Boom control device for construction machinery

Abstract

To provide a boom control device for a construction machine that properly and safely controls operations of a multistage boom including extending and retracting of the multistage boom, in correspondence with whether or not a front portion separable from a rear portion is attached to the rear portion.SOLUTION: A multistage boom is extendable and retractable, and in a multi-stage boom, a front portion is separably attached to a rear portion. A cord of a boom control device extends from the rear portion, and an extended end of the cord can be connected to the front portion. Based on a fact that the extended end of the cord is connected to the front portion, a controller of the boom control device determines that the front portion is attached to the rear portion; and based at least on the fact that the extended end of the cord is not connected to the front portion, it determines that the front portion is separated from the rear portion. Based on a determination result of whether or not the front portion is attached to the rear portion, the controller controls an operation of the multistage boom.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a boom control device that controls the operation of a multi-stage boom that is extendable and contractable in a longitudinal direction in a construction machine. [Background technology]

[0002] Patent Document 1 discloses a crane as a construction machine equipped with a multi-stage boom that can be extended and retracted in the longitudinal direction. In this crane, the multi-stage boom includes a rear portion attached to an upper rotating body and a front portion detachably attached to the rear portion. In a crane in which the front portion of the multi-stage boom can be separated from the rear portion, the number of stages of the multi-stage boom differs between a state in which the front portion is attached to the rear portion and a state in which the front portion is separated from the rear portion. In a crane in which the front portion of the multi-stage boom can be separated from the rear portion, the front portion is transported to a work site or the like in a state in which it is separated from the rear portion. Then, at the work site, work or the like is performed using a multi-stage boom in which the front portion is attached to the rear portion and the front portion is attached to the rear portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-38072 Summary of the Invention [Problem to be solved by the invention]

[0004] In a construction machine in which the front part of the multi-stage boom can be separated from the rear part as in Patent Document 1, the number of stages of the multi-stage boom differs depending on whether the front part is attached to the rear part, and therefore the weight of the multi-stage boom and the length in the longitudinal direction of the multi-stage boom differ depending on whether the front part is attached to the rear part. For this reason, it is required to appropriately control the extension and retraction of the boom telescopic cylinder that extends and retracts the multi-stage boom depending on whether the front part is attached to the rear part, and to safely and appropriately control the extension and retraction of the multi-stage boom. It is also required to appropriately calculate the real-time working radius of the multi-stage boom, the load (actual load) applied to the multi-stage boom in real time, and the limit value (upper limit value) of the load applied to the multi-stage boom depending on whether the front part is attached to the rear part, and to safely and appropriately control the operation of the multi-stage boom based on the calculation results.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a boom control device for a construction machine that appropriately and safely controls the operation of a multi-stage boom, including the extension and contraction of the multi-stage boom, depending on whether or not a front part that is separable from a rear part is attached to the rear part. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one aspect of the present invention is a boom control device that controls the operation of a multi-stage boom that is extendable and contractable in a longitudinal direction and has a front portion detachably attached to a rear portion, the boom control device comprising: a cord extending from the rear portion and having an extended end connectable to the front portion; and a controller that determines that the front portion is attached to the rear portion based on the extended end of the cord being connected to the front portion, and determines that the front portion is separated from the rear portion based at least on the extended end of the cord not being connected to the front portion, and that controls the operation of the multi-stage boom, including extension and contraction of the multi-stage boom, based on the result of the determination of whether the front portion is attached to the rear portion. Effect of the Invention

[0007] According to the present invention, it is possible to provide a boom control device for a construction machine that appropriately and safely controls the operation of a multi-stage boom, including the extension and contraction of the multi-stage boom, depending on whether or not a front portion that is separable from a rear portion is attached to the rear portion. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a multi-stage boom according to a first embodiment, in which (a) is a state in which a front portion (first front portion) is attached to a rear portion, (b) is a state in which a front portion (second front portion) is attached to a rear portion, and (c) is a state in which both front portions are separated from the rear portion. [Diagram 2]FIG. 2 is a schematic diagram showing, in the multi-stage boom according to the first embodiment, (a) a state in which the front section (first front section) is attached to the rear section and each of the boom members (telescopic boom members) is in its most contracted state, (b) a state in which the fourth stage boom member is extended to its most extended state from (a), (c) a state in which the cylinder tube of the telescopic cylinder is connected to the third stage boom member from (b), (d) a state in which the third stage boom member is extended to a predetermined contracted state from (c), (e) a state in which the fourth stage boom member is released from the third stage boom member and the front section (first front section) is lifted up from (d), (f) a state in which the third stage boom member is contracted and the front section (first front section) is separated from the rear section from (e), and (g) a state in which the third stage boom member is contracted to its most contracted state from (f). [Diagram 3] FIG. 3 is a schematic diagram showing a system provided with a boom control device that controls the operation of a multi-stage boom in the first embodiment. [Figure 4] FIG. 4 is a schematic diagram illustrating an example of a determination by the controller regarding the connection of the connector of the cord in the first embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing another example of the determination by the controller regarding the connection of the connector of the cord in the first embodiment, different from that shown in FIG. [Figure 6] FIG. 6 is a flowchart that illustrates an example of a process for determining an attachment state between each of the front portions and the rear portion by the controller in the first embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a system in which a boom control device that controls the operation of a multi-stage boom is provided in one modified example. [Figure 8] FIG. 8 is a schematic diagram showing an example of a determination by a controller regarding the connection of the extended ends of the cord in the modified example of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

[0010] (First embodiment) First, a first embodiment, which is one of the embodiments, will be described. Fig. 1(a) to (c) show the configuration of a multi-stage boom 1 of the first embodiment. As shown in Fig. 1(a) to (c), the multi-stage boom 1 is extended along the longitudinal direction. Here, in the multi-stage boom 1, one side in the longitudinal direction is the rear side (arrow C1 side), and the opposite side to the rear side is the front side (arrow C2 side). In a crane provided with the multi-stage boom 1 as shown in Fig. 1, a rotating body (not shown) is provided on a traveling vehicle body (not shown), and the rear end of the multi-stage boom 1 is attached to the rotating body. The multi-stage boom 1 can be raised and lowered relative to the rotating body, and can be rotated together with the rotating body relative to the traveling vehicle body. In addition, an attachment (not shown) such as a jib can be attached to the front end of the multi-stage boom 1.

[0011] In this embodiment, the multi-stage boom 1 includes a rear portion 2 and two types of front portions 3A and 3B. Each of the front portions 3A and 3B is separably attached to the rear portion 2. The front portions 3A and 3B are different in type from each other, and one of the front portions 3A and 3B can be selectively attached to the rear portion 2. Therefore, one of the multiple types of front portions 3A and 3B that are different from each other can be selectively attached to the rear portion 2. Due to the above-mentioned configuration, in the multi-stage boom 1, the attachment state (connection state) between each of the front portions 3A and 3B and the rear portion 2 changes among three states: a state in which the front portion (first front portion) 3A is attached to the rear portion 2 shown in FIG. 1(a), a state in which the front portion (second front portion) 3B is attached to the rear portion 2 shown in FIG. 1(b), and a state in which both of the front portions 3A and 3B are separated from the rear portion 2 shown in FIG. 1(c).

[0012] In the multi-stage boom 1 of this embodiment, the rear section 2 includes a plurality of (three in this embodiment) boom members B1 to B3. Here, i in boom member Bi (i=1, 2, 3) indicates the stage number in the multi-stage boom 1. Each of the boom members Bi extends along the longitudinal direction of the multi-stage boom 1. In the multi-stage boom 1, the rear end of the boom member B1 of the rear section 2 is attached to a rotating body. In the multi-stage boom 1, the boom member B1 is the base boom member of the rearmost stage, and the boom member B1 of the rear section 2 is the first stage (first stage). In the multi-stage boom 1, the boom members B2 and B3 of the rear section 2 are the second and third stages, respectively. In the rear section 2, each of the boom members B2 and B3 is a telescopic boom that can be extended and contracted in the longitudinal direction of the multi-stage boom 1 relative to the boom member B1, which is the base boom member. When either of the boom members B2, B3 extends or contracts in the longitudinal direction, the dimension of the rear portion 2 of the multi-stage boom 1 along the longitudinal direction changes.

[0013] Among the boom members Bi in the rear section 2, the first boom member B1 is disposed on the outermost side, and the boom member B3 is disposed on the innermost side. Among the boom members Bi in the rear section, the higher the stage number, the more inwardly they are disposed. In the multi-stage boom 1, the rear end is formed by the first boom member (base boom member) B1. In the rear section 2, the front end is formed by the boom member B3. Among the boom members Bi in the rear section 2, the higher the stage number, the more forward the front end is located. Due to the above-mentioned configuration, in the rear section 2, the boom member B1 is one stage rearward relative to the boom member B2, and the boom member B3 is one stage forward relative to the boom member B2. In this embodiment, the boom member B3 is the boom member Bα in the most forward stage in the rear section 2. In a state in which both of the front sections 3A, 3B are separated from the rear section 2, boom member B3 becomes the foremost section (final section) in the multi-stage boom 1, and boom member B3 forms the front end of the multi-stage boom 1. Therefore, in a state in which both of the front sections 3A, 3B are separated from the rear section 2, the number of sections of the multi-stage boom 1 is three.

[0014] Moreover, in the multi-stage boom 1 of this embodiment, the front portion (first front portion) 3A includes a plurality of boom members Ba4 to Ba6 (three in this embodiment). Here, j in the boom members Baj (j=4, 5, 6) indicates the stage number in the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2. In a state in which the front portion 3A is attached to the rear portion 2, each of the boom members Baj extends along the longitudinal direction of the multi-stage boom 1. The front portion 3A is attached to the rear portion 2 by connecting the rear end portion of the boom member Ba4 to the boom member B3 of the rear portion 2. In the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, the boom members Ba4 to Ba6 are the fourth, fifth and sixth stages, respectively. Furthermore, in the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, each of the boom members Baj becomes a telescopic boom that can be extended and retracted in the longitudinal direction of the multi-stage boom 1 relative to the boom member B1, which is the base boom member. Therefore, in the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, the dimension of the multi-stage boom 1 along the longitudinal direction changes when any of the boom members B2, B3, Baj extends or contracts in the longitudinal direction. Furthermore, in the front portion 3A, a boom head 5A is provided at the front end of the boom member Ba6.

[0015] In the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, among the boom members Bi, Baj, the first boom member B1 is disposed on the outermost side, and the boom member Ba6 is disposed on the innermost side. Then, in the state in which the front portion 3A is attached to the rear portion 2, among the boom members Bi, Baj, the larger the stage number, the more inwardly the boom member is disposed. Also, in the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, the front end is formed by the boom head 5A of the boom member Ba6. Then, in the state in which the front portion 3A is attached to the rear portion 2, among the boom members Bi, Baj, the larger the stage number, the more forward the front end is located. Due to the above-mentioned configuration, in the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, the boom member B3 is one stage rearward relative to the boom member Ba4, and the boom member Ba5 is one stage forward relative to the boom member Ba4. Furthermore, with the front section 3A attached to the rear section 2, the boom member Ba6 becomes one stage forward of the boom member Ba5, and becomes the boom member Baγ which is the frontmost stage (final stage) of the multi-stage boom 1 (front section 3A). Therefore, with the front section 3A attached to the rear section 2, the multi-stage boom 1 has six stages. Furthermore, among the boom members Baj of the front section 3A attached to the rear section 2, the boom member Ba4 becomes the boom member Baβ which is the rearmost stage.

[0016] In the multi-stage boom 1 of this embodiment, the front portion (second front portion) 3B includes one or more boom members Bb4 (one in this embodiment). Here, k in the boom member Bbk (k=4) indicates the stage number in the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2. In this embodiment, the number of boom members Bbk provided in the front portion 3B is different from the number of boom members Baj provided in the front portion 3A. In a state in which the front portion 3B is attached to the rear portion 2, the boom member Bb4 extends along the longitudinal direction of the multi-stage boom 1. The front portion 3B is attached to the rear portion 2 by connecting the rear end of the boom member Bb4 to the boom member B3 of the rear portion 2. In the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, the boom member Bb4 is the fourth stage. Furthermore, in the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, the boom member Bb4 becomes a telescopic boom that can extend and retract in the longitudinal direction of the multi-stage boom 1 relative to the boom member B1, which is the base boom member. Therefore, in the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, the dimension of the multi-stage boom 1 along the longitudinal direction changes when any of the boom members B2, B3, Bb4 extends or contracts in the longitudinal direction. Furthermore, in the front portion 3B, a boom head 5B is provided at the front end of the boom member Bb4.

[0017] In the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, among the boom members Bi, Bbk, the first boom member B1 is disposed on the outermost side, and the boom member Bb4 is disposed on the innermost side. Then, in a state in which the front portion 3B is attached to the rear portion 2, among the boom members Bi, Bbk, the boom member Bb4 is disposed on the innermost side as the stage number becomes larger. Also, in the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, the front end is formed by the boom head 5B of the boom member Bb4. Then, in a state in which the front portion 3B is attached to the rear portion 2, among the boom members Bi, Bbk, the front end is located further forward as the stage number becomes larger. Due to the above-mentioned configuration, in the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, the boom member Bb4 is one stage forward of the boom member B3. Furthermore, when the front section 3B is attached to the rear section 2, the boom member Bb4 becomes the frontmost stage (final stage) boom member Bbγ in the multi-stage boom 1 (front section 3B). Therefore, when the front section 3B is attached to the rear section 2, the number of stages of the multi-stage boom 1 is four. Furthermore, among the boom members Bbk of the front section 3B attached to the rear section 2, the boom member Bb4 becomes the rearmost stage boom member Bbβ.

[0018] A telescopic cylinder (boom telescopic cylinder) 10 is disposed inside the multi-stage boom 1. The telescopic cylinder 10 includes a cylinder rod 11 and a cylinder tube 12. The cylinder rod 11 is connected to the first boom member B1, which is a base boom member, via a connecting member 15 such as a connecting pin. When the cylinder tube 12 moves along the longitudinal direction of the multi-stage boom 1 relative to the cylinder rod 11, the telescopic cylinder 10 extends or contracts in the longitudinal direction of the multi-stage boom 1. In addition, a connecting member 16 such as a grip pin is provided on the end of the cylinder tube 12 on the cylinder rod 11 side, i.e., the rear end of the cylinder tube 12. When the telescopic cylinder 10 extends or contracts, the connecting member 16 can move along the longitudinal direction of the multi-stage boom 1 together with the cylinder tube 12 relative to the cylinder rod 11 and the connecting member 15.

[0019] In a state where the front section 3A is attached to the rear section 2, the cylinder tube 12 can be selectively connected to any one of the boom members (telescopic boom members) B2, B3 of the rear section 2 and the boom member (telescopic boom member) Baj of the front section 3A through the connecting member 16. Then, by extending or contracting the telescopic cylinder 10 with the cylinder tube 12 connected to any one of the boom members B2, B3, Baj, the boom member (corresponding one of B2, B3, Baj) to which the cylinder tube 12 is connected extends or contracts in the longitudinal direction of the multi-stage boom 1 relative to the boom member B1. As a result, in the multi-stage boom 1 with the front section 3A attached to the rear section 2, the length (dimension) of the multi-stage boom 1 in the longitudinal direction changes. Here, in the state of FIG. 1(a), the cylinder tube 12 is connected to the boom member Ba6, and by extending or contracting the telescopic cylinder 10, the boom member Ba6 can be telescopic relative to the boom member B1. When any one of the boom members B2, B3, Baj is extended or retracted, the cylinder tube 12 is connected to the boom member to be extended or retracted (the corresponding one of B2, B3, Baj) as described above, and the connection by the lock pin (not shown) to the boom member one stage rearward of the boom member to be extended or retracted (the corresponding one of B2, B3, Baj) is released.

[0020] In a state where the front section 3B is attached to the rear section 2, the cylinder tube 12 can be selectively connected to any one of the boom members (telescopic boom members) B2, B3 of the rear section 2 and the boom member (telescopic boom member) Bb4 of the front section 3B through the connecting member 16. Then, by extending or contracting the telescopic cylinder 10 in a state where the cylinder tube 12 is connected to any one of the boom members B2, B3, Bb4, the boom member (corresponding one of B2, B3, Bb4) to which the cylinder tube 12 is connected extends or contracts in the longitudinal direction of the multi-stage boom 1 relative to the boom member B1. As a result, in the multi-stage boom 1 in which the front section 3B is attached to the rear section 2, the length (dimension) of the multi-stage boom 1 in the longitudinal direction changes. Here, in the state shown in FIG. 1(b), the cylinder tube 12 is connected to the boom member Bb4, and by extending or contracting the telescopic cylinder 10, the boom member Bb4 can be extended or contracted relative to the boom member B1. When any one of the boom members B2, B3, Bb4 is extended or retracted, the cylinder tube 12 is connected to the boom member to be extended or retracted (the corresponding one of B2, B3, Bb4) as described above, and the connection by the lock pin to the boom member one stage rearward of the boom member to be extended or retracted (the corresponding one of B2, B3, Bb4) is released.

[0021] When both the front sections 3A and 3B are separated from the rear section 2, the cylinder tube 12 can be selectively connected to one of the boom members (telescopic boom members) B2 and B3 of the rear section 2 via the connecting member 16. When the cylinder tube 12 is connected to one of the boom members B2 and B3, the telescopic cylinder 10 is extended or retracted, so that the boom member (corresponding one of B2 and B3) to which the cylinder tube 12 is connected extends or retracts in the longitudinal direction of the multi-stage boom 1 relative to the boom member B1. As a result, the length (dimension) of the multi-stage boom 1 in the longitudinal direction changes in the multi-stage boom 1 formed only from the rear section 2. Here, in the state shown in FIG. 1(c), the cylinder tube 12 is connected to the boom member B3, and the telescopic cylinder 10 is extended or retracted, so that the boom member B3 can be telescopic relative to the boom member B1. When extending or retracting one of the boom members B2, B3, the cylinder tube 12 is connected to the boom member to be extended or retracted (the corresponding one of B2, B3) as described above, and the connection by the lock pin to the boom member one stage rearward of the boom member to be extended or retracted (the corresponding one of B2, B3) is released.

[0022] Fig. 1(a) shows the boom members (telescopic boom members) B2, B3, and Baj in their most contracted state (0% extension rate), Fig. 1(b) shows the boom members (telescopic boom members) B2, B3, and Bb4 in their most contracted state (0% extension rate), and Fig. 1(c) shows the boom members (telescopic boom members) B2 and B3 in their most contracted state (0% extension rate).

[0023] In this embodiment, a reel 21 is installed on the boom member (base boom member) B1 of the rear section 2. In the multi-stage boom 1, a cord 22 is extended from the reel 21 of the rear section 2 toward the front side. A connector 23 is provided on the cord 22 at an extended end from the reel 21, that is, at an end distal to the reel 21. In the multi-stage boom 1 in which the front section 3A is attached to the rear section 2, the connector 23 (extended end) of the cord 22 is connectable to the boom head 5A of the boom member Ba6 of the front section 3A. In the multi-stage boom 1 in which the front section 3B is attached to the rear section 2, the connector 23 (extended end) of the cord 22 is connectable to the boom head 5B of the boom member Bb4 of the front section 3B. Therefore, the connector 23 of the cord 22 is selectively connectable to any one of the multiple types of front sections 3A, 3B. Furthermore, in a multi-stage boom 1 in which both of the front sections 3A, 3B are separated from the rear section 2, the connector 23 (extended end) of the cord 22 is connectable to the boom member B3 of the rear section 2. Note that in a multi-stage boom 1 in which both of the front sections 3A, 3B are separated from the rear section 2, the connector 23 of the cord 22 in the rear section 2 may be connectable to either one of the boom members B1 or B2 instead of the boom member B3.

[0024] Next, the operation of separating the front section 3A from the rear section 2 will be described with reference to Figs. 2(a)-(g). In the operation of separating the front section 3A from the rear section 2, first, as shown in Fig. 2(a), each of the boom members (telescopic boom members) B2, B3, and Baj is brought to the most contracted state (0% extension rate). At this time, the connector 23 (extended end) of the cord 22 is connected to the boom member Ba6, which is the most forward boom member Baγ in the front section 3A. Then, the cylinder tube 12 of the telescopic cylinder 10 is connected to the boom member Ba4, which is the most rear boom member Baβ in the front section 3A, via the connecting member 16. Then, as shown in Fig. 2(b), the telescopic cylinder 10 is extended with the cylinder tube 12 connected to the boom member Ba4, and the boom member Ba4 is extended to the most extended state (100% extension rate). When the boom member Ba4 reaches its most extended state, the connection of the cylinder tube 12 to the boom member Ba4 is released. Then, as shown in Fig. 2(c), after the cylinder tube 12 is contracted in a state in which the cylinder tube 12 is not connected to any of the boom members B2, B3, or Baj, the cylinder tube 12 of the telescopic cylinder 10 is connected to the boom member B3, which is the frontmost boom member Bα in the rear section 2, via the connecting member 16.

[0025] Then, as shown in FIG. 2(d), the telescopic cylinder 10 is extended with the cylinder tube 12 connected to the boom member B3, and the boom member B3 is extended to a predetermined telescopic state, such as a state of 50% extension rate. As a result, the boom member Ba4, which is the rearmost boom member Baβ in the front section 3A, is in a most extended state, and the boom member B3, which is the frontmost boom member Bα in the rear section 2, is in a predetermined telescopic state. When the boom member B3 is in the predetermined telescopic state, a lock pin (not shown) that connects the boom member Ba4 to the boom member B3 is exposed at the front end of the boom member B3. Then, when each of the boom members B3 and Ba4 is in the telescopic state shown in FIG. 2(d), the connector 23 (extended end) of the cord 22 is removed from the boom member Ba6 in the front section 3A and connected to the boom member B3 in the rear section 2. That is, the connector 23 is removed from the position indicated by the solid line in Fig. 2(d) and connected to the position indicated by the dashed line in Fig. 2(d). Then, as shown in Fig. 2(e), when the boom members B3 and Ba4 are in the extended and contracted state shown in Fig. 2(d), the connection of the boom member Ba4 to the boom member B3 by the lock pin (not shown) is forcibly released, and the front portion 3A (boom member Baj) is lifted vertically upward by a crane separate from the crane on which the multi-stage boom 1 is mounted.

[0026] Then, as shown in FIG. 2(f), the telescopic cylinder 10 is contracted while the front section 3A is lifted. At this time, since the cylinder tube 12 is connected to the boom member B3, the boom member B3 contracts from a predetermined telescopic state (e.g., a state of 50% extension rate) in response to the contraction of the telescopic cylinder 10. As the boom member B3 contracts from the predetermined telescopic state, the front section 3A is separated from the rear section 2. Note that in FIG. 2(f), the boom member B3 is shown in a state contracted from a predetermined contracted state, for example, a state of 15% extension rate. Then, as shown in FIG. 2(g), the telescopic cylinder 10 is further contracted to contract the boom member B3 to the most contracted state (a state of 0% extension rate), thereby completing the operation of separating the front section 3A from the rear section 2.

[0027] The work of attaching the front portion 3A to the rear portion 2 is performed in the reverse order to the work of separating the front portion 3A from the rear portion 2. That is, in the work of separating the front portion 3A from the rear portion 2, the state of the multi-stage boom 1 changes in the order of Fig. 2(a), Fig. 2(b), ..., Fig. 2(f), Fig. 2(g), whereas in the work of attaching the front portion 3A to the rear portion 2, the state of the multi-stage boom 1 changes in the order of Fig. 2(g), Fig. 2(f), ..., Fig. 2(b), Fig. 2(a). In addition, the work of separating the front portion 3B from the rear portion 2 is performed in the same manner as the work of separating the front portion 3A from the rear portion 2. In addition, the work of attaching the front portion 3B to the rear portion 2 is performed in the same manner as the work of attaching the front portion 3A to the rear portion 2.

[0028] FIG. 3 shows a system provided with a boom control device 20 that controls the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1. As shown in FIG. 3, the boom control device 20 includes a cord 22 having a connector 23 at an end (distal end) extending from a reel 21. The boom control device 20 also includes a controller 25. The controller 25 includes a processor and a storage medium, and the processor is an integrated circuit or circuitry including a CPU (Central Processing Unit), an ASIC (Application specific integrated circuit), an FPGA (Field Programmable Gate Array), or the like. Only one processor may be provided, or multiple processors may be provided. Processing in the processor is performed according to a program stored in the processor or the storage medium. The storage medium also stores a processing program used by the processor, and parameters, functions, tables, and the like used in the calculations in the processor.

[0029] The controller 25 acquires information indicating the history of extension and contraction of each of the telescopic boom members constituting the multi-stage boom 1. For example, when the front section 3A is attached to the rear section 2, the controller 25 acquires the history of extension and contraction of each of the boom members (telescopic boom members) B2, B3, and Baj, and acquires information indicating the real-time extension and contraction state (extension rate, etc.) of each of the boom members B2, B3, and Baj. Similarly, when both of the front sections 3A and 3B are separated from the rear section 2, the controller 25 acquires the history of extension and contraction of each of the boom members (telescopic boom members) B2 and B3, and acquires information indicating the real-time extension and contraction state (extension rate, etc.) of each of the boom members B2 and B3. The history of extension and contraction of each of the telescopic boom members can be calculated based on the history of the connection state of the cylinder tube 12 of the telescopic cylinder 10 with each of the telescopic boom members, the history of the length of the multi-stage boom 1 in the longitudinal direction, and the history of the telescopic cylinder 10. Further, through a user interface (not shown) or the like, an operator or the like can input operation commands related to the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1. The controller 25 acquires the operation commands input through the user interface or the like.

[0030] The controller 25 can communicate with the device attached to the connection destination of the connector 23, and acquires information related to the device attached to the connection destination of the connector 23 based on a signal transmitted from the device via the cord 22. For example, when the connector 23 (extended end) is connected to the front side portion 3A, the controller 25 can communicate with the device attached to the boom head 5A of the boom member Ba6 (Baγ), and when the connector 23 (extended end) is connected to the front side portion 3B, the controller 25 can communicate with the device attached to the boom head 5B of the boom member Bb4 (Bbγ). Examples of the devices attached to the boom heads 5A and 5B include switches that detect overwinding of the ropes that suspend the hooks from each of the boom heads 5A and 5B, and sensors that detect parameters related to the multi-stage boom 1, such as the ground angles of each of the boom heads 5A and 5B.

[0031] The controller 25 determines whether the connector 23 (extended end) of the cord 22 is connected based on information transmitted through the cord 22, including signals transmitted through the cord 22. Fig. 4 shows an example of a determination of the connection of the connector 23 of the cord 22 by the controller 25. In the example of Fig. 4, in each of a state in which the connector 23 is connected to the front part 3A, a state in which the connector 23 is connected to the front part 3B, and a state in which the connector 23 is connected to the rear part 2, an address of a device attached to a connection destination of the connector 23 is transmitted through the cord 22 by serial communication such as communication according to the CAN (controller area network) standard. Unique addresses different from one another are set for the device attached to the front part 3A, the device attached to the front part 3B, and the device attached to the rear part 2. In the example of FIG. 4, when the controller 25 acquires "1111" as the address of the device, it determines that the connection destination of the connector 23 (extended end) of the cord 22 is the front part 3A (boom member Ba6), and when the controller 25 acquires "2222" as the address of the device, it determines that the connection destination of the connector 23 (extended end) of the cord 22 is the front part 3B (boom member Bb4). When the controller 25 acquires "3333" as the address of the device, it determines that the connector 23 of the cord 22 is not connected to either of the front parts 3A and 3B, and determines that the connection destination of the connector 23 (extended end) of the cord 22 is the rear part 2 (boom member B3). When the signal is not transmitted through the cord 22 and the address of the device is not acquired, the controller 25 determines that a break in the cord 22 or a failure of the device has occurred, and determines that a detection failure has occurred for the connection destination of the cord 22.

[0032] In one example, when the above-mentioned device is not attached to the rear part 2 and the connector 23 of the cord 22 is connected to the rear part 2, the controller 25 does not communicate via the cord 22. In this example, when a signal is not transmitted via the cord 22 and the address of the device is not acquired, the controller 25 determines that the connector 23 of the cord 22 is not connected to either of the front parts 3A, 3B, and determines that the connection destination of the connector 23 (extended end) of the cord 22 is the rear part 2 (boom member B3).

[0033] Fig. 5 shows another example of the determination by the controller 25 regarding the connection of the connector 23 of the cord 22, different from that shown in Fig. 4. In the example shown in Fig. 5, the connector 23 of the cord 22 has at least three terminals, namely, a terminal No. 1, a terminal No. 2, and a terminal No. 3. When the terminal No. 1 is energized and a signal or the like from an appliance is transmitted through the terminal No. 1 of the cord 22, the controller 25 determines that the connection destination of the connector 23 (extended end) of the cord 22 is the front part 3A (boom member Ba6). When the terminal No. 2 is energized and a signal or the like from an appliance is transmitted through the terminal No. 2 of the cord 22, the controller 25 determines that the connection destination of the connector 23 (extended end) of the cord 22 is the front part 3B (boom member Bb4). Then, when the terminal 3 is energized and a signal or the like is transmitted through the terminal 3 in the cord 22, the controller 25 determines that the connector 23 of the cord 22 is not connected to either of the front portions 3A, 3B, and determines, for example, that the connection destination of the connector 23 (extended end) of the cord 22 is the rear portion 2 (boom member B3).When none of the terminals 1 to 3 is energized and a signal or the like is not transmitted through any of the terminals 1 to 3, the controller 25 determines that a break in the cord 22 or a failure in the equipment has occurred, and determines that a detection failure has occurred with respect to the connection destination of the cord 22.

[0034] In one example, the connector 23 is provided with only the terminals 1 and 2, without the terminal 3. In this case, similar to the example of FIG. 5, the controller 25 determines that the connector 23 is connected to the front part 3A and also determines that the connector 23 is connected to the front part 3B. However, in this example, the controller 25 determines that the connector 23 is not connected to either the front part 3A or 3B based on whether or not both the terminals 1 and 2 are energized, or whether or not both the terminals 1 and 2 are energized, and determines that the connector 23 (extended end) of the cord 22 is connected to the rear part 2, for example. As described above, in this embodiment including the example of FIG. 4 and the example of FIG. 5, the controller 25 determines the connection (connection destination) of the connector 23 (extended end) of the cord 22 based on the presence or absence of a signal transmitted through the cord 22, the address of the device transmitted through the cord 22, and the transmission path in the cord 22 of the signal transmitted through the cord 22.

[0035] The controller 25 determines the attachment state (connection state) between each of the front parts 3A, 3B and the rear part 2 based on the determination result of the connection (connection destination) of the connector 23 of the cord 22. In this embodiment, the controller 25 determines which of the three attachment states shown in Figs. 1(a) to (c) exists. Fig. 6 shows an example of a determination process of the attachment state between each of the front parts 3A, 3B and the rear part 2 by the controller 25. The determination process of Fig. 6 is repeatedly performed over time while the controller 25 controls the operation of the multi-stage boom 1. When the determination process of Fig. 6 is started, the controller 25 determines whether the connector 23 (extended end) of the cord 22 is connected to either of the front parts 3A, 3B (S101). The connection destination of the connector 23 is determined in the same manner as any of the above-mentioned examples. When the connector 23 is not connected to either of the front portions 3A, 3B (S101-No), the controller 25 determines whether or not the connector 23 (extended end) of the cord 22 is connected to the rear portion 2 (S102). When the connector 23 is connected to the rear portion 2 (S102-Yes), it is determined that both of the front portions 3A, 3B are separated from the rear portion 2 (S103). Therefore, it is determined that the number of stages of the multi-stage boom 1 is three. On the other hand, when the connector 23 is not connected to the rear portion 2 (S102-No), it is determined that a detection failure has occurred with respect to the connection destination of the connector 23 of the cord 22 (S104).

[0036] In S101, if the connector 23 is connected to either the front portion 3A or 3B (S101-Yes), the controller 25 determines that one of the front portions 3A and 3B is attached to the rear portion 2. Then, the controller 25 determines whether the connector 23 (extended end) of the cord 22 is connected to the front portion 3A (S105). If the connector 23 is connected to the front portion 3A (S105-Yes), the controller 25 determines that the front portion 3A is attached to the rear portion 2 (S106). In this case, it is determined that the number of stages of the multi-stage boom 1 is six. On the other hand, if the connector 23 is not connected to the front portion 3A (S105-No), the controller 25 determines that the connector 23 is connected to the front portion 3B, and determines that the front portion 3B is attached to the rear portion 2 (S107). In this case, it is determined that the number of stages of the multi-stage boom 1 is four. Therefore, when it is determined that either the front side section 3A, 3B is attached to the rear side section 2, the controller 25 determines which type of the multiple types of front side section 3A, 3B is attached to the rear side section 2 based on the connection destination of the connector 23 (extended end) of the cord 22.

[0037] In addition, in another example, when the connector 23 is not connected to either of the front parts 3A, 3B in S101 (S101-No), the controller 25 does not perform the process of S102. In this example, when the connector 23 is not connected to either of the front parts 3A, 3B in S101 (S101-No), the controller 25 determines that both of the front parts 3A, 3B are separated from the rear part 2.

[0038] The controller 25 controls the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1, based on the determination result of whether or not either of the front parts 3A, 3B is attached to the rear part 2, i.e., based on the determination result of whether or not either of the front parts 3A, 3B is separated from the rear part 2. When either of the front parts 3A, 3B is attached to the rear part 2, the controller 25 controls the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1, based on the determination result of the type of the front part (3A or 3B) attached to the rear part 2, i.e., based on the determination result of which of the front parts 3A, 3B is attached to the rear part 2. Here, since the number of stages of the multi-stage boom 1 differs according to the attachment state (connected state) of each of the front parts 3A, 3B to the rear part 2 as described above, the weight of the multi-stage boom 1 and the length in the longitudinal direction of the multi-stage boom 1 differ according to the attachment state of each of the front parts 3A, 3B to the rear part 2. For this reason, the controller 25 controls the operation of the multi-stage boom 1, including extension and contraction of the multi-stage boom 1, in response to the real-time attachment state of each of the front sections 3A, 3B to the rear section 2. The control of the operation of the multi-stage boom 1 is performed based on information indicating the history of extension and contraction of each of the telescopic boom members, operation commands related to the operation of the multi-stage boom 1, in addition to the determination result of the attachment state of each of the front sections 3A, 3B to the rear section 2.

[0039] As shown in FIG. 3 etc., the controller 25 controls the extension and retraction of the telescopic cylinder 10, i.e., the operation of the telescopic cylinder 10, thereby controlling the extension and retraction of the multi-stage boom 1. In controlling the operation of the telescopic cylinder 10, i.e., in controlling the extension and retraction of the multi-stage boom 1, the controller 25 sets the extension and retraction range of the telescopic cylinder 10 in accordance with the real-time attachment state of each of the front sections 3A, 3B to the rear section 2. The controller 25 then controls the operation of the telescopic cylinder 10 so that the telescopic cylinder 10 only extends and retracts within the set extension and retraction range. The set extension and retraction range of the telescopic cylinder 10 differs depending on the attachment state of each of the front sections 3A, 3B to the rear section 2. In other words, the set extension and retraction range of the telescopic cylinder 10 differs depending on the attachment state of the front sections 3A, 3B to the rear section 2, the state in which the front section 3A is attached to the rear section 2, the state in which the front section 3B is attached to the rear section 2, and the state in which both the front sections 3A, 3B are separated from the rear section 2.

[0040] When the front section 3A is attached to the rear section 2, in a state where the cylinder tube 12 (connecting member 16) is not connected to any of the boom members B2, B3, or Baj, the telescopic range of the telescopic cylinder 10, i.e., the range where the connecting member 16 can move in the longitudinal direction of the multi-stage boom 1, is set to the range between the position where the cylinder tube 12 can be connected to the boom member B2 and the position where the cylinder tube 12 can be connected to the boom member Ba6. For example, in a state where each of the boom members (telescopic boom members) B2, B3, and Baj is fully contracted (extension rate 0%) as shown in Fig. 1(a), the telescopic range of the telescopic cylinder 10 in a state where the cylinder tube 12 is not connected to any of the boom members B2, B3, or Baj is set to a range δa. Furthermore, when the front section 3B is attached to the rear section 2, in a state where the cylinder tube 12 (connecting member 16) is not connected to any of the boom members B2, B3, Bb4, the telescopic range of the telescopic cylinder 10 (the range where the connecting member 16 can move in the longitudinal direction of the multi-stage boom 1) is set to the range between the position where the cylinder tube 12 can be connected to the boom member B2 and the position where the cylinder tube 12 can be connected to the boom member Bb4. For example, in a state where each of the boom members (telescopic boom members) B2, B3, Bb4 is fully contracted as shown in Fig. 1(b), the telescopic range of the telescopic cylinder 10 in a state where the cylinder tube 12 is not connected to any of the boom members B2, B3, Bb4 is set to a range δb. When both of the front sections 3A and 3B are separated from the rear section 2, and the cylinder tube 12 (connecting member 16) is not connected to either of the boom members B2 and B3, the telescopic range of the telescopic cylinder 10 is set to a range between a position where the cylinder tube 12 can be connected to the boom member B2 and a position where the cylinder tube 12 can be connected to the boom member B3. For example, when the boom members (telescopic boom members) B2 and B3 are in their most contracted state as shown in Fig. 1(c), a range δc is set as the telescopic range of the telescopic cylinder 10 when the cylinder tube 12 is not connected to either of the boom members B2 and B3.

[0041] As shown in FIG. 3 and other figures, the controller 25 that controls the operation of the multi-stage boom 1 controls the hoisting of the multi-stage boom 1 by controlling the operation of a boom hoisting cylinder (derrick cylinder). In controlling the operation of the multi-stage boom 1, including the extension and extension and hoisting of the multi-stage boom 1, the controller 25 calculates the real-time working radius of the multi-stage boom 1, and controls the extension and hoisting of the multi-stage boom 1 so that the multi-stage boom 1 does not interfere with obstacles around the crane. The controller 25 also calculates the load (actual load) that is applied in real time to the multi-stage boom 1 due to a hoisted load, etc., and calculates and sets a limit value (upper limit value) for the load that can be applied to the multi-stage boom 1. The controller 25 issues a warning or the like when the difference between the real-time load and the limit value falls below a threshold value, and forcibly stops the operation of the multi-stage boom 1, including the extension and hoisting of the multi-stage boom 1, when the real-time load exceeds the limit value.

[0042] Here, the real-time working radius of the multi-stage boom 1 is calculated based on the length of the multi-stage boom 1 in the longitudinal direction, etc., and the load (actual load) applied to the multi-stage boom 1 in real time and the limit value of the load applied to the multi-stage boom 1 are calculated based on the length of the multi-stage boom 1 in the longitudinal direction and the weight of the multi-stage boom 1, etc. For this reason, the calculated real-time working radius and load (actual load) of the multi-stage boom 1 and the set limit value of the load of the multi-stage boom 1 differ depending on the respective attachment states of the front portions 3A, 3B to the rear portion 2. That is, in a state where the front portion 3A is attached to the rear portion 2, a state where the front portion 3B is attached to the rear portion 2, and a state where both the front portions 3A, 3B are separated from the rear portion 2, the calculation results of the real-time working radius and load of the multi-stage boom 1 differ from each other. Furthermore, when the front portion 3A is attached to the rear portion 2, when the front portion 3B is attached to the rear portion 2, and when both the front portions 3A and 3B are separated from the rear portion 2, the limit values ​​set for the load of the multi-stage boom 1 are also different from one another.

[0043] In this embodiment, the controller 25 determines that the front parts 3A, 3B are attached to the rear part 2 based on the fact that the extended end (connector 23) of the cord 22 is connected to either of the front parts 3A, 3B. Then, the controller 25 determines that both of the front parts 3A, 3B are separated from the rear part 2 based at least on the fact that the extended end of the cord 22 is not connected to either of the front parts 3A, 3B. Then, the controller 25 controls the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1, based on the result of the determination as to whether or not either of the front parts 3A, 3B is attached to the rear part 2. Since the determination is performed as described above, it is appropriately determined whether or not either of the front parts 3A, 3B is attached to the rear part 2. Then, the operation of the multi-stage boom 1 is controlled based on the appropriately determined determination result, so that the operation of the multi-stage boom 1 is appropriately and safely controlled in accordance with whether or not either of the front parts 3A, 3B is attached to the rear part 2.

[0044] In this embodiment, the controller 25 determines that both the front portions 3A and 3B are separated from the rear portion 2 based on the fact that the extended end of the cord 22 (connector 23) is not connected to either of the front portions 3A and 3B and that the extended end of the cord 22 is connected to the rear portion 2. This allows the occurrence of a detection failure regarding the connection destination of the extended end of the cord 22 to be appropriately determined.

[0045] Furthermore, in this embodiment, when it is determined that either the front portion 3A or 3B is attached to the rear portion 2, the controller 25 determines which of the multiple types of front portions 3A or 3B is attached to the rear portion 2 based on the connection destination of the extended end of the cord 22. Then, the controller 25 controls the operation of the multi-stage boom 1 based on the determination result regarding the type of the front portion (3A or 3B) attached to the rear portion 2. Since the determination is performed as described above, it is appropriately determined which type of the front portion 3A or 3B is attached to the rear portion 2. Then, since the operation of the multi-stage boom 1 is controlled based on the appropriately determined determination result, the operation of the multi-stage boom 1 is appropriately and safely controlled in accordance with the type of the front portion (3A or 3B) attached to the rear portion 2.

[0046] As described above, in this embodiment, the controller 25 judges the attachment state of each of the front sections 3A, 3B to the rear section 2 based on the judgment result of the connection of the extended end of the cord 22. Therefore, the attachment state of each of the front sections 3A, 3B to the rear section 2 is appropriately judged. Then, the operation of the multi-stage boom 1 is controlled based on the appropriately judged judgment result, so that the operation of the multi-stage boom 1 is appropriately controlled in accordance with the real-time attachment state of each of the front sections 3A, 3B to the rear section 2. For example, the controller 25 sets the telescopic range of the telescopic cylinder 10 described above based on the judgment result of the attachment state of each of the front sections 3A, 3B to the rear section 2. As a result, the telescopic range of the telescopic cylinder 10 is appropriately set to a range that corresponds to the real-time attachment state of each of the front sections 3A, 3B to the rear section 2. Therefore, the operation of the telescopic cylinder 10 is controlled so that the telescopic cylinder 10 extends and retracts within the set telescopic range, so that the operation of the telescopic cylinder 10 is appropriately controlled, and the telescopic operation of the multi-stage boom 1 is appropriately controlled. By properly controlling the operation of the telescopic cylinder 10 and the extension and retraction of the multi-stage boom 1, it is possible to effectively prevent the telescopic cylinder 10 from being overextended beyond the appropriate telescopic range. This effectively prevents the cylinder tube 12 from coming out of the cylinder guide and the front end of the cylinder tube 12 from interfering with the boom head (5A or 5B).

[0047] Furthermore, the controller 25 acquires the length of the multistage boom 1 in the longitudinal direction and the weight of the multistage boom 1 based on the determination result of the attachment state of each of the front sections 3A, 3B to the rear section 2, and calculates the real-time working radius of the multistage boom 1, the load (actual load) applied to the multistage boom 1 in real time, and a limit value (upper limit value) for the load applied to the multistage boom 1. Therefore, values ​​corresponding to the real-time attachment state of each of the front sections 3A, 3B to the rear section 2 are appropriately calculated as the working radius of the multistage boom 1, the load (actual load) of the multistage boom 1, and the limit value for the load of the multistage boom 1. Therefore, by controlling the extension and contraction, elevation, etc. of the multistage boom 1 based on the calculated working radius of the multistage boom 1, interference of the multistage boom 1 with obstacles around the crane is effectively prevented. Furthermore, by controlling the operation of the multi-stage boom 1 based on the calculated load of the multi-stage boom 1 and the limit value for the load of the multi-stage boom 1, an appropriate warning is issued and the operation of the multi-stage boom 1 is appropriately forcibly stopped in accordance with the real-time attachment state of each of the front sections 3A, 3B to the rear section 2. This effectively prevents the crane from getting into a position that makes it prone to tipping over, etc.

[0048] Further, the attachment state of each of the front parts 3A, 3B to the rear part 2 is determined based on the connection destination of the extension end of the cord 22, and information indicating the attachment state of each of the front parts 3A, 3B to the rear part 2 is not input by an operator through a user interface or the like. Therefore, it is possible to effectively prevent the multi-stage boom 1 from malfunctioning due to an erroneous input of information indicating the attachment state of each of the front parts 3A, 3B to the rear part 2. Furthermore, the controller 25 determines the connection of the extension end of the cord 22 based on the presence or absence of a signal transmitted through the cord 22, the address of the device transmitted through the cord 22, and the transmission path in the cord 22 of the signal transmitted through the cord 22. As a result, the connection destination of the extension end of the cord 22 is appropriately determined, and the attachment state of each of the front parts 3A, 3B to the rear part 2 is further appropriately determined.

[0049] (Modification) In a modified example shown in FIG. 7, the boom control device 20 that controls the operation of the multi-stage boom 1 includes a boom length measuring unit 26 that measures the length of the multi-stage boom 1 in the longitudinal direction. The boom length measuring unit 26 is formed of a measuring instrument including a sensor, a processor, and the like. In this modified example, the reel 21 is also installed on the boom member (base boom member) B1 of the rear section 2, and a cord 22 is extended from the reel 21 toward the front side of the multi-stage boom 1. However, in this modified example, the reel 21 is set at the rear end of the boom member B1 of the first stage. In this modified example, the extended end (distal end) of the cord 22 from the reel 21 is connected to the boom member (telescopic boom member) of the most forward stage of the multi-stage boom 1 attached to the rotating body. For this reason, in a multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2, the extended end (distal end) of the cord 22 from the reel 21 is connected to the boom head 5A of the boom member Ba6 of the front portion 3A, and in a multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2, the extended end of the cord 22 is connected to the boom head 5B of the boom member Bb4 of the front portion 3B. Also, in a multi-stage boom 1 in which both of the front portions 3A and 3B are separated from the rear portion 2, the extended end of the cord 22 is connected to the front end of the boom member B3 of the rear portion 2.

[0050] In Code 22, the extension length from the reel 21 to the extended end (distal end) changes according to the connection destination of the extended end from the reel 21, which is installed in the rear portion 2. That is, the extension length of the Code 22 changes according to whether the extended end of the Code 22 is connected to any of the front portions 3A, 3B and the rear portion 2. In this modification, the boom length measurement unit 26 measures the length of the multi-stage boom 1 in the longitudinal direction based on the extension length of the Code 22 from the rear portion 2 (reel 21) to the extended end. The controller 25 acquires the measurement result of the boom length measurement unit 26 regarding the length of the multi-stage boom 1. Also in this modification, as in the above-described embodiment and the like, the controller 25 acquires information indicating the history of the expansion and contraction of each of the telescopic boom members constituting the multi-stage boom 1, and also acquires the operation commands input through the user interface or the like. Therefore, the controller 25 acquires information indicating the history of the expansion and contraction, such as the history of the expansion rate, for each of the telescopic boom members, that is, for each of the boom members of the second stage and the stages in front of the second stage. As described above, the history of the expansion and contraction of each of the telescopic boom members can be calculated based on the history of the connection state of the cylinder tube 12 of the telescopic cylinder 10 with each of the telescopic boom members, the history of the length of the multi-stage boom 1 in the longitudinal direction, and the history of the expansion and contraction of the telescopic cylinder 10, and the like.

[0051] In this modification, the controller 25 determines the connection of the extended end of the Code 22 based on the measurement result of the length of the multi-stage boom 1 by the boom length measurement unit 26 and the history of the expansion and contraction of each of the boom members (telescopic boom members) B2, B3 of the rear portion 2 and the boom members (telescopic boom members) of the front portion (3A or 3B) attached to the rear portion 2. That is, based on the length of the multi-stage boom 1 and the history of the expansion and contraction (for example, the history of the expansion rate) of each of the boom members of the second stage and the stages in front of the second stage, the connection destination of the extended end of the Code 22 is determined. FIG. 8 shows an example of the determination by the controller 25 of the connection of the extended end of the Code 22 in this modification. Here, as the length of the multi-stage boom 1, values L1 to L5 are defined, and it is assumed that L1 < L2 < L3 < L4 < L5 holds.

[0052] In the example of FIG. 8, it is assumed that the controller 25 acquires information indicating that the extension rate of the third stage is 50%, the extension rate of the fourth stage is 100%, and the extension rate of stages other than the third and fourth stages is 0% as the history of extension of each boom member (telescopic boom member). In this case, if the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L5, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side portion 3A (boom member Ba6), and if the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L4, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side portion 3B (boom member Bb4). Note that in the state of FIG. 2(d) etc., the length of the multi-stage boom 1 becomes the same or substantially the same as the value L5. Then, when the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L1, the controller 25 determines that the connection destination of the extended end of the cord 22 is the rear section 2 (boom member B3). When the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L1, the controller 25 determines that the stage is immediately after the corresponding one of the front sections 3A, 3B has been separated from the rear section 2. For example, the state changes in the order of Figures 2(a), 2(b), 2(c), and 2(d), and it is determined that the stage is immediately after the front section 3A has been detached from the rear section 2.

[0053] Also, in the example of FIG. 8, it is assumed that the controller 25 acquires information indicating that the extension rate of the third stage is 50% and the extension rate of the stages other than the third stage is 0% as the history of extension and contraction of each boom member (telescopic boom member). In this case, if the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L1, the controller 25 determines that the connection destination of the extended end of the cord 22 is the rear side section 2 (boom member B3). Note that in the state of FIG. 2(e) and the like, the length of the rear side section 2 is the same or substantially the same as the value L1. Then, if the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L3, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side section 3A (boom member Ba6), and if the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L2, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side section 3B (boom member Bb4).

[0054] Also, when the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L5, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side section 3A (boom member Ba6). However, when the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L5, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side section 3A (boom member Ba6). In other words, the state changes in the order of FIG. 2(g), FIG. 2(f), FIG. 2(e), and FIG. 2(d), and it is determined that the connection destination is the front side section 3A immediately after it is attached to the rear side section 2. Also, when the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L4, the controller 25 determines that the connection destination of the extended end of the cord 22 is the front side section 3B (boom member Bb4). However, when the measured value of the length of the multi-stage boom 1 is the same or substantially the same as the value L4, the controller 25 determines that the connection destination is the front side section 3B immediately after it is attached to the rear side section 2. Incidentally, immediately after the front section 3A is attached to the rear section 2, the controller 25 has not acquired information indicating the history of telescopic extension of each of the fourth stage and the stage forward of the fourth stage (telescopic boom member). Therefore, based on the information indicating that the extension rate of the third stage is 50% and that the extension rate of the stage numbers other than the third stage is 0%, and on the length of the multi-stage boom 1, it is determined whether or not it is the stage immediately after the front section 3A is attached to the rear section 2. Similarly, immediately after the front section 3B is attached to the rear section 2, the controller 25 has not acquired information indicating the history of telescopic extension of the fourth stage boom member (telescopic boom member). Therefore, based on the information indicating that the extension rate of the third stage is 50% and that the extension rate of the stage numbers other than the third stage is 0%, and on the length of the multi-stage boom 1, it is determined whether or not it is the stage immediately after the front section 3B is attached to the rear section 2.

[0055] Also, when the controller 25 acquires information different from the information shown in FIG. 8 as the history of extension and contraction of each boom member (telescopic boom member), the controller 25 determines the connection (connection destination) of the extended end of the cord 22 based on the measurement result of the length of the multi-stage boom 1 in the same manner as in the above-mentioned example. In this modification, the controller 25 also determines the attachment state (connection state) between each of the front parts 3A, 3B and the rear part 2 based on the determination result of the connection (connection destination) of the extended end of the cord 22. Therefore, the attachment state between each of the front parts 3A, 3B and the rear part 2 is determined by the determination process shown in FIG. 6. In this modification, the controller 25 also controls the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1, based on the determination result of whether or not either of the front parts 3A, 3B is attached to the rear part 2. And in this modified example, when either the front part 3A, 3B is attached to the rear part 2, the controller 25 controls the operation of the multi-stage boom 1, including the extension and contraction of the multi-stage boom 1, based on the determination result regarding the type of front part (3A or 3B) attached to the rear part 2.

[0056] As described above, in this modification as well, controller 25 determines the attachment state of each of front portions 3A, 3B to rear portion 2 based on the determination result regarding the connection of the extended ends of cord 22. Therefore, in this modification as well, the attachment state of each of front portions 3A, 3B to rear portion 2 is appropriately determined. Then, operation of multi-stage boom 1 is controlled based on the appropriately determined determination result, so that in this modification as well, operation of multi-stage boom 1 is appropriately controlled in response to the real-time attachment state of each of front portions 3A, 3B to rear portion 2.

[0057] Furthermore, in this modified example, the controller 25 determines the connection of the extended end of the cord 22 based on the measurement result of the length of the multi-stage boom 1 by the boom length measuring unit 26 and the history of extension and contraction of each of the boom members (telescopic boom members) B2, B3 of the rear section 2 and the boom member (telescopic boom member) of the front section (3A or 3B) attached to the rear section 2. This allows the connection destination of the extended end of the cord 22 to be appropriately determined, and the attachment state of each of the front sections 3A, 3B to the rear section 2 to be more appropriately determined.

[0058] In a modified example, the controller 25 may perform both the determination described above in the first embodiment and the determination described above in the modified examples of FIG. 7 and FIG. 8 for the connection (connection destination) of the extension end of the cord 22. In this case, the priority order of the determination results is set for the two determinations. If the determination results differ in the two determinations, the controller 25 uses the determination result with the higher priority order as the determination result for the connection (connection destination) of the extension end of the cord 22, and performs the determination of the attachment state between each of the front parts 3A, 3B and the rear part 2. In addition, by performing two determinations, even if a detection failure occurs in one of the two determinations for the connection destination of the extension end of the cord 22, the connection destination of the extension end of the cord 22 is appropriately determined by the other of the two determinations. Therefore, even if a detection failure occurs in one of the two determinations for the connection destination of the extension end of the cord 22, it is possible to appropriately determine the attachment state between each of the front parts 3A, 3B and the rear part 2.

[0059] In the above-mentioned embodiment, the rear section 2 is formed of one base boom member (B1) and two telescopic boom members (B2, B3), but the rear section 2 may include one base boom member and one or more telescopic boom members. In the above-mentioned embodiment, the front section 3A is formed of three telescopic boom members (Ba4-Ba6), and the front section 3B is formed of one telescopic boom member (Bb4), but each of the front sections 3A and 3B may include one or more telescopic boom members. In these cases, the attachment state (connection state) between each of the front sections 3A and 3B and the rear section 2 is determined in the same manner as in the above-mentioned embodiment. That is, the attachment state of each of the front sections 3A and 3B to the rear section 2 is appropriately determined based on the determination result of the connection of the extended end of the cord 22.

[0060] In the above-mentioned embodiment, the number of boom members Bbk provided in the front portion 3B is different from the number of boom members Baj provided in the front portion 3A. However, if the front portions 3A and 3B are different in type from each other, the number of boom members provided in the front portions 3A and 3B may be the same. In this case, the number of stages of the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2 is the same as the number of stages of the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2. However, the multi-stage boom 1 in which the front portion 3B is attached to the rear portion 2 is different from the multi-stage boom 1 in which the front portion 3A is attached to the rear portion 2 in one or more of the length in the longitudinal direction, weight, etc. In this case, the attachment state (connection state) between each of the front portions 3A and 3B and the rear portion 2 is determined in the same manner as in the above-mentioned embodiment.

[0061] In the above embodiment, any one of the two types of front parts 3A, 3B can be selectively attached to the rear part 2, but any one of three or more types of front parts may be selectively attached to the rear part 2. In this case, as in the above embodiment, it is determined which of the three or more types of front parts is attached to the rear part, and the attachment state (connection state) between each of the three or more types of front parts and the rear part 2 is determined. Also, only one type of front part may be attached to the rear part. In this case, as in the above embodiment, it is determined whether the front part is attached to the rear part, and the attachment state between the front part and the rear part is determined.

[0062] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made in the implementation stage without departing from the gist of the invention. The embodiments may be implemented in combination as appropriate as possible, and in that case, the combined effects can be obtained. Furthermore, the above-mentioned embodiment includes inventions at various stages, and various inventions can be extracted by appropriate combinations of the disclosed constituent elements. [Explanation of symbols]

[0063] 1...multi-stage boom, 2...rear portion, 3A, 3B...front portion, 10...telescopic cylinder, 20...boom control device, 22...cord, 23...connector, 25...controller, 26...boom length measuring unit, Bi, Baj, Bbk...boom components.

Claims

1. A boom control device for controlling the operation of a multi-stage boom that is extendable and contractible in a longitudinal direction and has a front portion detachably attached to a rear portion, comprising: A cord extending from the rear portion and having an extended end connectable to the front portion; a controller that determines that the front portion is attached to the rear portion based on the fact that the extended end of the cord is connected to the front portion, and that determines that the front portion is separated from the rear portion based at least on the fact that the extended end of the cord is not connected to the front portion, and that controls the operation of the multi-stage boom, including extension and contraction of the multi-stage boom, based on a result of the determination of whether the front portion is attached to the rear portion; A boom control device for a construction machine comprising:

2. 2. The boom control device of claim 1, wherein the controller determines that the front portion is separated from the rear portion based on the fact that the extended end of the cord is not connected to the front portion and in addition, the extended end of the cord is connected to the rear portion.

3. Any one of a plurality of different types of front side portions can be selectively attached to the rear side portion, The extended end of the cord is selectively connectable to any one of the plurality of types of front side portions, When the controller determines that the front portion is attached to the rear portion, the controller determines which of the plurality of types of front portions is attached to the rear portion based on the connection destination of the extended end of the cord, and controls the operation of the multi-stage boom, including the extension and contraction of the multi-stage boom, based on the determination result regarding the type of the front portion attached to the rear portion. The boom control device according to claim 1 or 2.

4. the controller is capable of communicating with an appliance attached to the front portion when the extended end of the cord is connected to the front portion, The controller determines whether or not to connect the extended end of the cord based on any one of the presence or absence of a signal transmitted through the cord, the address of a device transmitted through the cord, and a transmission path in the cord of the signal transmitted through the cord. A boom control device according to any one of claims 1 to 3.

5. The multi-stage boom includes a base boom member at the rearmost stage, and a plurality of telescopic boom members that are extendable and contractable in the longitudinal direction relative to the base boom member, the rear section includes the base boom member and one or more of the telescoping boom members, The front section includes one or more of the telescopic boom members, The cord has an extended end connected to the telescopic boom member at the most front stage, and an extended length from the rear portion varies depending on a connection destination of the extended end, the boom control device further includes a boom length measuring unit that measures a length of the multi-stage boom in the longitudinal direction based on the extension length of the cord from the rear side portion to the extension end, the controller determines the connection of the extended ends of the cords based on a measurement result of the length of the multi-stage boom by the boom length measuring unit and a history of extension and contraction of the telescopic boom member of the rear side section and the telescopic boom member of the front side section attached to the rear side section. A boom control device according to any one of claims 1 to 3.

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