JP5684996B2 - boom - Google Patents

Description

The present invention relates to the boom.

  2. Description of the Related Art Conventionally, as shown in Patent Document 1, for example, a boom expansion / contraction mechanism is known that expands and contracts by a single expansion cylinder while locking each stage of a boom member with a pin.

  In this boom extension / contraction mechanism, the extension cylinder has an extra extension stroke with respect to the extension / contraction stroke of the boom member at each stage due to the structure using one extension cylinder. This is because when the boom stroke position differs depending on the boom stage (the closer to the rear boom, the closer to the rear end of the boom), the extension stroke of the telescopic cylinder when the inner boom is fully extended causes the outer boom to be fully extended. This is because the outer boom cannot be fully extended unless it is longer than the extension stroke of the telescopic cylinder.

  The boom having such a telescopic mechanism is controlled by the control device so that each boom stage strokes a predetermined stroke position.

Japanese Patent No. 3212467

  However, if the control device malfunctions due to unforeseen circumstances, the booms at each stage may overstroke beyond a predetermined stroke position.

  Then, due to the overstroke, the wrap length of the inner boom member and the outer boom member is shortened, which may cause excessive stress on the boom member.

Then, this invention aims at providing the boom which prevents an overstroke.

In order to achieve the above object, the boom of the present invention includes a plurality of boom members configured in a nested manner, a telescopic cylinder that feeds the boom member while being fixed by a cylinder / boom coupling means, and a fixed position that is set. A boom comprising: a boom fixing means for fixing an inner boom member and an outer boom member; and a controller for controlling driving of the telescopic cylinder and the boom fixing means , wherein the inner boom member exceeds the fixing position. And a boom movement excess prevention means for preventing the movement of the inner boom member by stopping the operation of the telescopic cylinder without using the controller .

As described above, the boom of the present invention includes a multi-stage boom member configured in a nested manner, an extension cylinder that feeds the boom member while fixing the boom member with the cylinder / boom coupling means, and an inner boom member at the set fixing position. A boom comprising a boom fixing means for fixing an outer boom member, and a controller for controlling driving of the telescopic cylinder and the boom fixing means. When the inner boom member exceeds a fixing position, the boom is extended and retracted without using the controller. Boom movement excess prevention means for stopping the cylinder and preventing movement of the inner boom member is provided.

  Therefore, by preventing the overstroke of the telescopic cylinder by the boom movement excess preventing means, the boom can be a safe boom without the possibility of excessive stress acting on the boom member.

It is a block diagram explaining the structure of the control system of the boom of Example 1. FIG. It is a side view explaining the whole structure of an all terrain crane. It is sectional drawing explaining the structure of a boom. It is explanatory drawing explaining the relationship between a boom and the length of an expansion-contraction cylinder. It is sectional drawing explaining the structure of a detection apparatus. (A) is a general view and (b) is an enlarged view. It is a hydraulic circuit diagram explaining the structure of a switching circuit. It is sectional drawing explaining the structure of the detection apparatus of Example 2. FIG. It is sectional drawing explaining the structure of the detection apparatus of another Example. (A) is a general view and (b) is an enlarged view.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the structure of the mechanical system of the all terrain crane 1 as a crane provided with the boom 2 of a present Example is demonstrated using FIG. In the following first and second embodiments, the all terrain crane 1 will be described as an example. However, the present invention is not limited to this, and the present invention is widely applied to a crane including a multi-stage nested boom such as a rough terrain crane. Applicable.

(Configuration of crane)
As shown in the side view of FIG. 2, the all terrain crane 1 of this embodiment includes a carrier 10 that is a vehicle main body having a traveling function, outriggers 11 provided at four corners of the carrier 10, and a carrier. And a boom 2 attached to a bracket 13 erected on the turntable 12.

  The boom 2 is configured in a five-stage nesting manner by five boom members including a base boom 21, a second boom 22, a third boom 23, a force boom 24, and a top boom 25. A boom telescopic mechanism 3 is formed inside the boom 2 to extend and contract each boom member by a single telescopic cylinder 30.

  Further, the base boom 21 is swingably attached to a support shaft that is horizontally attached to the bracket 13 so that the base boom 21 can be raised and lowered up and down around the support shaft.

  Further, a hoisting cylinder 15 is stretched between the bracket 13 and the base boom 21, and the entire boom 2 can be hoisted by extending and retracting the hoisting cylinder 15.

  Further, a sheave (not shown) is disposed on the most advanced boom head 26 of the top boom 25, and a rope 16 is wound around the sheave and a hook 17 is suspended.

(Configuration of boom telescopic mechanism)
Next, the boom expansion / contraction mechanism 3 formed inside the boom 2 will be described by taking a base boom 21 and a second boom 22 as boom members as examples. The configuration of the boom telescopic mechanism 3 is substantially the same for the second boom 22 and the third boom 23, the third boom 23 and the force boom 24, and the force boom 24 and the top boom 25.

  As shown in the sectional view of FIG. 3, the boom telescopic mechanism 3 of the present embodiment includes a cylinder / boom coupling means 31 for coupling the telescopic cylinder 30 and the base boom 21, and a boom fixing for fixing the second boom 22 and the base boom 21. Means 32.

  The cylinder / boom connecting means 31 includes a connecting pin driving cylinder 31a, a connecting pin driving arm 31b and a connecting pin 31c arranged on the cylinder rod 30b side (see FIG. 4) of the cylinder tube 30a of the telescopic cylinder 30, and the second boom 22. And a connecting boss 22d disposed at the base end portion. The telescopic cylinder 30 and the second boom 22 are connected by inserting the connecting pin 31c into the connecting boss 22d.

  In addition, the boom fixing means 32 includes a storage portion 22e provided at the base end portion of the second boom 22, a boom fixing pin 22a disposed in the storage portion 22e so as to freely advance and retract, and a base end fixing provided at the base end portion of the base boom 21. A boss 21b, a fixed pin drive cylinder (not shown), a fixed pin drive arm (not shown), and a roller 32c disposed on the cylinder rod 30b side of the cylinder tube 30a of the telescopic cylinder 30 are provided. The second boom 22 and the base boom 21 are connected by inserting the boom fixing pin 22a into the base end fixing boss 21b.

  For example, in the fully contracted state, as shown in the explanatory view of FIG. 4, the boom fixing pin 22 a of the inner second boom 22 is hooked on the base end fixing boss 21 b of the outer base boom 21, and the second boom 22. Is fixed to the base boom 21 in a contracted state.

  In the fully extended state, the boom fixing pin 22a of the inner second boom 22 is inserted into the distal end fixing boss 21c of the outer base boom 21, and is fixed to the base boom 21 with the second boom 22 extended.

Then, in the boom 2 of this embodiment, the stroke L _t when the boom fixing pin 25 a of the top boom 25 is inserted into the tip fixing boss 24 c of the force boom 24 is the longest stroke position of the telescopic cylinder 30.

On the other hand, the stroke L ₂ at the time of inserting the boom fixing pin 22a of the second boom 22 to the tip fixed boss 21c of the base boom 21 becomes the shortest stroke position of the telescopic cylinder. At this shortest stroke position, a margin ΔL of the length of (L _t −L ₂ ) occurs.

  Even if the stroke exceeds the shortest stroke state, the second boom 22 will not fall out because there is a certain amount of lap at the distal end of the base boom 21 and the proximal end of the second boom 22. If the length of the wrap portion is shortened, an excessive stress may act on the second boom 22.

(Configuration of boom movement excess prevention means)
And in the boom expansion-contraction mechanism 3 of a present Example, when inserting the boom fixing pin 22a of the second boom 22 with the largest margin (DELTA) L in the front-end | tip fixed boss | hub 21c of the base boom 21, as shown in FIG. The boom movement excess preventing means 4 for preventing the second boom 22 from overstroke is installed.

  The boom movement excess prevention means 4 includes a detection device 5 (see FIG. 5) that detects that the inner boom member is located in the vicinity of the fixed position, and the movement of the inner boom member in response to a signal from the detection device 5. And a switching circuit 6 (see FIG. 6) as a regulating device for regulating.

  As shown in the cross-sectional view of FIG. 5B, the detection device 5 includes a detection target 51 arranged outside the lower surface of the second boom 22, and a detector 52 arranged protruding from the inside of the lower surface of the base boom 21. It is equipped with.

  Since the detected body 51 is formed as a cam protruding in a trapezoidal cross section from the outside of the lower surface of the second boom 22, the detected body 51 comes into contact with the spherical tip of the detector 52 when it moves to the vicinity of a preset fixed position.

  Furthermore, since the detector 52 is a push-type mechanical switch, if the second tip 22 is detected in the vicinity of the fixed position when the spherical tip is pushed in contact with the detected object 51, the electromagnetic wave is detected. A detection signal is transmitted to the proportional valves 101 and 102 (see FIG. 6).

  Here, the position of the second boom 22 when the boom fixing pin 22a of the second boom 22 faces the tip fixing boss 21c of the base boom 21 is set as the fixing position. Furthermore, the vicinity of the fixed position refers to a range including the fixed position and a position beyond the fixed position by a predetermined minute distance (for example, 5 cm).

  Further, as shown in the hydraulic circuit diagram of FIG. 6, the switching circuit 6 serving as the regulating device includes a counter balance valve that applies back pressure to the expansion cylinder 30 and the cap side as expansion cylinder driving means 33 that drives the expansion cylinder 30. 104, a pilot-type switching valve 103 that drives the telescopic cylinder 30, electromagnetic proportional valves 101 and 102 that send pilot pressure to the pilot-type switching valve 103, and a flow rate adjusting valve 109 that adjusts the flow rate.

  Furthermore, the switching circuit 6 includes a connecting pin drive cylinder 31 a, a hose reel 105, a pilot check valve 106, and a solenoid switching valve 107 as a hydraulic circuit for driving the cylinder / boom connecting means 31.

  Similarly, the switching circuit 6 includes a fixed pin drive cylinder 32a, a hose reel 105, a pilot check valve 106, and a solenoid switching valve 108 as a hydraulic circuit for driving the boom fixing means 32.

  The switching circuit 6 includes a controller 60 that controls the electromagnetic proportional valves 101 and 102 and the solenoid switching valves 107 and 108. The controller 60 is a general-purpose microcomputer that includes a CPU, memory, HDD, SSD, and the like.

  And in the switching circuit 6 as a control apparatus of a present Example, the detector 52 installed in the second boom 22 and the electromagnetic proportional valves 101 and 102 are directly connected.

  For this reason, when the detector 52 detects that the fixed position is exceeded, the electromagnetic proportional valves 101 and 102 directly move the pilot-type switching valve 103 to the neutral position without using the controller 60. The operation of the telescopic cylinder 30 is stopped.

(Control system configuration)
Next, the configuration of the control system of the boom 2 of this embodiment will be described with reference to the block diagram of FIG.

  The control system S of the present embodiment is connected as an input system to the telescopic operation lever 71 through which an operator inputs expansion or contraction of the boom 2, the manual changeover switch 72 to release the control device, and the connection or disconnection of the connection pin 31c. Connecting pin state detecting means 73 for detecting, fixing pin state detecting means 74 for detecting whether the boom fixing pins 22a to 25a are fixed or not, boom length detecting means 75 for detecting the length of the boom 2, and telescopic cylinder Cylinder length detecting means 76 for detecting 30 lengths.

  In addition, the control system S includes a cylinder / boom coupling means 31, a boom fixing means 32, a telescopic cylinder driving means 33, and a display monitor 81 that displays information related to safety as an output system.

  In the control system S of the present embodiment, the detecting device 5 for detecting that the boom member is in the vicinity of the fixed position is directly connected to the telescopic cylinder driving means 33 without using the controller 60.

(Function)
Next, the operation of the boom telescopic mechanism 3 and the boom movement excess preventing means 4 according to the present embodiment will be described with reference to FIGS. Note that the third boom 23 is sequentially extended from the top boom 25 before the extension of the second boom 22 described below.

  When extending the second boom 22, the controller 60 first drives the connecting pin drive cylinder 31a by the solenoid switching valve 107 to insert the connecting pin 31c into the connecting boss 22d (see FIG. 3). Subsequently, the controller 60 pulls out the boom fixing pin 22a of the second boom 22 from the base end fixing boss 21b of the base boom 21 to release the fixation of the second boom 22 and the base boom 21.

  That is, the controller 60 drives the fixed pin drive cylinder 32a by the solenoid switching valve 108, moves the boom fixed pin 22a inward, and pulls it out from the proximal end fixed boss 21b.

  Next, after the release, the telescopic cylinder 30 is extended and the second boom 22 is extended, and then the boom fixing pin 22a is inserted into the distal end fixing boss 21c of the base boom 21 to fix the second boom 22 and the base boom 21.

  That is, the controller 60 drives the connecting pin drive cylinder 31a by the solenoid switching valve 107 and inserts the connecting pin 31c into the connecting boss 22d (see FIG. 3). Subsequently, the controller 60 extends the telescopic cylinder 30 with the second boom 22 held by the electromagnetic proportional valves 101 and 102. Further, when the controller 60 moves to the fixed position set by the second boom 22, the controller 60 drives the fixed pin driving cylinder 32a by the solenoid switching valve 108, and inserts the boom fixing pin 22a into the tip fixing boss 21c.

  At this time, the controller 60 determines whether or not the second boom 22 is in a fixed position with respect to the base boom 21 based on the input values from the boom length detection means 75 and the cylinder length detection means 76 and executes control. Yes.

  Even if the control by the control device becomes impossible for some reason, the boom 2 according to the present embodiment includes the boom movement excess prevention means 4, so that the movement of the boom 2 is stopped when the boom 2 is exceeded. .

  That is, the position where the second boom 22 exceeds the fixed position in each state such as when the control device is released and the control operation is manually operated, when there is a radio wave interference or lightning strike, or when a detector failure occurs. The hypotenuse of the detected object 51 pushes the spherical tip of the detector 52.

  Then, the detector 52 that has detected that the second boom 22 is positioned in the vicinity of the fixed position transmits a signal to the electromagnetic proportional valves 101 and 102 of the switching circuit 6 so that the pilot-type switching valve 103 is automatically set to the neutral position. Therefore, the movement of the telescopic cylinder 30 is stopped.

(effect)
Next, the effects of the boom 2 of this embodiment will be listed and described.

  (1) As described above, the boom 2 of the present embodiment is configured such that the base boom 21 and the second boom 22 as a plurality of boom members configured in a nested manner and the boom member are fixed by the cylinder / boom coupling means 31. In the boom 2 including the telescoping cylinder 30 to be sent out, and the boom fixing means 32 that fixes the second boom 22 as the inner boom member and the base boom 21 as the outer boom member at the set fixing position, the second boom 22 is Boom movement excess prevention means 4 for preventing movement beyond the fixed position is provided.

  Therefore, by preventing the overstroke of the telescopic cylinder 30 by the boom movement excess prevention means 4, the wrap length between the boom members is not shortened, so that a safe boom without excessive stress acting on the boom members. 2.

  (2) Further, the boom movement excess preventing means 4 detects the second boom 22 as the inner boom member located near the fixed position, and receives the signal from the detection device 5 to receive the second boom 22. And a switching circuit 6 as a restricting device for restricting movement of.

  For this reason, when the second boom 22 is located in the vicinity of the fixed position, this is detected quickly and reliably by the dedicated detection device 5 and the movement of the second boom 22 is automatically stopped without using the control device. it can.

  (3) Furthermore, the detection device 5 includes the detected body 51 disposed on the second boom 22 and the mechanical detector 52 disposed on the base boom 21, so that the second boom 22 is in the vicinity of the fixed position. Can be detected easily and reliably.

  In addition, if the detector 52 is disposed on the base boom 21 that is not slid, it is not necessary to wind up or send out an electric cord or a communication cord connected to the detector 52. Easy to supply.

  (4) Further, as a regulating device, by configuring the switching circuit 6 that automatically switches the pilot-type switching valve 103 as the expansion / contraction driving valve that drives the expansion / contraction cylinder 30 by the electric signal from the detection device 5 to the neutral position, Even if the control device does not operate for some reason, the movement of the boom member can be restricted using the existing hydraulic system.

  That is, in the control system S of the present embodiment, the boom movement excess preventing means 4 is configured by adding an independent signal system different from the signal system of the control device, so that the boom member can be used even when the control device does not operate normally. Can be controlled. In addition, since the existing hydraulic system is used as it is, the configuration of the hydraulic system can be simplified as a whole.

  (5) And since the all terrain crane 1 as a crane of a present Example is provided with the boom 2 in any one of above-mentioned, since an overstroke of a boom member can be prevented, an excessive stress acts on a boom member. It becomes a safe all-terrain crane 1 without any problems.

  Hereinafter, a detection device 5A different from the above-described embodiment will be described with reference to FIG. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  First, the configuration will be described. The boom movement excess prevention means 4 provided in the boom 2 of the present embodiment includes a detection device 5A (see FIG. 7) for detecting that the inner boom member is located in the vicinity of the fixed position, and a detection device. A switching circuit 6 (see FIG. 6) as a regulating device that receives a signal from 5A and regulates the movement of the inner boom member.

  As shown in the cross-sectional view of FIG. 7, the detection device 5 </ b> A includes a detection object 53 disposed near the tip of the base boom 21 and a detector disposed near the end of the cylinder tube 30 a of the telescopic cylinder 30 on the cylinder rod 30 b side. 54.

  Since the detected object 53 is formed as an RF tag (IC tag), it is electromagnetically detected by the detector 54 that it has moved to the vicinity of a preset fixed position.

  Furthermore, the detector 54 is formed as an electromagnetic induction sensor. When the detector 54 detects that the second boom 22 is in the vicinity of the fixed position by detecting the electromagnetic wave of the detected object, the electromagnetic proportional valves 101 and 102 (FIG. 6). Send the detection signal.

  In addition, the specific configuration of the detection target and the detector is not limited to the above combination, and may include a reflection plate as the detection target and an optical sensor as the detection target. You may provide a magnetic sensor as a detector while providing a magnetic body.

  Next, the effect will be described.

  (1) As described above, in the boom 2 of the present embodiment, the detection device 5 </ b> A includes the detected body 53 disposed on the outer boom member and the detector 54 disposed on the cylinder tube 30 a of the telescopic cylinder 30. Thus, the overstroke of all the boom members can be detected by one detector 54.

  That is, since the detector 54 is installed in the telescopic cylinder 30, not only the base boom 21 and the second boom 22 but also the second boom 22 and the third boom 23, the third boom 23 and the force boom 24, and the force boom 24 and the top boom 25. Can be installed easily. Therefore, the overstroke of all the boom members can be detected.

  In addition, if the detector 54 is installed in the telescopic cylinder 30, the distance for winding and sending out the electric cord and the communication cord is shortened, so that these reels can be simplified.

  Other configurations and operational effects are substantially the same as those in the above-described embodiment, and thus the description thereof is omitted.

  The embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to the present invention. included.

  For example, in the above-described embodiment, the boom movement excess preventing means 4 including the detection device 5 and the switching circuit 6 has been described. However, the present invention is not limited to this, and a pair of opposing protruding pieces 55 as shown in FIG. , 56 may be provided with a mechanical (physical) boom movement excess prevention means 4A. That is, the first protruding piece 55 installed on the base boom 21 and the second protruding piece 56 installed on the second boom 22 may be forcibly prevented from moving beyond the fixed position. .

  Although not particularly described in the above embodiment, when the boom movement excess preventing means 4 is activated because the fixed position has been exceeded, a warning message is displayed on the display monitor 81, or a warning buzzer or the like is notified. You may do it.

  Further, in the above embodiment, the case where the detectors 52 and 54 are connected only to the electromagnetic proportional valves 101 and 102 has been described. However, the present invention is not limited to this, and the detectors 52 and 54 are connected to the controller 60. Also good. Even in this configuration, when an abnormality occurs in the boom length detecting means 75 or the cylinder length detecting means 76, an overstroke can be prevented.

1 All terrain crane (crane)
2 Boom 21 Base boom (boom member)
22 Second boom (boom member)
23 Third boom (boom member)
24 Force boom (boom member)
25 Top boom (boom member)
3 Boom telescopic mechanism 30 Telescopic cylinder 30a Cylinder tube 30b Cylinder rod 31 Cylinder / boom coupling means 32 Boom fixing means 4, 4A Boom movement excess preventing means 5, 5A Detectors 51, 53 Detected objects 52, 54 Detectors 55, 56 Projection piece 6 Switching circuit (Regulator)
60 controller

Claims (5)

A boom member configured to fix the inner boom member and the outer boom member at a set fixing position, a plurality of boom members configured in a nested manner, an extendable cylinder that feeds the boom member while being fixed by a cylinder / boom coupling means In a boom , comprising: a fixing means; and a controller that controls driving of the telescopic cylinder and the boom fixing means .
When the inner boom member exceeds the fixed position, there is provided a boom movement excess preventing means for stopping the movement of the inner boom member by stopping the driving of the telescopic cylinder without passing through the controller. Boom to do.   The boom movement excess prevention means includes a detection device that detects that the inner boom member is located in the vicinity of the fixed position, and a restriction device that receives a signal from the detection device and restricts movement of the inner boom member. And the boom according to claim 1.   The boom according to claim 2, wherein the detection device includes a detected object disposed on a second boom and a detector disposed on a base boom.   The boom according to claim 2, wherein the detection device includes a detection object disposed on the outer boom member and a detector disposed on a cylinder tube of the telescopic cylinder.   5. The switching device according to claim 2, further comprising a switching circuit that automatically switches a telescopic drive valve that drives the telescopic cylinder to a neutral position by an electric signal from the detection device. The boom according to one item.