair of fifth boom fixing pins 15d are arranged on the left and right.

In addition to the fixing boss 52 attached to the side surface of the fifth boom described above, a plurality of fixing bosses are arranged on the side surface of the fifth boom in the longitudinal direction according to the extension length of the top boom 16. Each fixing boss has a fixing hole. Regarding the arrangement of the fixed boss, the base boom 11, the second boom 12, the third boom 1
3. The force boom 14 has almost the same configuration.

FIG. 3 is a view taken along the line BB of FIG. Reference numeral 34 is a ball lock mechanism of the fixing pin 16d. A notch 36 is formed in the fixing pin 16d, and the spring-biased ball 35 of the ball lock mechanism 34 is notched by the notch 36.
By being fitted into the fixing pin 16d, the end portion 53 of the fixing pin 16d is held at the fixed position between the booms where the fixing pin 16d enters the fixing hole 51 of the outer boom. (Fixed Pin Driving Means) Reference numeral 40 shown in FIG. 3 is a fixed pin driving means, which is composed of a fixed pin driving cylinder 41, a fixed pin driving lever 42, and a roller 44. The fixed pin drive levers 42 are pivotally supported by a support 45 formed integrally with the end portion 3 of the telescopic cylinder 1 on the cylinder tube rod side, and are arranged in a pair on the left and right.
A roller 44 is rotatably supported at one end of the fixed pin drive lever 42, and the other end thereof has a rod side end portion 41a and a cylinder side end portion 4 of the fixed pin drive cylinder 41.
1b are respectively pivoted.

The fixed pin drive means 40 is entirely integrated with the end portion 3 of the telescopic cylinder 1 on the cylinder tube rod side. Therefore, the fixing pins 12d to 16 of the boom connecting mechanism 50 and the like of the top boom 16 arranged at the base end of each stage boom due to the expansion and contraction operation of the expansion and contraction cylinder 1.
The roller 44 can be positioned in the connecting member 33 of any fixed pin of d, and the fixed pin can be driven. At that time, when the telescopic cylinder 1 extends and contracts, the connecting member 33 provided at the inner end of the fixing pin has a box-like shape with an opening.
The fixing pin drive lever 42 can pass through the opening portion of the connecting member 33 of the fixing pin which is not intended. Configuration of Control Device for Telescopic Mechanism FIG. 4 shows a block diagram and a hydraulic circuit diagram of the telescopic boom telescopic control device according to the embodiment of the present invention. (Expansion / contraction mechanism operating means) 60 is an expansion / contraction mechanism operating means, and includes an expansion / contraction operating lever 61 (corresponding to the operation commanding means according to claim 1), an operation mode switching means 62, a final boom state input means 63, and expansion / contraction related means. The information display means 70 and the information display means 70 are arranged in a crane operating room (not shown). The expansion / contraction operation lever 61 converts an operation direction and an operation amount of the expansion / contraction operation lever into an electric signal and outputs the electric signal to the controller 65. The operation mode switching means 62 is a means for manually switching between expansion and contraction of the telescopic cylinder 1 to be described later at high speed and expansion and contraction at low speed. The operation mode switching means 62 is composed of a switching operation switch, and is switched from the operation mode switching means 62. The signal is input to the controller 65. The final boom state input means 63 is for inputting the final boom state when the telescopic boom 10 is telescopically extended by the telescopic mechanism.
It is operated integrally with the expansion / contraction related information display means 70 described later. The operation signal of the final boom state input means 63 is also output to the controller 65. The expansion / contraction related information display means 70 graphically displays information related to the operation of the expansion / contraction mechanism in response to a signal from the controller 65.

The expansion / contraction related information display means 70 can switch the display contents, and FIG. 5 shows a display screen by the expansion / contraction related information display means 70. A plurality of extension lengths 71 of telescopic booms and boom extension ratios 72 of each stage of booms indicating the boom condition are displayed, and the box-shaped cursor 73 can be moved up and down by the feed / return key included in the final boom state input means 63. It is like this. When the set key included in the final boom state input means 63 is operated after moving the box-shaped cursor 73 to the line of the desired boom condition, the final boom state of the desired telescopic boom is input to the controller 65. be able to.
The selected last boom state is indicated by the circle mark 74. (Extendable boom state detecting means) 75 is an extendable boom state detecting means, and is composed of the following detecting means. That is, reference numeral 80 denotes a boom base end position detecting means, which detects which boom the base end position of the cylinder / boom engagement / disengagement mechanism 20 is located, and outputs the signal to the controller 65. . Reference numeral 90 denotes a cylinder length detecting means, which detects the cylinder length of the telescopic cylinder 1 and outputs a signal thereof to the controller 65. Reference numeral 110 denotes a connecting pin state detecting means for detecting the state of the connecting pin driven by the cylinder / boom engagement / disengagement mechanism 20 and outputting the signal to the controller 65. A fixed pin state detection unit 120 detects the state of the fixed pin driven by the fixed pin drive unit 40 and outputs a signal thereof to the controller 6
5 is output. The controller 65 reads out the specified expansion / contraction length determined by the stored position of the fixing hole of the inter-boom fixing mechanism based on the detected value of the cylinder length detecting means 90 and the fixed pin state detecting means 120, and The specified extension / contraction length is the extension / contraction length in the boom extension / contraction process.

FIG. 6 shows the boom base end position detecting means 80.
It is a specific example of FIG. 2, and is a DD arrow view of FIG. Proximity switches 82 to 86 are attached to the trunnion 25 located at the end portion 3 of the telescopic cylinder 1 on the cylinder tube rod side via the supports 81, 81. 1
6f is a detection piece attached to the base boom base end portion 16a. FIG. 6 shows a state in which the proximity switch 86 detects the detection piece 16f of the top boom base end portion 16a. Similarly, the proximity switch 82 is also attached to the other boom base end.
The detection pieces 12f to 15f are provided at positions corresponding to .about.85, and the proximity switches 82 to 85 detect the detection pieces, respectively. With this configuration,
Depending on which proximity switch detects the detection piece, it is possible to determine which boom the connection pin 23 of the cylinder / boom connection means 20 is located in the connection hole of the base end portion of the boom.

FIG. 1 shows a state in which the cylinder length detecting means 90 is attached to the telescopic boom 10.
The cylinder length detecting means 90 is the base boom base end portion 11a.
The cord 91 pulled out from the length detector 95 is connected to the support 94 of the end portion 3 on the cylinder tube rod side of the telescopic cylinder 1 through the guide rollers 92 and 93. The cord 91 is moved in and out of the length detector 95 as the telescopic cylinder 1 extends and contracts, and the length of the telescopic cylinder 1 is detected by the amount of the cord 91 pulled out. ing.

FIG. 7 is a view taken in the direction of arrows CC in FIG. 2, showing the details of the connecting pin state detecting means 110. Reference numerals 112 and 113 are proximity switches attached to the cylinder portion of the connecting pin driving cylinder 21.
Is a U-shaped detection piece attached to the rod portion of the connecting pin drive cylinder 21. In FIG. 2, the connecting pin 23 of the cylinder / boom engaging / disengaging mechanism 20 is connected to the connecting hole 1 of the top boom 16.
The cylinder and boom are in the 6b connection state,
At this time, the one proximity switch 112 causes the detection piece 11 to move.
1 is detected. When the connecting pin drive cylinder 21 is driven and the tip of the connecting pin 23 comes out of the connecting hole 16b, the other proximity switch 113 detects the detection piece 111.

Reference numeral 120 in FIG. 3 shows a specific example of the fixed pin state detecting means. 122 and 123 are proximity switches attached to the cylinder portion of the fixed pin drive cylinder 41, and 121 is a U-shaped detection piece attached to the rod portion of the connection pin drive cylinder 41. FIG. 3 shows a state in which the tip portion 53 of the fixing pin 16d of the top boom base end portion 16a is released from the fixing hole 51 of the fifth boom 15 between the booms, and at this time, the one proximity switch 123 detects the detection piece. 121 is detected. The fixed pin drive cylinder 41 is driven,
When the tip 53 of the fixing pin 16d enters the fixing hole 51, the other proximity switch 122 detects the detection piece 121. (Drive hydraulic pressure supply means) 100 in FIG. 4 is a drive hydraulic pressure supply means, which receives a signal from the controller 65,
The expansion / contraction mechanism 1, the cylinder / boom engagement / disengagement mechanism 20, and the fixed pin drive means 40 of the boom-to-boom connection mechanism 50 that constitute the expansion / contraction mechanism are driven.

FIG. 4 shows an example of a concrete hydraulic circuit which constitutes the driving hydraulic pressure supply means 100, and is constituted as follows. The telescopic cylinder 1 includes a first control valve 103
a (composed of pilot type switching valve) and second control valve 103b
The two control valves (composed of pilot type switching valves) are used to control the first hydraulic pump 105a and the second hydraulic pump 105, respectively.
The expansion and contraction drive is controlled by the hydraulic pressure from b. 10
4a and 104b are the first control valve 103a and the second control valve 1
03b and the telescopic cylinder 1 are provided on the respective oil supply / discharge passages. Reference numerals 101a, 101b and 102a, 102b are electromagnetic proportional valves that send pilot pressure to switch the respective control valves (pilot type switching valves) 103a, 103b. The solenoid proportional valve 1
01a, 101b and the solenoid proportional valves 102a, 102b are proportionally controlled by signals from the controller 65. 109a and 106a are the first
A flow control valve and a relief valve arranged between the hydraulic pump 105a and the first control valve 103a. 109b and 106b
Is a flow control valve and a relief valve arranged between the second hydraulic pump 105b and the second control valve 103b.

The connecting pin drive cylinder 21 and the fixed pin drive cylinder 41 are respectively connected to the solenoid switching valve 10
Connected to the oil pressure source and the tank via 7, 108,
The solenoid switching valves 107 and 108 are the controller 6
Switching operation is performed by a signal from 5. (Operation of Controller) As shown in FIG. 9, the controller 65 receives a detection signal from the telescopic boom state detection means 75 and determines the state of the telescopic boom 1 to be the cylinder / boom engagement / disengagement mechanism 20 or the boom coupling mechanism 50. Proximity determining means 60a for determining that the operation is in the vicinity,
When the proximity determining means 60a determines that the first control valve 103a is in the vicinity, the predetermined operation amount of the first control valve 103a is set in advance (here, the predetermined operation amount is reliably determined by the cylinder / boom engagement / disengagement mechanism 20 or the boom coupling mechanism 50). The control valve output means 65b and the operation mode switching means 62 are operated to operate the telescopic cylinder 1 at a very low speed.
Is switched to the high speed mode, the telescopic cylinder 1 is supplied with and discharged from the first control valve 103a and the second control valve 103b, and when the operation mode switching means 62 is switched to the low speed mode, the telescopic cylinder 1 is transferred from the first control valve 103a. Control valve switching output means 65c for supplying and discharging hydraulic pressure, and control valve output means 65
Priority output 65d for giving priority to the control valve switching output means 65c, output from the control valve output means 65b, and output to the control valve based on the operation amount signal from the operation lever (operation command means) 61. When the expansion cylinder 1 is driven and controlled by the comparison means 65e for outputting the smaller output signal of the control valve to the control valve, and the first control valve 103a and the second control valve 103b, the first control valve 103a is set to the maximum first. Control valve actuation order means 65 for actuating and then actuating the second control valve 103b
f and.

The control valve output means 65b, when the operation mode switching means 62 is switched to the high speed mode, is shown in FIG.
As shown in the figure, the operation lever (operation command means) 61
Manipulated variable signal from the first control valve 103a and the second control valve 1
When the telescopic cylinder 1 is operated in accordance with the flow rate of 03b and the operation mode switching means 62 is switched to the low speed mode, the operation amount signal from the operation lever (operation command means) 61 as shown in FIG. The telescopic cylinder 1 is operated according to the flow rate of the first control valve 103a.

The operation signals to the first control valve 101a and the second control valve 101b are output as shown in the flow chart shown in FIG. The function of the controller 65 will be described below with reference to FIG. In the flowchart of FIG. 9, the function of discriminating the operation direction of the operation lever (operation command means) 61 is omitted. First, step 1
Receives a signal from the operation lever (operation command means) 61 and reads the operation amount. In step 2, the state of the telescopic boom is read in response to the signal from the telescopic boom state detecting means 75. In step 3, the operation mode set by the signal from the operation mode switching means 62 is read.

Next, in step 4, depending on the state of the telescopic boom read in step 2, it is determined whether or not the state of the telescopic boom is in the vicinity where the cylinder / boom engagement / disengagement mechanism 20 or the boom-to-boom connection mechanism 50 operates. Make a distinction.
If it is determined to be in the vicinity, the process proceeds to step 5 and step 5
Then, it is determined whether or not the operation amount read in step 1 reaches a preset predetermined operation amount. Here, the predetermined operation amount is an operation amount for slightly expanding and contracting the telescopic cylinder 1 so that the cylinder / boom engagement / disengagement mechanism 20 or the boom-to-boom connection mechanism 50 can be reliably performed.

If the operation amount ≧ the predetermined operation amount, the routine proceeds to step 6, where a signal is output from the controller 65 to the electromagnetic proportional control valve 101a or the electromagnetic proportional control valve 102a so that the telescopic cylinder 1 expands and contracts at a predetermined minute speed, and the first Control valve 103a
Operate. If the operation amount <the predetermined operation amount, step 7
Then, the controller 65 outputs a signal to the electromagnetic proportional control valve 101a or the electromagnetic proportional control valve 102a so that the telescopic cylinder 1 expands and contracts by the operation amount read in step 1, and operates the first control valve 103a.

In this way, when the controller 65 determines in step 4 that it is in the vicinity, the first control valve 103a is operated in step 6 or step 7, and step 4 is the proximity determining means according to claim 1. And step 6 or step 7 corresponds to the control valve output means according to claim 1. If the operation amount is greater than or equal to the predetermined operation amount in step 5, the first control valve 103a is operated by the predetermined operation amount in step 6, and if the operation amount is less than the predetermined operation amount in step 5, the first control is performed in step 7. The valve 103a is operated by the manipulated variable. That is, the smaller one of the operation amount and the predetermined operation amount is used to operate the first control valve 103a, which constitutes the comparison means of claim 3.

Next, when it is judged in step 4 that the operation mode is not in the vicinity, the process proceeds to step 8, and in step 8, it is judged whether or not the operation mode read in step 3 is set to the low speed mode. If the low speed mode is set, the process proceeds to step 9. In step 9, whether or not the operation amount read in step 1 has reached the operation amount for maximally operating the first control valve 103a (operation amount ≧ first control Maximum valve operation amount)
To determine. If the operation amount ≧ the first operation amount of the first control valve, the routine proceeds to step 10, where a signal is output from the controller 65 to the electromagnetic proportional control valve 101a or the electromagnetic proportional control valve 102a so as to maximize the operation of the first control valve 103a. Therefore, the telescopic cylinder 1 telescopes at the speed at which the first control valve 103a is operated to the maximum.

If the manipulated variable is smaller than the maximum manipulated variable of the first control valve in step 9, the process proceeds to step 7, and the telescopic cylinder 1 is expanded and contracted by the manipulated variable read in step 1.
01a or the solenoid proportional control valve 102a to the controller 6
A signal is output from 5 to operate the first control valve 103a.

If it is determined in step 8 that the low speed mode is not set, the process proceeds to step 11 and step 1
1, the operation amount read in step 1 is the first control valve 103
It is determined whether or not the operation amount for maximally operating a is reached. If the operation amount in step 11 <the maximum operation amount of the first control valve, the process proceeds to step 7, and the expansion / contraction cylinder 1 is expanded / contracted by the operation amount read in step 1 so that the electromagnetic proportional control valve 1
01a or the solenoid proportional control valve 102a to the controller 6
A signal is output from 5 to operate the first control valve 103a.

If the operation amount ≧ the first control valve maximum operation amount in step 11, the process proceeds to step 12, and the first control valve output is the maximum operation amount output (first control valve output = maximum operation amount output). Make a decision. When it is determined in step 12 that the first control valve output is equal to the maximum manipulated variable output, the process proceeds to step 13 and the electromagnetic proportional control valve 101a or the electromagnetic proportional control valve 102 is operated so as to operate the first control valve 103a to the maximum.
In addition to outputting a signal from the controller 65 to a, the first control valve maximum operation amount is subtracted from the operation amount read in step 1 and the second control is performed with the remaining operation amount (operation amount-first control valve maximum operation amount). A signal is output from the controller 65 to the electromagnetic proportional control valve 101b or the electromagnetic proportional control valve 102b so as to operate the valve 103b. Therefore, telescopic cylinder 1
The expansion and contraction is controlled by the first control valve 103a and the second control valve 103b to increase and decrease the expansion and contraction speed.

When it is judged in step 12 that the first control valve output is not equal to the maximum manipulated variable output, the routine proceeds to step 14, where the first control valve output
A signal is output from the controller 65 to the electromagnetic proportional control valve 101a or the electromagnetic proportional control valve 102a so that the control valve 103a quickly reaches the maximum operation amount, and the first control valve 103a is operated.

In this way, the controller 65 operates the first control valve 103a in step 7 or step 10 when it is determined that the speed is low in step 8, and when it determines that the speed is not low in step 8, step 13
The first control valve 103a and the second control valve 103b are used to extend and retract the telescopic cylinder 1, and these steps constitute the control valve switching means.
In step 14, only the first control valve 103a is operated, but in step 14, the first control valve 103a is operated.
03a to the maximum operation amount, and then the second control valve 10
It is only a process for activating 3b.

Further, prior to step 8, the discrimination in step 4 is prioritized, but this is prioritized in the proximity discrimination rather than the operation mode switching. That is, it constitutes the priority means according to claim 2 that prioritizes the control valve output means over the control valve switching output means.

Further, in step 12, the first control valve 103a
Is not the maximum operation, the first control valve 103a is operated in step 14 until the maximum operation is performed, and when the first control valve 103a is the maximum operation, the second control valve 103b is operated in step 13. I am trying to make it work. That is, when the telescopic cylinder 1 is drive-controlled by the plurality of control valves according to claim 4, the first control valve 103a is used.
Is first operated to the maximum, and then the second control valve 103b is operated, which constitutes a control valve operating sequence means.

Operation of the telescopic mechanism by the controller From the fully contracted state of the 6-step telescopic boom 10 shown in FIG.
Corresponding to the extension operation of the telescopic mechanism until the top boom 16 and the fifth boom 15 shown in FIG.
The control content of the telescopic boom telescopic control device of the present invention will be described. (Boom condition setting) It is assumed that the telescopic boom 10 is in the fully contracted state and the undulation angle is the maximum undulation angle. At this time,
As shown in FIG. 7, the cylinder / boom engagement / disengagement mechanism 20 is in a connected state with the base end portion 16b of the top boom 16, and all the boom-to-boom fixing means of each stage boom are in a fixed state. The boom condition is selected on the display screen of the expansion / contraction related information display means 70 shown in FIG. 5 by the feed / return key included in the final boom state input means 63. Now, suppose the top boom (6th step) grew 93% and the fifth boom (5th step) was 93%.
Suppose you have selected the No. 5 boom condition, which will increase%. When the set key included in the final boom state input means 63 is operated, the selected boom condition is output to the controller 65 and stored in the controller 65. Next, the expansion / contraction operation lever 61 is operated to the maximum extension side, and the operation mode switching means 62
Set to high speed mode. As long as the extension / contraction operation lever 61 is continuously operated toward the extension side, the controller 65 thereafter automatically controls the extension / contraction mechanism, repeats the extension / contraction mechanism cycle, and continues the extension / contraction operation until the boom condition set above is satisfied. When the extension / contraction operation lever 61 is returned to the neutral position, the controller 65 stops the operation of the extension / contraction mechanism at that time. (Boom-to-boom fixing release process) The controller 65 outputs a signal for pulling out the fixing pin 16d to the fixing pin driving means 40.
Specifically, a signal is sent to the solenoid switching valve 108 of FIG. 4, the fixed pin drive cylinder 41 is driven, and the fixed pin 16d is moved to the extraction side. That is, when the fixed pin drive cylinder 41 of the fixed pin drive means 40 is extended, the fixed pin drive lever 42 swings, and the roller 44 positioned at one end of the fixed pin drive lever 42 moves inside the fixed pin 16d. It acts on the opening side 37 of the connecting member 33 located at the end. Then, the ball 35 of the ball lock mechanism 34 is pushed back by disengaging the notch 36 of the fixing pin 16d, and the tip portion 53 of the fixing pin 16d comes out of the fixing hole 51 of the fifth boom 15. As a result, the fixation of the top boom base end portion 16a and the fifth boom 15 by the boom connecting mechanism 50 of the top boom 16 is released. (Boom expansion / contraction process) By a signal from the fixing pin state detecting means 120 shown in FIG. When the release is confirmed, an extension signal is output from the controller 65 to the driving hydraulic pressure supply means 100, and the telescopic cylinder 1 is moved to the top boom 16.
The expansion operation of is started.

Specifically, based on the operation amount of the expansion / contraction operation lever 61, the controller 65 of FIG.
A signal is output to 02a, the pilot pressure is applied to the first control valve 103a to switch it, and the telescopic cylinder 1 extends to extend the top boom 16.

At this time, since the state of the telescopic boom 10 is not in the vicinity where the cylinder / boom engagement / disengagement mechanism 20 or the boom-to-boom connection mechanism 50 operates, the controller 65
Then, the process proceeds from step 4 to step 8 and the operation mode switching means 62 is set to the high speed mode. Therefore, the process proceeds from step 8 to step 11. Since the operation lever 61 is operated to the maximum, the process proceeds from step 11 to step 12.
First, the process proceeds from step 12 to step 14 to operate the first control valve 103a in step 14 until the first control valve 103a operates to the maximum, and then to proceed from step 12 to step 13 to operate the second control valve 103b. The second control valve 103b operates with the operation amount determined by the operation amount of the operation lever 61-the maximum operation amount of the first control valve 103a.

Since the telescopic cylinder 1 is extended by the two control valves including the first control valve 103a and the second control valve 103b as described above, the telescopic cylinder 1 can be operated quickly.

Next, the case where the operation mode switching means 62 is set to the low speed mode will be described. In this case, the controller 65 proceeds from step 8 to step 9. Since the operating lever 61 is operated to the maximum in step 9, the process proceeds from step 9 to step 10 to fully operate the first control valve 103a to extend the telescopic cylinder 1. That is, even if the operating lever 61 is operated to the maximum, if the operation mode switching means 62 is set to the low speed mode, the first control valve 103
The telescopic boom 1 is extended only by a. Also,
When the operation lever 61 is returned to the neutral position side and the operation amount is decreased so as to be less than the operation amount for maximally operating the first control valve 103a, the process proceeds from step 9 to step 7, and the operation amount of the operation lever 61 is set to the first value. 1 The control valve 103a is activated.

Then, the proximity determining means 65a of the controller 65, based on the signal from the cylinder length detecting means 90, holds the fixing pin 16d held by the fixing pin driving means 40.
Is determined to have approached the target fixing hole 54 of the fifth boom 15 by a predetermined distance. At this time, the process proceeds from step 4 to step 5 and the operation lever 61
If is operated to the maximum, the process proceeds from step 5 to step 6. In step 6, a signal is output from the controller 65 to the solenoid proportional valve 102a so that the first control valve 103a is operated by a predetermined operation amount (predetermined fine speed operation amount).
Then, the telescopic cylinder 1 is extended at a slow speed to the target position where the boom coupling mechanism 50 operates. In this way, when the proximity determining means 65a determines the proximity, the first control valve 10
Since only the first control valve 103a is operated with a predetermined operation amount (in this case, a slight speed operation amount), the inter-boom coupling mechanism 50 can be reliably operated.

When the operation lever 61 is operated less than the predetermined operation amount, the process proceeds from step 5 to step 7 and the operation amount of the operation lever 61 is used to control the first control valve 103.
A signal is output from the controller 65 to the solenoid proportional valve 102a so as to operate a. In this case, since the telescopic boom 1 is extended at a speed slower than the set slow speed, the boom-to-boom connection mechanism 50 can be reliably operated.

Then, the controller 65 uses the fixed pin 1
When it is determined that 6d has reached the target fixing hole position, the boom-to-boom fixing stroke described below is entered.

After the boom expanding / contracting stroke is completed, the cylinder length detecting means 90 of the expandable / contracting boom state detecting means 75 detects the expanding / contracting length of the expanding / contracting cylinder in the objective boom expanding / contracting stroke. The controller 65 reads out the specified extension / contraction length determined by the stored position of the fixing hole of the boom-to-boom coupling mechanism based on the detection value of the cylinder length detection means, and the specified extension / contraction length is expanded / contracted to the target boom. Stretch length in the process. And further controller 6
Reference numeral 5 determines the boom state after the expansion / contraction operation from the boom state before the expansion / contraction operation and the expansion / contraction length in the boom expansion / contraction stroke. (Boom-to-boom fixed stroke) The configurations of the boom / cylinder engagement / disengagement mechanism 20, the boom-to-boom connection mechanism 50, and the fixed-pin drive means 40 of the boom-to-boom connection mechanism 50 are the same before and after the boom expansion / contraction stroke. 2 is used for the explanation. Reference numeral 55 denotes a fixing boss provided on the side surface of the tip portion of the fifth boom 15, and a fixing hole 54 is provided therein. When a signal is output from the controller 65 of FIG. 4 to the solenoid valve 108 and the fixed pin drive cylinder 41 of the fixed pin drive means 40 is contracted, the tip portion 53 of the fixed pin 16d enters the fixed hole 54. The ball lock mechanism 3 of the boom-to-boom connection mechanism 50 of the top boom base end portion 16a
The fourth ball 35 enters the notch 36 of the fixing pin 16d, and the fixing pin 16d is held with the tip portion 53 of the fixing pin 16d inserted in the fixing hole 54. As a result, the top boom base end portion 16a and the fifth boom 15 are fixed. (Cylinder / boom connection release process) Further, when the extension side operation of the extension / contraction operation lever 61 is continued, the controller 65 connects the cylinder / boom engagement / disengagement mechanism 20 with the connection pin 2.
Outputs the 3 extraction signal. Specifically, a signal is sent to the solenoid switching valve 107 of FIG. 4, the connecting pin drive cylinder 21 is driven, and the connecting pin 23 is moved to the extraction side.
That is, when the connecting pin drive cylinder 21 of the cylinder / boom engaging / disengaging mechanism 20 is extended from the state shown in FIG. 2, the connecting pin 23 is pulled out from the connecting hole 16b of the top boom base end 16a. As a result, the connection between the cylinder tube rod side end 3 of the telescopic cylinder 1 and the top boom base end 16a is released. (Expansion / contraction cylinder expansion / contraction process) The connecting pin state detecting means 1
When the disconnection between the cylinder / boom connecting means 20 and the top boom base end portion 16a is confirmed by the signal from the controller 10, the controller 65 causes the driving hydraulic pressure supplying means 10 to be released.
A signal is sent to 0, and the telescopic cylinder 1 independently starts the telescopic operation without driving any boom. In this case, the telescopic cylinder 1 performs a contracting operation.

Specifically, a signal is output from the controller 65 of FIG. 4 to the electromagnetic proportional valves 101a and 101b, the first control valve 103a and the first control valve 103b are switched, and the telescopic cylinder 1 is contracted. To do. Controller 6
Reference numeral 5 is a signal based on a signal from the cylinder length detecting means 90, and causes the telescopic cylinder 1 to be contracted until the connecting pin 23 of the cylinder / boom engagement / disengagement mechanism 20 passes the position of the fifth end 15a of the fifth boom relative to the connecting hole 15b by a predetermined distance. After outputting, the output is stopped and the contraction of the telescopic cylinder 1 is stopped.

After that, the controller 65 outputs a signal to the solenoid proportional valve 101a to switch the first control valve 103a to extend the telescopic cylinder 1. Based on the signal from the cylinder length detecting means 90, the proximity determining means 65a of the controller 65 causes the connecting pin 23 of the cylinder / boom engaging / disengaging mechanism 20 to reach a predetermined distance from the connecting hole 15b of the fifth boom base end portion 15a. When the proximity discriminating means 65a of the controller 65 discriminates that the vehicle has approached, the first control valve 10 is operated by the steps 4, 5, and 6 as described above.
3a is operated with a predetermined operation amount (fine speed operation amount), and the telescopic cylinder 1 is extended at a slow speed. And the controller 65
Is the connecting pin 23 of the cylinder / boom engagement / disengagement mechanism 20.
Connection hole 15 of the Fifth boom base end 15a
When it is determined that the pressure has reached b, the process moves to the cylinder / boom coupling process described below.

The target position for shifting to the cylinder / boom coupling stroke is, together with the signal from the cylinder length detector 90,
It is determined by the signal from the boom base end position detecting means 80. Specifically, it is determined that the proximity switch 85 shown in FIG. 6 has reached the target position by detecting the detection piece 15f installed on the base end portion 15a of the fifth boom,
The process moves to the cylinder / boom coupling process described below. (Cylinder / boom connection process) A connection signal is output from the controller 65 to the cylinder / boom engagement / disengagement mechanism 20. Specifically, when a signal is output from the controller 65 to the solenoid switching valve 107 in FIG. 4 and the connecting pin drive cylinder 21 shown in FIG. 2 is contracted, the connecting pin drive lever 22 swings and the connecting pin 23 moves. It enters into the connection hole 15b of the base end portion 15a of the fifth boom. As a result, the cylinder tube side end 3 of the telescopic cylinder 1 and the fifth boom base end 15a are integrally connected.

After that, when the fifth boom 15 is extended by repeating the above-described steps to reach the final desired boom state shown in FIG. 8, the telescopic boom telescopic control device ends its operation. .

Although not described in detail in the above description of the embodiment, when operating the first control valve 103a and the second control valve 103b, when switching to a predetermined operation amount, from high speed to low speed or from low speed to high speed. When switching, it does not switch suddenly but switches gently.

In the above description of the embodiment, the embodiment in which the telescopic boom 10 is extended has been described, but it goes without saying that the same operation is performed when the telescopic boom 10 is contracted.

Further, in the above embodiment, the cylinder
Although the proximity determining means 65a is operated in the vicinity of both the boom engaging / disengaging mechanism 20 and the boom-to-boom connecting mechanism 50, it is possible to operate only one of them.

Further, in the description of the above embodiment, by setting the final boom state with the final boom state input means 63 and operating the telescopic operating lever 61, the controller 65 causes the telescopic cylinder 1 to automatically reach the final boom state. Although the connection pin drive cylinder 21 and the fixed pin drive cylinder 41 are driven, the present invention can be implemented even when the operator manually operates the telescopic cylinder 1 to extend and contract. In this case, the controller 65 may receive the signal from the telescopic boom state detecting means 75 and cause the proximity determining means 65a to operate in the same manner as described above.

In the above embodiment, the first control valve 103a and the second control valve 103b having the same characteristics are used, and the first control valve 1
03a first to the maximum and then the second control valve 103b
The control valve operating sequence means 65f is electrically controlled by the controller 65 to operate (see FIG. 10 (a)), but the first control valve 103a is operated up to a predetermined position (which can be arbitrarily set). Then, the controller 65 may be electrically controlled by the controller 65 to operate the second control valve 103b to configure the control valve operation order means 65f (see FIG. 11).

In the above embodiment, the control valves having the same characteristics are electrically delayed to open the first control valve 103a and the second control valve 103b, but the control valves are opened immediately in response to the manipulated variable signal. A control valve having a characteristic and the second control valve 103b having a characteristic which opens when an operation amount signal of a predetermined value or more is opened (control valves having different characteristics), and both control valves output the operation signal at the same time. It may be one. Furthermore,
The return springs of the respective control valves may be changed so as to operate as described above, and the return valves may be operated in the same manner.

In the above embodiment, two control valves (first control valve 103a and second control valve 103b) are used, but two or more control valves may be used.

[0058]

The telescopic boom telescopic control device according to claim 1 of the present invention is capable of shortening the total telescopic time of the telescopic boom by extending and retracting the telescopic cylinder with a plurality of control valves to accelerate the telescopic speed. Come on. Further, the controller is provided with proximity determining means for operating the cylinder / boom engagement / disengagement mechanism and the boom-to-boom coupling mechanism, and control valve output means for operating the telescopic cylinder with a predetermined operation amount by a single control valve. Therefore, when the cylinder / boom engagement / disengagement mechanism and the boom-to-boom connection mechanism are operated, the expansion / contraction speed of the expansion / contraction cylinder can be operated at a slow speed to reliably operate each mechanism.

The telescopic boom telescopic control device according to a second aspect of the present invention is the telescopic boom telescopic control device according to the first aspect, wherein the operation mode switching means for switching between the low speed mode and the high speed mode and the controller using a single control valve in the low speed mode. Since the control valve switching means for actuating and operating with the plurality of control valves in the high speed mode and the priority means for prioritizing the control valve output means over the control valve switching means are provided, the telescopic cylinder is constituted by a single control valve. The telescopic boom can be actuated at will, either actuated or actuated by multiple control valves. Also,
When the cylinder / boom engagement / disengagement mechanism and the boom coupling mechanism are operated, the expansion / contraction speed of the expansion / contraction cylinder can be slowed to reliably operate each mechanism regardless of the operation mode switching.

Further, the extension / contraction control device for the extension / contraction boom described in claim 3 has the controller according to claim 1 as follows.
Since it is provided with the comparison means for outputting the smaller output signal of the control valve output means and the operation amount signal from the operation command means to the control valve, it is determined to be in the vicinity by the proximity determination means. Even if the predetermined operation amount signal is output by the operation command means, if the operation signal less than the predetermined operation amount is output, the control valve is operated by the operation amount signal from the operation command means. It Therefore, when operating the cylinder / boom engagement / disengagement mechanism and the boom-to-boom coupling mechanism when the operation command means outputs an operation signal smaller than a predetermined operation amount, the extension / contraction speed of the extension / contraction cylinder is further reduced. It is possible to operate and reliably operate each of the above-mentioned mechanisms. Moreover, in this case, when the proximity determining means determines the proximity, the control valve is continuously operated by the operation amount signal from the operation commanding means instead of the predetermined operation amount, and the operation amount is not suddenly changed to the predetermined operation amount. Therefore, it is possible to make the operation feeling comfortable.

The telescopic boom telescopic control device according to a fourth aspect of the present invention is the telescopic boom telescopic control device according to the first aspect, wherein the plurality of control valves are composed of a first control valve and a second control valve. When the telescopic cylinder is drive-controlled by a plurality of control valves, it is provided with a control valve actuating forward means for actuating the first control valve to an arbitrary position first and then actuating the second control valve. Therefore, the control from the slow speed to the low speed, from the low speed to the high speed, or in the reverse direction can be smoothly controlled by the two control valves.

[Brief description of drawings]

FIG. 1 is a cross-sectional view along a telescopic cylinder in an explanatory view for explaining a 6-stage telescopic boom in which a telescopic boom telescopic control device using one telescopic cylinder is used.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 and is an explanatory view illustrating a cylinder / boom engagement / disengagement mechanism and a boom-to-boom coupling mechanism.

3 is an explanatory view for explaining the boom-to-boom connection mechanism in the BB arrow view of FIG. 2. FIG.

FIG. 4 is a block diagram and a hydraulic circuit diagram illustrating a telescopic boom telescopic control device of the present invention.

FIG. 5 is an explanatory diagram illustrating a display screen of an expansion / contraction related information display unit.

6 is an explanatory view showing a concrete example of a boom base end position detecting means, which is a view taken in the direction of arrows D-D in FIG. 1. FIG.

FIG. 7 is an explanatory view showing a connecting pin state detecting means taken along the line CC of FIG.

FIG. 8 is an explanatory diagram showing a state of the telescopic boom in which the top boom and the fifth boom are extended at the maximum hoisting angle of the telescopic boom.

FIG. 9 is an explanatory diagram illustrating a function of a controller with a flowchart.

FIG. 10 is an explanatory diagram for explaining the relationship between the operation amount and the flow rate of the control valve, in which (a) is a high speed and (b) is a low speed.

FIG. 11 is an explanatory diagram illustrating a relationship between a control valve flow rate and an operation amount according to another embodiment, in which (a) is a high speed and (b) is a low speed.

[Explanation of symbols]

1 is a telescopic cylinder, 2 is a cylinder tube, 3 is a cylinder tube rod side end, 4 is a rod, 5 is a rod end, 10 is a telescopic boom, 11 is a base boom, 12 is a second boom, 13 is a third boom, 14 Is a force boom, 15 is a fifth boom, 16 is a top boom, 1
6a is the base end of the top boom, 16c is a connecting boss, 16b
Is a connecting hole, 16e is a fixed pin housing member, 16d is a fixed pin, 16f is a detection piece, 20 is a cylinder / boom engaging / disengaging mechanism, 21 is a connecting pin drive cylinder, 22 is a connecting pin drive lever, 23 is a connecting pin, 25 Is a trunnion member, 33
Is a connecting member, 34 is a ball lock mechanism, 35 is a ball,
36 is a notch, 40 is a fixed pin drive means, 41 is a fixed pin drive cylinder, 42 is a fixed pin drive lever, 50 is a boom connecting mechanism, 51 and 54 are fixed holes, 52 and 55 are fixed bosses, 53 is a fixed pin. End portion, 60 extension / contraction mechanism operation means, 61 extension / contraction operation lever, 62 operation mode switching means, 63 final boom state input means, 65 controller, 65a proximity determination means, 65b control valve output means,
65c is control valve switching means, 65d is prioritizing means, 65e is comparing means, 65f is control valve operating order means, 70 is expansion / contraction related information display means, 75 is expansion / contraction boom state detecting means, 80 is boom base end position detecting means, 82-86 are proximity switches,
90 is a cylinder length detecting means, 91 is a code, 95 is a length detector, 100 is a drive oil pressure supplying means, 101a and 10a.
2a is a solenoid proportional valve, 101b and 102b are solenoid proportional valves,
103a is a first control valve (first pilot type switching valve), 1
03b is the second control valve (second pilot type switching valve), 10
4a and 104b are counter balance valves, and 105a is the first
Hydraulic pump 105b is a second hydraulic pump 106a and 1
06b is a relief valve, 109a and 109b are flow control valves, 107 and 108 are solenoid switching valves, 110 is a connecting pin state detecting means, 111 is a detecting piece, 112 and 113 are proximity switches, 120 is a fixed pin state detecting means, 121
Is the detection piece

Claims (4)

[Claims] 1. A telescopic cylinder configured to alternately telescope each boom stage of a telescopic boom composed of a multi-stage boom which is telescopically inserted, and a hydraulic pressure from a hydraulic source is supplied to the telescopic cylinder to extend and contract. A control valve that controls and drives the cylinder, a cylinder / boom engagement / disengagement mechanism that engages / disengages the telescopic boom and each boom stage, a boom-to-boom coupling mechanism that disconnects and uncouples adjacent boom stages, and a telescopic boom The telescopic boom state detection means for detecting the boom state, the operation command means for instructing the operation direction and the operation amount when the telescopic boom is extended and retracted, and the telescopic boom receiving the signals from the operation instruction means and the telescopic boom state detection means. The control valve, the cylinder / boom engagement / disengagement mechanism, and And a controller for appropriately outputting a signal for operating the boom-to-boom connection mechanism, wherein the telescopic boom telescopic control device is provided with a plurality of the control valves, and hydraulic pressure can be supplied to and discharged from the plurality of control valves in the telescopic cylinder. A controller for receiving a detection signal from the telescopic boom state detecting means and for determining whether the telescopic boom is in the vicinity where the cylinder / boom engagement / disengagement mechanism or the boom-to-boom connection mechanism operates. An expansion / contraction control device for an expansion / contraction boom, comprising: a control valve output means for outputting a predetermined operation amount to a single control valve when the proximity determination means determines that the proximity is close. 2. An operation mode switching means for switching an operation mode between a high speed mode for operating the telescopic cylinder at a high speed and a low speed mode for operating the low speed cylinder, and the controller comprises:
Control valve switching for supplying hydraulic pressure from a plurality of control valves to the telescopic cylinder when the operating mode switching means is switched to the high speed mode, and hydraulic pressure supplied from a single control valve to the telescopic cylinder when operating mode switching means is switched to the low speed mode 2. The telescopic boom extension / contraction control device according to claim 1, further comprising output means and priority means for outputting the control valve output means in preference to the control valve switching output means. 3. The controller includes a comparison means for outputting to the control valve the output signal from the control valve output means and the smaller output signal to the control valve based on the operation amount signal from the operation command means. The telescopic boom telescopic control device according to claim 1 or 2, further comprising: 4. A plurality of control valves comprising a first control valve and a second control valve, wherein the controller controls the first control when the telescopic cylinder is driven by the plurality of control valves. The telescopic boom telescopic control device according to any one of claims 1 to 3, further comprising a control valve operating sequence means for operating the valve to an arbitrary position first and then operating the second control valve.