JP2008214997A - Revolving angle detection apparatus of revolving work machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a revolving angle detecting device which can easily detect a revolving angle. <P>SOLUTION: According to the structure of the revolving angle detecting device, a reflector plate 21 which is set such that a distance between a distance sensor 11 and the reflector plate itself is uniquely fixed according to a revolving angle θ, is arranged, and the revolving angle θ is calculated based on the distance between the distance sensor 11 and the reflector plate 21, measured by the distance sensor 11. Thus, arrangement of sensors for calculating the revolving angle θ, such as the distance sensor 11 and the reflector plate 21, is facilitated, and therefore detection of the revolving angle θ is facilitated, which leads to reduction of costs necessary for detecting the revolving angle θ. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turning angle detection device used in a turning work machine including a traveling body and a turning body that turns with respect to the traveling body.

  In a construction machine having a traveling body and a work machine body that is turnably supported by the traveling body, the overturning moment and the stability moment change according to the turning angle of the working machine body with respect to the traveling body. Therefore, there is known a construction machine that detects the turning angle of the work implement main body and presents the positional relationship between the traveling body and the work implement main body to an operator (see Patent Document 1).

JP-A-6-128987

  In a conventional construction machine, a sensor for detecting a turning angle is attached using a swivel joint for supplying pressure oil from a hydraulic pump of a work machine body to a traveling body. However, since there are many hydraulic pipes around the swivel joint, it is difficult to arrange the sensor with high accuracy, and much time is required for installation.

(1) A turning angle detecting device for a turning work machine according to the invention of claim 1 is a turning angle detecting device for a turning work machine comprising a traveling body and a turning body that turns with respect to the traveling body. A projection unit for projecting the measurement signal toward and a reception unit for receiving the reflection signal reflected from the reflection surface, detecting means for detecting the distance from the reflection surface, and reflecting the measurement signal output from the projection unit Based on the distance between the reflecting member having a reflecting surface having a shape determined so that the distance between the projecting unit and the reflecting unit varies according to the turning angle of the turning body, and the reflecting member detected by the detecting means, the turning body And a calculating means for calculating the turning angle.
(2) According to a second aspect of the present invention, in the turning angle detecting device for a turning work machine according to the first aspect, the reflecting member is determined such that a distance between the reflecting member and the projection unit varies according to the turning angle. It is characterized by being a spiral member.
(3) The invention according to claim 3 is the turning angle detecting device for the turning work machine according to claim 1 or 2, wherein the detecting means is different from the first detecting means and the first detecting means. A second detecting means provided at the place, and the calculating means calculates the turning angle based on the distance from the reflecting member detected by either the first detecting means or the second detecting means; It is characterized by that.
(4) The invention of claim 4 is the turning angle detecting device for the turning work machine according to any one of claims 1 to 3, wherein the reflecting member is disposed on the traveling body, and the detecting means is turned. It is arranged on the body.
(5) The invention of claim 5 is the turning angle detecting device for the turning work machine according to any one of claims 1 to 4, further comprising a dustproof cover for the detecting means and the reflecting member. And

  According to the present invention, the turning angle can be easily detected.

--- First embodiment ---
With reference to FIGS. 1-4, 1st Embodiment of the turning angle detection apparatus of the turning type work machine by this invention is described. FIG. 1 is a left side view of a hydraulic excavator that is an example of a construction machine equipped with a turning angle detection device according to the present invention. On the endless track type lower traveling body 1, the upper revolving body 2 is mounted so as to be freely turnable via a turning wheel 10. The upper revolving structure 2 includes a revolving frame 3 that forms a structure, a cab 4 on the left side of the front of the revolving frame 3, and a work device 5 for performing excavation work and the like at the front center of the revolving frame 3. On the rear side of the frame 3, a counterweight 6 is installed for balancing with the work device 5. A building cover 7 defining a machine room is installed between the cab 4 and the counterweight 6 on the revolving frame 3.

  FIG. 2 is a diagram illustrating a configuration of the turning angle detection device. The turning angle detection device includes a distance sensor 11, a reflecting plate 21, and a turning angle calculation control unit 31. The distance sensor 11 is a non-contact type distance sensor using laser light, and receives a reflection signal reflected from the reflection part and a projection part (emitting part) that projects a measurement signal (laser light) toward the reflection surface. This is a sensor that has a receiving unit (incident unit) that detects the distance to the reflecting surface. The distance sensor 11 is attached to the upper revolving body 2 side such as the lower part of the upper revolving body 2 and the outer periphery of an outer race (not shown) of the revolving wheel 10 and detects the distance from the reflector 21 described later.

  The reflecting plate 21 is centered on the center of rotation of the turning wheel 10 such as a portion for fixing the turning wheel 10 to the lower traveling body 1 and the outer periphery of the inner race 10a of the turning wheel 10 as shown in FIG. It is a spiral plate member of about one turn attached to the side. FIG. 2 is a diagram schematically showing the periphery of the turning wheel 10, and the outer race of the turning wheel 10 is not shown. The reflecting plate 21 is disposed such that the position in the height direction is uniquely determined according to the angular phase around the rotation center of the swivel wheel 10. That is, the reflecting plate 21 is a spiral member that is determined so that the distance from the distance sensor 11 varies according to the turning angle of the upper turning body 2. The distance sensor 11 is arranged so that the distance sensor 11 can measure the distance to the reflecting plate 21 by moving the distance sensor 11 directly above the reflecting plate 21 when the upper swing body 2 turns.

  FIG. 3 is a view schematically showing the inner race 10a and the reflecting plate 21, FIG. 3 (a) is a plan view, and FIG. 3 (b) is a side view seen from the left side of the excavator. In FIG. 3, O represents the rotation center of the turning wheel 10, and Z represents the rotation axis of the turning wheel 10. The reflection plate 21 has one end (upper end) 21a and the other end (lower end) 21b having different height positions. In addition, when the reflection plate 21 is viewed from above, the reflection plate 21 in the vicinity of the upper end 21a and the vicinity of the lower end 21b are not provided so that a gap is not generated between the upper end 21a and the lower end 21b when the reflection plate 21 is viewed from above. The reflector 21 overlaps. That is, the reflecting plate 21 is formed so that the laser light emitted from the distance sensor 11 always hits the upper surface of the reflecting plate 21.

  The reflecting plate 21 is attached to the lower traveling body 1 side by using a fastening member such as a bolt by cutting a spiral plate member that is cut along a radial direction of the spiral into a plurality of parts, thereby forming a single reflecting plate 21. It is fixed. A dustproof cover 40 is provided around the distance sensor 11 and the reflecting plate 21 to protect the distance sensor 11 and the reflecting plate 21 from dust (FIG. 2).

  The dust cover 40 is constituted by, for example, cylindrical portions 41 and 42. The cylindrical portion 41 is fixed to the lower traveling body 1 side. The cylindrical portion 42 has an inner diameter slightly larger than the outer diameter of the cylindrical portion 41 so as to surround the outer periphery of the cylindrical portion 41, is fixed to the upper swing body 2 side, and overlaps the cylindrical portion 41 along the axial direction. By configuring the dustproof cover 40 in this way, a gap is provided between the outer peripheral surface of the cylindrical portion 41 and the inner peripheral surface of the cylindrical portion 42, and the turning of the upper swing body 2 with respect to the lower traveling body 1 is obstructed. In addition, entry of dust and the like from the outside to the inner peripheral side of the cylindrical portion 41 can be suppressed. In addition, each cylindrical part 41 and 42 can be divided | segmented into multiple in radial direction, and can be easily removed from the lower traveling body 1 or the upper revolving body 2 by disassembling in a divided part. This facilitates the emission of laser light from the distance sensor 11 and the removal of dust and the like adhering to the incident portion and the surface of the reflecting plate 21, and the maintainability is good.

  The turning angle calculation control unit 31 determines the turning angle of the upper turning body 2 relative to the lower traveling body 1 (hereinafter simply referred to as the turning angle θ) based on the distance between the distance sensor 11 and the reflector 21 measured by the distance sensor 11. calculate. Specifically, the turning angle calculation control unit 31 calculates the turning angle θ as follows. When the upper swing body 2 turns with respect to the lower travel body 1, the distance between the distance sensor 11 and the lower travel body 1 does not change, but the angular phase around the rotation center of the swivel wheel 10 (that is, the turning angle θ). Accordingly, the distance between the distance sensor 11 and the reflector 21 changes uniquely.

  The turning angle calculation control unit 31 stores the relationship between the distance between the distance sensor 11 and the reflection plate 21 measured by the distance sensor 11 and the turning angle θ as a table (corresponding table) in a storage unit (not shown). The turning angle calculation control unit 31 calculates the turning angle θ by reading the turning angle θ corresponding to the distance measured by the distance sensor 11 from the correspondence table.

  The correspondence table fixes the distance sensor 11 to the upper swing body 2 side, fixes the reflecting plate 21 to an attachment location such as the outer periphery of the inner race 10a, and then actually turns the upper swing body 2 with respect to the lower traveling body 1. Thus, it is created by acquiring the correspondence between the turning angle θ and the measurement distance of the distance sensor 11. For example, by using a highly accurate position measuring means called RTK-GPS (Real Time Kinematic GPS) and a surveying instrument such as a total station, the turning angle θ can be recorded simultaneously with the measurement distance of the distance sensor 11. .

  In addition, if it can fix to the attachment location, maintaining the inclination angle of the reflecting plate 21 with high precision, it calculates using the relational expression of turning angle (theta) and the measurement distance of the distance sensor 11 irrespective of a corresponding table. May be used to calculate the turning angle θ. As described above, when the turning angle θ is calculated using the correspondence table, the accuracy of the inclination angle of the reflecting plate 21 after being fixed depends on the angle phase around the rotation center of the turning wheel 10. It is sufficient that the position in the height direction is uniquely determined, and some variation in the tilt angle is allowed.

  When the turning angle calculation control unit 31 calculates the turning angle θ as described above, the turning angle calculation control unit 31 outputs the calculated turning angle θ to the moment calculation control unit 32. The moment calculation control unit 32 calculates a stable moment that prevents the hydraulic excavator from overturning, and a tipping moment that operates so as to cause the hydraulic excavator to fall over, and prevents the excavator from overturning based on the calculated moments. It is a device for operating an alarm device (not shown). The moment calculation control unit 32 uses the turning angle θ calculated by the turning angle calculation control unit 31 to calculate a stability moment and a tipping moment. The calculation method of the stable moment and the overturning moment in the moment calculation control unit 32 and the operation of operating an alarm device (not shown) based on the calculated moments are well known, and the description thereof is omitted.

  In the turning angle detection device configured as described above, as described above, the turning angle calculation control unit 31 reads the distance between the distance sensor 11 and the reflection plate 21 measured by the distance sensor 11 and corresponds to the read distance. The turning angle θ is calculated by reading the turning angle θ from the correspondence table. When the upper swing body 2 turns with respect to the lower traveling body 1, the distance between the distance sensor 11 and the reflection plate 21 changes according to the turning angle θ. The turning angle calculation control unit 31 uses the distance measured by the distance sensor 11. Is read as needed to calculate the turning angle θ. The value of the turning angle θ calculated by the turning angle calculation control unit 31 is output to the moment calculation control unit 32 as described above, and is used to calculate the stability moment and overturning moment of the hydraulic excavator.

--- Flow chart ---
FIG. 4 is a flowchart of processing for calculating the turning angle θ. This process is performed by a program executed by the turning angle calculation control unit 31. When an engine key switch (not shown) is turned on, this program is started.

  In step S1, the distance between the distance sensor 11 and the reflector 21 measured by the distance sensor 11 is read, and the process proceeds to step S3. In step S3, the turning angle θ corresponding to the measurement distance of the distance sensor 11 read in step S1 is read from the correspondence table, and the process proceeds to step S5. In step S5, the value of the turning angle θ read in step S3 is output to the moment calculation control unit 32 and the process returns.

The turning angle detection device of the first embodiment described above has the following operational effects.
(1) A reflecting plate 21 is provided so that the distance from the distance sensor 11 is uniquely determined according to the turning angle θ, and the distance between the distance sensor 11 and the reflecting plate 21 measured by the distance sensor 11 is set. Based on this, the turning angle θ is calculated. As a result, the sensors for calculating the turning angle θ such as the distance sensor 11 and the reflecting plate 21 can be easily arranged, the detection of the turning angle θ is facilitated, and the cost for detecting the turning angle θ is facilitated. Can be reduced. Moreover, since it comprised so that the turning angle (theta) might be calculated based on the distance of the distance sensor 11 and the reflecting plate 21 obtained by the reflecting plate 21 without a movable part, and the distance sensor 11 attached to the upper revolving body 2, There are few failures and high reliability. Furthermore, since it is easy to install, it can be easily retrofitted to existing construction machines at low cost.

(2) The distance sensor 11 can be disposed on the lower traveling body 1 side, and the reflector 21 can be disposed on the upper revolving body 2 side. In this case, the distance sensor 11 and the turning angle calculation control unit 31 It is necessary to provide a slip ring or the like between them to absorb the rotation of the lower traveling body 1 and the upper swing body 2. On the other hand, in the turning angle detection apparatus described above, since the distance sensor 11 is provided on the upper turning body 2 side, the connection of the distance sensor 11 is facilitated, the reliability is high, and the installation cost can be reduced.

(3) Since the reflection plate 21 is configured to be attached to the outer periphery of the inner race 10a of the turning wheel 10, the installation work becomes easy and the installation cost can be reduced.

(4) Since the reflection plate 21 is fixed by attaching the plurality of divided spiral plate members to the lower traveling body 1 side using fastening members such as bolts, , Maintenance and replacement such as adjustment of position / tilt angle, dust removal, etc. are facilitated.

(5) Since the dustproof cover 40 is provided, it is possible to suppress the emission of the laser light of the distance sensor 11 and the incident site, and the adhesion of dust and the like to the surface of the reflecting plate 21, so the maintenance frequency of the distance sensor 11 and the reflecting plate 21 This can reduce running costs.

--- Second Embodiment ---
With reference to FIGS. 5-7, 2nd Embodiment of the turning angle detection apparatus of the turning type work machine by this invention is described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first embodiment. The present embodiment is different from the first embodiment in that two distance sensors are provided and the distance sensor used for calculating the turning angle θ is appropriately switched and used.

  FIG. 5 is a diagram illustrating a configuration of the turning angle detection device according to the second embodiment. In the turning angle detection device of the present embodiment, a distance sensor 12 is provided in addition to the distance sensor 11. The distance sensor 12 is a non-contact type distance sensor that uses the same laser light as the distance sensor 11. Like the distance sensor 11, the lower part of the upper swing body 2, the outer periphery of the outer race (not shown) of the swivel wheel 10, etc. It is attached to the upper swing body 2 side and detects the distance from the reflecting plate 21.

  In the present embodiment, the distance sensor 12 is disposed at a position that is substantially symmetric with respect to the position where the distance sensor 11 is disposed, for example, with the rotation center of the turning wheel 10 as the center. However, when the upper-part turning body 2 is turned, it can be moved just above the reflecting plate 21 in the same manner as the distance sensor 11 to measure the distance from the reflecting plate 21, and a switching area to be described later can be set at the same time as the distance sensor 11. The position is not limited to the position described above as long as the distance is not measured.

  FIG. 6 is a diagram schematically showing the inner race 10a and the reflecting plate 21, FIG. 6 (a) is a plan view, and FIG. 6 (b) is a side view seen from the left side of the excavator. When the distance sensors 11 and 12 pass in the vicinity of the upper end 21a as the upper swing body 2 turns, the laser light emitted from the distance sensors 11 and 12 is scattered by the influence of the shape of the upper end 21a. Thus, accurate ranging may be difficult. Therefore, in the turning angle detection device of the present embodiment, when the distance sensor 11 is in a position for measuring the switching region, the turning angle is based on the distance from the reflector 21 measured by the distance sensor 12. θ is calculated.

  Here, the switching region is a region on the reflecting plate 21 centered on “the angular phase of the upper end 21a centering on the rotation center O”, and the regions 22a and 22b hatched in FIG. Point to. That is, the switching region refers to the regions 22a and 22b in the vicinity of the upper end 21a and the lower end 21b in the upper surface of the reflecting plate 21. As shown in FIG. 6B, the switching area is from the distance measurement reference height of the distance sensors 11 and 12 (that is, the height position where the distance measured by the distance sensors 11 and 12 is assumed to be 0). It is defined as a region where the distance is L1 or less, or a region where the distance is L2 or more.

  Therefore, the turning angle calculation control unit 31 determines that the distance sensor 11 is in a position to measure the switching area when the distance measured by the distance sensor 11 is L1 or less or L2 or more, The turning angle θ is calculated based on the distance from the reflecting plate 21 measured by the distance sensor 12.

  The turning angle calculation control unit 31 stores the relationship between the distance between the distance sensor 12 and the reflecting plate 21 measured by the distance sensor 12 and the turning angle θ in a storage unit (not shown) as a table (sub sensor correspondence table). ing. When it is determined that the distance sensor 11 is not in a position to measure the switching area, the turning angle calculation control unit 31 sets the turning angle θ corresponding to the distance measured by the distance sensor 11 to the correspondence table ( The turning angle θ is calculated by reading from the main sensor correspondence table. Further, when it is determined that the distance sensor 11 is in a position to measure the switching area, the turning angle calculation control unit 31 uses the turning angle θ corresponding to the distance measured by the distance sensor 12 as a sub-range. The turning angle θ is calculated by reading from the sensor correspondence table.

--- Flow chart ---
FIG. 7 is a flowchart of the calculation process of the turning angle θ. This process is performed by a program executed by the turning angle calculation control unit 31. When an engine key switch (not shown) is turned on, this program is started.

  In step S11, the distance to the reflecting plate 21 measured by the distance sensors 11 and 12 is read, and the process proceeds to step S12. In step S12, it is determined whether the distance measured by the distance sensor 11 is equal to or less than the distance L1 described above or equal to or greater than the distance L2 described above.

  If an affirmative determination is made in step S12, the process proceeds to step S13, the turning angle θ corresponding to the measurement distance of the distance sensor 12 read in step S11 is read from the sub sensor correspondence table, and the process proceeds to step S15. Further, if a negative determination is made in step S12, the process proceeds to step S23, the turning angle θ corresponding to the measurement distance of the distance sensor 11 read in step S11 is read from the main sensor correspondence table, and the process proceeds to step S15.

  In step S15, the value of the turning angle θ read in step S13 or step S23 is output to the moment calculation control unit 32, and the process returns.

The turning angle detection device of the second embodiment described above has the following operational effects in addition to the operational effects of the first embodiment.
(1) When the two distance sensors 11 and 12 are arranged at different positions and the distance sensor 11 is at a position for measuring the switching area, the distance sensor 11 is arranged at a position away from the distance sensor 11. The turning angle θ is calculated based on the distance from the reflecting plate 21 measured by the distance sensor 12. As a result, even if the distance sensor 11 is affected by the shape of the upper end 21a and there is a risk that accurate distance measurement may be difficult, the distance sensor 12 can accurately measure the distance without being affected by the shape of the upper end 21a. The calculation of the turning angle θ is highly reliable.

---- Modified example ---
(1) In the second embodiment described above, it is determined whether or not the distance sensor 11 is in a position to measure the switching area based on the distance measured by the distance sensor 11. The invention is not limited to this. For example, the distance range measured by the distance sensor 12 when the distance sensor 11 is in a position for measuring the switching area is stored in advance, and the distance measured by the distance sensor 12 is stored. When the distance is within the range, it may be determined that the distance sensor 11 is in a position to measure the switching area. Further, another sensor such as a proximity sensor may be provided separately, and it may be determined whether or not the distance sensor 11 is in a position to measure the switching area by the sensor.

(2) In the second embodiment described above, the turning angle θ is calculated based on the distance measured by the distance sensor 12 only when the distance sensor 11 is in a position to measure the switching area. Yes. That is, in the second embodiment described above, the distance sensor 11 is positioned as the main sensor for distance measurement, and the distance sensor 12 is used as a secondary when the distance sensor 11 is at a position where the distance sensor 11 measures the switching area. However, the present invention is not limited to this. For example, after the distance sensor 11 reaches the upper part of the switching area by turning the upper swing body 2, the distance measured by the distance sensor 12 is maintained until the distance sensor 12 reaches the upper part of the switching area even after leaving the upper part of the switching area. Based on this, the turning angle θ may be calculated. In other words, the sensors 11 and 12 may be positioned equally.

  As a result, even if one distance sensor may be affected by the shape of the upper end 21a and accurate distance measurement may be difficult, the other distance sensor can accurately measure the distance without being affected by the shape of the upper end 21a. Therefore, the calculation of the turning angle θ is highly reliable.

(3) In the above description, the reflector 21 is disposed such that the position in the height direction is uniquely determined according to the angular phase around the rotation center of the swivel wheel 10. It is not limited to this. For example, as shown in the schematic plan view shown in FIG. 8, the reflector 121 is disposed so that the radial position is uniquely determined according to the angular phase around the rotation center O of the turning wheel 10. The distance sensor 11 is attached to the upper swing body 2 side so as to irradiate the laser beam toward the rotation center O, and the distance from the side surface of the reflector 121 is measured. And based on the distance with the side surface of the reflecting plate 121 measured with the distance sensor 11, you may make it calculate turning angle (theta) from the table memorize | stored beforehand.

  In this way, the reflecting plate reflects the laser beam output from the distance sensor 11 and has a reflecting surface having a shape determined so that the distance from the distance sensor 11 varies according to the turning angle θ. Should just be formed.

(4) In the above description, the distance sensors 11 and 12 are non-contact distance sensors using laser light, but the present invention is not limited to this. For example, an ultrasonic distance sensor using ultrasonic waves may be used. However, in the ultrasonic distance sensor, since the directivity of the emitted ultrasonic wave is low as compared with the laser distance sensor, it is difficult to measure the distance near the upper end 21a. Therefore, a laser-type distance sensor with high directivity of the emitted laser light is used, or, for example, another distance sensor located at a position away from the switching region as in the above-described modification (1), or separately installed It is desirable to use a sensor so that distance measurement is not necessary in the vicinity of the switching area.

(5) In the above description, a hydraulic excavator is cited as an example of a construction machine. However, an upper portion of the lower traveling body such as a wheel-type hydraulic excavator, a wheel loader, a hydraulic crane, and other work machines is used. The present invention can also be applied to various types of work machines configured so that the revolving structure revolves. Further, the present invention is applied to a turning device including a base-side structure and a turning body that turns with respect to the base-side structure, such as a crane (for example, a jib crane) that is fixedly installed and used. May be.
(6) The above-described embodiments and modifications may be combined.

  In the above-described embodiment and its modifications, for example, the detecting means corresponds to the distance sensors 11 and 12, and the reflecting member corresponds to the reflecting plates 21 and 121, respectively. The calculation means is realized by a turning angle calculation control unit 31 and a control program executed by the turning angle calculation control unit 31. The above description is merely an example, and when interpreting the invention, there is no limitation or restriction on the correspondence between the items described in the above embodiment and the items described in the claims.

It is a left side view of a hydraulic excavator equipped with a turning angle detection device. It is a figure which shows the structure of the turning angle detection apparatus of 1st Embodiment. It is a figure which shows the inner race 10a and the reflecting plate 21 typically. It is a flowchart of the calculation process of turning angle (theta). It is a figure which shows the structure of the turning angle detection apparatus of 2nd Embodiment. It is a figure which shows the inner race 10a and the reflecting plate 21 typically. It is a flowchart of the calculation process of turning angle (theta). It is a figure which shows a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper turning body 10 Turning wheel 11, 12 Distance sensor 21, 121 Reflecting plate 31 Turning angle calculation control unit 40 Dust-proof cover

Claims (5)

In a turning angle detection device for a turning work machine comprising a running body and a turning body that turns with respect to the running body,
A detection unit for projecting a measurement signal toward the reflection surface, and a reception unit for receiving a reflection signal reflected from the reflection surface, and detecting a distance from the reflection surface;
A reflecting member that reflects the measurement signal output from the projecting unit and has the reflecting surface in a shape determined so that the distance between the projecting unit varies according to the turning angle of the revolving unit;
A turning angle detecting device for a turning work machine, comprising: a calculating means for calculating a turning angle of the turning body based on a distance from the reflecting member detected by the detecting means. In the turning angle detection device of the turning work machine according to claim 1,
The turning angle detecting device for a turning work machine, wherein the reflecting member is a spiral member determined such that a distance between the reflecting member and the projection unit varies according to the turning angle. In the turning angle detection device for a turning work machine according to claim 1 or 2,
The detection means includes a first detection means and a second detection means provided at a place different from the first detection means,
The calculating means calculates the turning angle based on a distance from the reflecting member detected by any one of the first detecting means and the second detecting means. Swivel angle detector. In the turning angle detection device of the turning work machine according to any one of claims 1 to 3,
The reflecting member is disposed on the traveling body,
The swivel angle detection device for a swivel work machine, wherein the detection means is disposed on the swivel body. In the turning angle detection device for a turning work machine according to any one of claims 1 to 4,
A swivel angle detecting device for a swivel work machine, further comprising a dustproof cover for the detecting means and the reflecting member.

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