JP4998486B2 - Swivel work machine - Google Patents

Description

  The present invention relates to a turning work machine in which an upper turning body can turn with respect to a lower traveling body, and more particularly to a turning angle detection structure thereof.

  2. Description of the Related Art Conventionally, there is known a swing type work machine that includes an upper swing body that can swing with respect to a lower travel body and that detects a swing angle of the upper swing body with respect to the lower travel body.

  For example, in Patent Document 1, a detection object is provided on the lower traveling body, a deceleration sensor and a stop sensor that detect the detection object and generate a deceleration or stop signal are provided on the upper swing body, and based on the deceleration signal from the deceleration sensor. Then, the deceleration command is output to the turning drive unit, and the stop command is output to the turning drive unit based on the stop signal from the stop sensor, thereby stopping the upper turning body at a preset target position.

JP 2007-191283 A (particularly FIG. 13)

  By the way, conventionally, in order to prevent overload, calculation of the stability of a swing type work machine has been performed. Stability refers to the stability of a hydraulic excavator (swing-type work machine) against overturning. The ratio is the ratio of the moment that falls from the falling fulcrum to the excavator body and the moment that falls from the falling fulcrum to the attachment. (Stability = Stable Moment / Falling Moment). It can be said that the greater the stability, the more stable.

  Specifically, in the case of the hydraulic excavator 1 shown in FIG. 2 and FIG. 3, in the case of the hydraulic excavator 1 shown in FIG. 2 and FIG. 3, a stable moment acting from the overturning fulcrum Y to the hydraulic excavator body side The distance L2) and the overturning moment acting from the overturning fulcrum Y to the attachment side (the mass W1 of the attachment × the distance L1 from the overturning fulcrum Y to the center of gravity G2 of the attachment) is the stability S (S = W2 × L2 / W1 × L1).

  As shown in FIG. 2, in a vertically long posture where the longitudinal direction of the crawler 3 and the attachment 15 are within a predetermined turning angle range, the intersection of the perpendicular line dropped from the center of the sprocket 3 ′ of the crawler 3 and the ground is the fall fulcrum Y It becomes. On the other hand, as shown in FIG. 3, when the attachment 15 turns to the side and is in a horizontally long posture larger than a predetermined turning angle, the intersection of the perpendicular line dropped from the center of the crawler 3 on the attachment 15 side and the ground is the fall fulcrum Y ′. become. For this reason, the L2 in the vertically long posture is larger than the L2 ′ in the horizontally long posture (L1> L1 ′), and when the stability S is the same, the maximum working radius R1 in the vertically long posture is in the horizontally long posture. It becomes larger than the maximum working radius R2 (R1> R2).

  However, in the conventional turning type work machine, the deceleration sensor and the stop sensor, which are proximity sensors, are attached to the sensor mounting bracket extending from the lower surface of the upper turning body so as to face the inside in the radial direction of the turning bearing outer ring. Further, the detected body extends from the outer periphery of the inner ring to the outer side in the radial direction and further outward than the outer ring. As described above, since the proximity sensor and the detected object are provided outside the outer ring, for example, when the swing type work machine is a building demolition machine, the proximity sensor and the detected object extend from the wall being disassembled. There was a problem that it was easily damaged by such factors.

  For this reason, a demolition machine or the like cannot be provided with a turning angle detection device, and the attachment is not stable within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body. Since the calculation was performed, when the attachment is within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body and in a vertically long state with high allowable stability, the attachment can be further extended farther. In addition, the alarm means sounded the alarm. For this reason, the ability of the swivel work machine could not be fully utilized.

  Moreover, in the conventional turning type work machine, the deceleration sensor and the stop sensor, which are proximity sensors, are attached to a proximity sensor mounting bracket that extends downward and is welded or integrally provided on the lower surface of the upper swing body. Further, the detected object is fastened to a tapped block welded to the swivel bearing. For this reason, in order to add and attach these proximity sensors and detected bodies to an existing swing type work machine, it is necessary to weld the lower surface of the upper swing body and the outer periphery of the inner ring. This welding operation is troublesome, and there is a demand for avoiding welding to the outer periphery of the inner ring of the bearing, which is a particularly important structural component.

  The present invention has been made in view of such a point, and an object of the present invention is to arrange the turning angle detection device so as to be compact and difficult to damage, and to be easily attached or detached. .

  In order to achieve the above object, according to the present invention, the proximity sensor and the detection plate can be arranged so as not to protrude outward from the outer ring.

Specifically, in the first invention, the lower traveling body whose traveling direction coincides with the longitudinal direction;
An upper revolving unit mounted on the lower traveling unit through a swivel bearing about a vertical axis;
An attachment connected to the front side of the upper swing body so as to be raised and lowered;
An inner ring provided on the slewing bearing and connected to the lower traveling body in a rotationally integrated manner;
An outer ring provided on the slewing bearing, connected to the upper slewing body in a rotationally integrated manner, and having an outer diameter larger than the outer diameter of the inner ring;
A turning angle detection device for detecting a turning angle of the upper turning body with respect to the lower traveling body;
A swivel work machine equipped with

And the turning angle detection device is
A proximity sensor provided on the upper swing body side;
A detection plate provided on the lower traveling body side, formed in an arc shape centered on the vertical axis and detected by the proximity sensor;
The proximity sensor is configured to be detachably attached to the lower surface of the outer ring below the outer ring.

According to said structure, since the proximity sensor is provided in the lower surface of an outer ring | wheel so that attachment or detachment is possible, it is easy to replace | exchange and can also attach to the existing turning type work machine. Furthermore, it is possible to provide the proximity sensor so that it does not protrude outward from the outer periphery of the outer ring, and even in a building demolition machine or the like, the proximity sensor is prevented from being damaged by a reinforcing bar or the like extending from the wall during demolition. The

In the second invention, in the first invention,
The outer ring is integrally connected to the upper swing body with an upper swing bolt.
The proximity sensor is attached to the outer ring by the upper turning bolt.

  According to the above configuration, the proximity sensor can be detached by detaching the upper turning bolt, so that replacement repair and additional attachment to an existing turning work machine are easy. Moreover, since the existing upper turning bolt is used, an increase in the number of parts can be suppressed.

In the third invention, in the second invention,
The proximity sensor is detachably attached to an upper fastening plate that is fastened to the outer ring together with the upper turning bolt.

  In other words, because the upper slewing bolt is large in size, the torque required for attachment / detachment is large, the workability is poor, and it is an important part that requires strict torque management in particular, so the risk of quality deterioration due to frequent attachment / detachment However, according to the above configuration, since the proximity sensor is detachably attached to the upper fastening plate, even if the proximity sensor is damaged, the proximity sensor is removed without removing the upper fastening plate. Sensor replacement is easy. For this reason, it is easy to replace and repair or to add to an existing swivel work machine. Further, when the proximity sensor is attached to the outer ring by bolt connection, a bolt having a size smaller than that of the upper turning bolt can be used. Therefore, the workability of removing and attaching the bolt is good, and torque management at the time of fastening the bolt is easy.

In the fourth invention, in the third invention,
The proximity sensor is attached to a sensor mounting bracket attached to the upper joint plate,
The sensor mounting bracket is provided with a sensor cover that covers the proximity sensor from the outside in the radial direction of the swing bearing.

  According to the above configuration, since the proximity sensor is covered with the sensor cover from the outside in the radial direction of the slewing bearing, damage to the proximity sensor is further effectively prevented. Moreover, since the sensor cover is attached to the sensor mounting bracket, it can be easily attached and replaced.

In the fifth invention, in the fourth invention,
A side plate of the sensor cover extends to the vicinity of the outer periphery of the inner ring, and a contact prevention notch through which the detected plate can enter and exit is formed on the side plate.

  According to the above configuration, the proximity sensor that is easily damaged can be more effectively protected by covering the proximity sensor with the side plate of the sensor cover as wide as possible. In addition, it is possible to prevent the obstacle such as dust placed on the upper surface of the detection plate from contacting the proximity sensor, and to remove the obstacle.

In the sixth invention, in the fourth or fifth invention,
The sensor cover includes an extension that covers a harness extending from the upper swing body to the proximity sensor from the radially outer side of the outer ring.

  According to the above configuration, the proximity sensor passing through the outer side of the outer ring is covered with the extension part of the sensor cover so that the proximity sensor is more unlikely to break down.

In a seventh invention, in the second to sixth inventions,
The side of the proximity sensor and the plate to be detected detected by the proximity sensor is disposed directly below the outer ring and outside the inner ring.

  According to said structure, since a proximity sensor and a to-be-detected plate do not protrude from the outer periphery of an outer ring | wheel, it becomes further difficult to receive a damage.

In an eighth invention, in any one of the second to seventh inventions,
The proximity sensor is disposed at the left and right center of the upper swing body.

  According to the above configuration, since the proximity sensor is arranged at the center of the left and right of the upper swing body, the detected plate can be disposed on the front side and the rear side of the lower travel body. As compared with the case where it is provided on the crawler, it is easy to attach and detach the detection plate and away from the crawler. In addition, the proximity sensor or the like can be easily attached and detached, and the damage status is obvious, so inspection is easy. Furthermore, it is easy to handle the harness that reaches the proximity sensor.

In a ninth invention, in any one of the second to eighth inventions,
The outer ring has a greasing hole on the left and right center front of the upper swing body,
The proximity sensor is disposed directly below the greasing hole,
The sensor cover includes an exposure hole corresponding to the greasing hole.

  That is, the greasing hole of the outer ring is often arranged in front of the left and right center of the upper swing body considering the ease of maintenance. Similarly, the turning angle detection device is also arranged on the front side, which is easy to detach and attach, the damage status is obvious and easy to check. Even in such a case, according to the above configuration, the swivel bearing can be lubricated from the exposure hole of the sensor cover, and at the same time, the swivel angle detector can be inspected. The sensor cover also has a protective function for preventing the greasing hole from being damaged by contact of debris or the like with the greasing hole.

In the tenth invention, the lower traveling body whose traveling direction coincides with the longitudinal direction;
An upper revolving unit mounted on the lower traveling unit through a swivel bearing about a vertical axis;
An attachment connected to the front side of the upper swing body so as to be raised and lowered;
An inner ring provided on the slewing bearing and connected to the lower traveling body in a rotationally integrated manner;
An outer ring provided on the slewing bearing, connected to the upper slewing body in a rotationally integrated manner, and having an outer diameter larger than the outer diameter of the inner ring;
A turning angle detection device for detecting a turning angle of the upper turning body with respect to the lower traveling body;
For swivel work machines equipped with
The turning angle detection device is
A proximity sensor provided on the upper swing body side;
A detection plate provided on the lower traveling body side, formed in an arc shape centered on the vertical axis and detected by the proximity sensor;
The proximity sensor is detachably attached to the outer ring below the outer ring,
The inner ring is integrally connected to the lower traveling body by a lower swivel bolt.
The detected plate is attached to the inner ring by the lower turning bolt.

According to said structure, since the proximity sensor is provided in the outer ring so that attachment or detachment is possible, it is easy to replace | exchange and can also be attached to the existing turning type work machine. Furthermore, it is possible to provide the proximity sensor so that it does not protrude outward from the outer periphery of the outer ring, and even in a building demolition machine or the like, the proximity sensor is prevented from being damaged by a reinforcing bar or the like extending from the wall during demolition. The Further, since the plate to be detected can be detached by detaching the lower turning bolt, addition or replacement by modification is easy. Moreover, since the existing lower turning bolt is used, an increase in the number of parts can be suppressed.

In an eleventh aspect, in the tenth aspect,
The detected plate is detachably attached to a lower joint fastening plate fastened to the inner ring together with the lower turning bolt.

  That is, because the lower swivel bolt is large, the torque required for attachment / detachment is large, the workability is poor, and it is an important part that requires particularly strict torque management, so the risk of quality deterioration due to frequent attachment / detachment However, according to the above configuration, the plate to be detected is detachably attached to the lower tightening plate. Exchange is easy. For this reason, it is easy to replace and repair the plate to be detected or to add it to an existing swivel work machine. In addition, when the detected plate is attached to the inner ring by bolt connection, a bolt smaller in size than the lower turning bolt can be used, so that the work of removing and attaching the bolt is good and the torque management at the time of bolt fastening is also easy. .

In a twelfth invention, in any one of the first to eleventh inventions,
Based on the detection result of the turning angle detection device, the stability of the attachment when the orientation of the attachment is within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body, and the vertically long shape that does not fall within the predetermined angle. A stability switching device that switches between the horizontal stability and the allowable stability lower than the stability;
Alarm means for sounding an alarm when the work radius of the attachment increases and the allowable stability calculated based on the longitudinal stability or the lateral stability switched by the stability switching device is exceeded.

  That is, conventionally, the turning angle detection device is easily damaged, and it is troublesome to mount and replace the turning angle detection device. Therefore, the attachment is not detected within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body without particularly detecting the turning angle. Since the stability was calculated with low stability in the horizontal state, when the attachment is within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body and is in the vertically long state with high allowable stability, Even if the attachment could be extended further, the alarm means sounded the alarm. For this reason, the ability of the swivel work machine could not be fully utilized. However, according to the above configuration, since the turning angle detection device that is not easily damaged and easy to replace is provided, the turning angle can be detected reliably, and the turning angle detection device can be easily added even with existing machines. From this detection result, the stability switching device switches to the vertical stability in the vertical state with high stability and to the horizontal stability in the horizontal state with low stability. Is utilized to the maximum.

In a thirteenth invention, in any one of the first to twelfth inventions,
A hydraulic excavator having a crusher attached to the tip of the attachment.

  In other words, in a hydraulic excavator with a crusher attached to the tip of the attachment, the proximity sensor and the detection plate are easily damaged during the dismantling work, but according to the above configuration, the proximity sensor and the detection plate protrude from the outer ring. Since the amount is small, damage due to reinforcing bars or the like extending from the wall being dismantled is prevented, and even if it is damaged, replacement is easy.

As described above, according to the present invention, the proximity sensor of the turning angle detection device is provided below the outer ring so as to be detachable from the lower surface of the outer ring, so that the turning angle detection device is compact and hardly damaged. And can be arranged so that it can be easily attached or removed.

  According to the second aspect, the proximity sensor is attached to the outer ring with the upper turning bolt, so that the proximity sensor can be easily replaced and repaired or added to the existing turning work machine while the number of parts is reduced. it can.

  According to the third invention, since the proximity sensor can be detachably fastened to the upper joint fastening plate, the proximity sensor can be replaced without loosening the upper turning bolt. Is extremely easy.

  According to the fourth aspect of the invention, the proximity sensor is covered from the outside in the radial direction of the slewing bearing by the sensor cover provided on the outer ring. Therefore, damage to the proximity sensor during work can be more effectively prevented.

  According to the fifth aspect of the present invention, the contact cover is provided on the side plate of the sensor cover extending to the vicinity of the outer periphery of the inner ring so that the detected plate can be moved in and out, thereby further effectively preventing contact with the detected plate. It is possible to prevent damage to the proximity sensor.

  According to the sixth aspect of the present invention, the harness extending from the upper swing body to the proximity sensor is protected from the radially outer side of the outer ring by expanding the sensor cover, so that the proximity sensor harness is effectively damaged. Since it can prevent, a proximity sensor becomes difficult to break down further.

  According to the seventh aspect, the proximity sensor and the detection plate of the turning angle detection device are provided outside the inner ring and directly below the outer ring, so that the turning angle detection device is arranged so as to be compact and difficult to damage. It can be made highly durable.

  According to the eighth aspect, by disposing the proximity sensor at the center of the left and right of the upper swing body, it is possible to effectively prevent the proximity sensor from being damaged by the reinforcing bar or the like entangled with the crawler away from the crawler. In addition, it is possible to easily check and replace the turning angle detection device on the front.

  According to the ninth aspect, since the proximity sensor is disposed directly below the grease hole of the outer ring at the center of the left and right of the upper swing body, the inspection and replacement of the proximity sensor and the like can be easily performed together with the lubrication of the outer ring. Can do.

According to the tenth aspect of the present invention, the proximity sensor of the turning angle detection device is provided detachably with respect to the outer ring below the outer ring, thereby making the turning angle detection device compact and difficult to damage, and easily. It can be arranged so that it can be attached or removed. Further, by attaching the detected plate to the inner ring with the lower turning bolt, it is possible to easily add or replace the detected plate by remodeling while suppressing an increase in the number of parts.

  According to the eleventh aspect of the invention, the detected plate can be replaced without removing the lower tightening plate by detachably attaching the detected plate to the lower ring tightening plate fastened together with the lower turning bolt to the inner ring. Therefore, it is possible to perform addition or replacement repair by modifying the detected plate more easily without using a torque wrench.

  According to the twelfth aspect, from the detection result of the turning angle detection device, the stability switching device appropriately switches to portrait stability in a vertically long state with high stability and to landscape stability in a horizontally long state with low stability. As a result, the ability of the swivel work machine can be utilized to the maximum by the swivel angle detection device that is less likely to fail and can be easily replaced.

  According to the thirteenth aspect of the invention, by preventing damage caused by reinforcing bars or the like extending from the wall being dismantled, a highly durable hydraulic excavator that is unlikely to fail can be obtained.

It is the II sectional view taken on the line of FIG. 6 showing an enlarged swivel angle detection device for a hydraulic excavator according to an embodiment of the present invention. It is a side view which shows the operation | work with the maximum radius in a vertically long attitude | position. It is a side view which shows the operation | work with the maximum radius in a landscape orientation. It is a bottom view which shows a turning angle detection apparatus and its periphery. It is a bottom view which expands and shows a turning angle detection apparatus and its periphery. It is a front view which expands and shows a turning angle detection apparatus and its periphery. It is a perspective view which expands and shows a turning angle detection apparatus and its periphery. It is a block diagram which shows the structure of a turning angle detection apparatus, a stability switching apparatus, and an alarm buzzer. It is a top view which shows a turning angle and the maximum working radius of a hydraulic shovel.

1 Excavator (Swivel work machine)
DESCRIPTION OF SYMBOLS 2 Lower traveling body 5 Rotating bearing 6 Outer ring 6a Greasing hole 7 Inner ring 10 Upper turning body 11 Lower turning bolt 12 Upper turning bolt 14 Crusher 15 Attachment 20 Turning angle detection device 21 Proximity sensor 22 Detected plate 23 Upper fastening plate 24 Sensor mounting bracket 25 Harness 26 Cover mounting member 27 Sensor cover 27a Contact prevention notch 27b Exposed hole 28 Extension part 30 Lower tightening plate 40 Stability switching device 41 Alarm buzzer (alarm means)

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

  1 to 4 show a hydraulic excavator 1 as a swivel working machine according to an embodiment of the present invention, and this hydraulic excavator 1 includes a lower traveling body 2 whose traveling direction coincides with the longitudinal direction. Specifically, the lower traveling body 2 includes a pair of left and right longitudinal crawlers 3 and a car body 4 that connects the left and right crawlers 3. A slewing bearing 5 is mounted on the pedestal 4 a at the upper end of the car body 4. The slewing bearing 5 includes an outer ring 6, an inner ring 7, and a ball 8 accommodated between the outer ring 6 and the inner ring 7.

  As shown in FIGS. 5 to 7, the upper swing body 10 is mounted on the car body 4 so as to be rotatable about the vertical axis X (vertical axis) via the swing bearing 5. That is, the inner ring 7 is fastened integrally with the base 4a of the car body 4 with a proper torque by a plurality of lower turning bolts 11 arranged at a predetermined distance in the circumferential direction. The outer ring 6 having an outer diameter larger than the outer diameter of the inner ring 7 is rotated with respect to the lower surface of the upper swing body 10 with an appropriate torque by a plurality of upper swing bolts 12 arranged at a predetermined distance in the circumferential direction. It is fastened together.

  And the long attachment 15 with which the crusher 14 (only shown in FIG.2 and FIG.3) was mounted | worn with the boom foot 13 of the upper turning body 10 was connected so that raising / lowering was possible. Although this embodiment has illustrated the hydraulic excavator 1 with which the long boom provided with the crusher 14 was supported, it is not limited to this.

  As shown in FIGS. 1 and 4 to 7, the excavator 1 includes a turning angle detection device 20 that detects a turning angle of the upper turning body 10 with respect to the lower traveling body 2. The turning angle detection device 20 is provided, for example, on the front side of the car body 4, the proximity sensor 21 provided on the upper turning body 10 side, and the detection plates provided on the front and back sides on the lower traveling body 2 side. 22. The proximity sensor 21 is provided outside the inner ring 7 and directly below the outer ring 6, and is attached to the outer ring 6 via an upper tightening plate 23 that is fastened to the lower surface of the outer ring 6 by the upper turning bolt 12. As shown in FIGS. 5 and 6 in an enlarged manner, the upper joint fastening plate 23 is made of, for example, an arc-shaped steel plate having a pair of bolt insertion holes (not shown) through which the upper turning bolt 12 is inserted. Screw holes (not shown) are formed between the bolt insertion holes. A sensor mounting bracket 24 is detachably fastened to the screw hole by a mounting bolt 23a. A plurality of screw holes may be provided. The sensor mounting bracket 24 is bent at a front end at a right angle to either the left, right, front or rear (in this embodiment, rightward when viewed from the front as shown in FIG. 6), and a sensor mounting hole (not shown) provided at the front end. ) Is provided with a proximity sensor 21.

  The proximity sensor 21 is composed of, for example, an inductive non-contact sensor, and is configured to transmit an ON signal when the metal approaches a predetermined range, and to transmit an OFF signal when the metal is outside the predetermined range. Yes. The detection signal of the proximity sensor 21 is transmitted via the harness 25 to a fall alarm device 50 (shown only in FIG. 8) provided in the upper swing body 10 (for example, the driver's seat).

  A cover mounting member 26 having an L shape in a side view is fastened to the upper joint plate 23. Two pairs of bolt holes are formed in the cover mounting member 26, and a U-shaped notch 26a is formed between the bolt holes. The U-shaped notch 26 a is formed corresponding to the greasing hole 6 a for feeding the grease formed on the front side of the outer ring 6. A grease nipple 6b is attached to the greasing hole 6a. When this greasing hole 6a is not provided, the U-shaped notch 26a is not necessary. The sensor cover 27 is attached by inserting bolts 26c into the two pairs of bolt holes of the cover attaching member 26 and fastening them with nuts 26d. The sensor cover 27 covers the proximity sensor 21 and the sensor mounting bracket 24 from the radially outer side of the slewing bearing 5 (the front side of the excavator 1). In FIG. 7, the sensor cover 27 is indicated by a two-dot chain line for easy viewing. The sensor cover 27 has a rectangular shape when viewed from the front, and the left and right side plates extend to the vicinity of the outer periphery of the inner ring 7. These left and right side plates are respectively formed with contact prevention cutouts 27a that are long in the front-rear direction in which the plate 22 to be detected can enter and exit. The upper end of the sensor cover 27 extends to the vicinity of the bottom surface of the upper swing body 10. Moreover, since the steel plates 4b arranged above and below the car body 4 are also covered from below, it is very difficult for objects to hit the proximity sensor 21. A circular exposed hole 27b is formed at a position corresponding to the U-shaped notch 26a in the sensor cover 27, and a round pipe 27c having an inner diameter slightly larger than the inner diameter of the exposed hole 27b on the back side of the peripheral edge of the exposed hole 27b. Are welded. The round pipe 27c makes it easy to supply grease to the grease nipple 6b and prevents the sensor cover 27 from bending inward when the sensor cover 27 is pushed.

  Further, the sensor cover 27 includes an extension portion 28 that covers the harness 25 that extends from the upper swing body 10 to the proximity sensor 21 from the radially outer side of the outer ring 6. The extension portion 28 is formed in an L shape in a side view so that the harness 25 covers a portion along the upper swing body 10 from the proximity sensor 21. The extended portion 28 effectively protects the easily damaged harness 25. The extension 28 is not necessarily provided.

  On the other hand, as shown in FIG. 5, the detected plate 22 is attached to the lower surface of the inner ring 7 via a lower tightening plate 30 that is fastened together with the lower turning bolt 11. The lower joint fastening plate 30 is made of, for example, a short arc-shaped steel plate having a pair of bolt insertion holes (not shown) through which the lower turning bolt 11 is inserted, and fastens the detection plate 22 in addition to the pair of bolt insertion holes. A pair of screw holes (not shown) are formed at intervals in the circumferential direction. The excavator 1 has a total of four lower tightening plates 30. In the present embodiment, for example, as shown in FIG. 9, a predetermined turning angle α is detected within a range of 25 ° to the left and right with respect to the longitudinal direction of the lower traveling body 2. Therefore, two lower tightening plates 30 are fastened to the front side of the inner ring 7 and two lower fastening plates 30 to the rear side.

  As shown in FIG. 5, the plate 22 to be detected is formed in a circular arc band centered on the vertical axis X, and is made of a steel plate so as to be detected when approaching within a predetermined range of the proximity sensor 21. On the inner side in the radial direction of the plate 22 to be detected, four projecting portions 22a for fastening the plate to be detected 31 are attached to the lower joint fastening plate 30, and the plate 31 to be detected is attached to the projecting portion 22a. A bolt hole (not shown) to be inserted is formed. It should be noted that the lower turning bolt 11 can be tightened by the presence of a notch recess in the vicinity of the protrusion 22a. On the other hand, the lower joint plate 30 is provided with a spacer 32 made of a round pipe by welding or the like. The spacer 32 may be integrally attached to the detection plate 22 by welding or the like, or may be a separate member that is not fixed to either. The spacer 32 prevents the detected plate 22 from contacting the head of the other lower turning bolt 11 by maintaining the distance from the lower surface of the inner ring 7 and also maintains the level of the detected plate 22. Generation of detection errors of the proximity sensor 21 is prevented. In this way, the detected plate 22 can be attached to and detached from the front and the back of the inner ring 7 so that the proximity sensor 21 reacts when the attachment 15 is directed in any of the front and rear directions with respect to the lower traveling body 2. It is concluded to.

  As described above, since the turning angle detection device 20 is provided using the existing upper turning bolt 12 and the lower turning bolt 11, an increase in the number of parts is suppressed.

  As shown in FIG. 8, the hydraulic excavator 1 includes a stability switching device 40, and the stability switching device 40 has the attachment 15 in the longitudinal direction of the lower traveling body 2 based on the detection result of the turning angle detection device 20. On the other hand, it is configured to switch between the vertical stability when it falls within the turning angle α and the horizontal stability that does not fall within the turning angle α and has an allowable stability lower than the vertical stability. For example, the stability switching device 40 is built in the fall alarm device 50.

  Further, the excavator 1 includes an alarm buzzer 41 that sounds an alarm when the attachment 15 exceeds the allowable stability based on the longitudinal stability or the lateral stability switched by the stability switching device 40. The alarm buzzer 41 is also built in the fall alarm device 50.

-Operation-
Next, the operation of the hydraulic excavator 1 according to the present embodiment will be described.

  As shown in FIG. 9, when the upper turning body 10 is located within the predetermined turning angle α with respect to the lower traveling body 2, the stability switching device 40 switches to the longitudinal stability and performs the stability calculation. In this case, the attachment 15 can be operated within the range indicated by the alternate long and short dash line in FIG. 2 (from the minimum working radius R0 to the maximum working radius R1). If it is out of this range, the alarm buzzer 41 will sound.

  On the other hand, when the upper turning body 10 is not located within the predetermined turning angle α with respect to the lower traveling body 2, the stability switching device 40 switches to the horizontal stability and calculates the stability. In this case, the attachment 15 can be operated within the range indicated by the two-dot chain line in FIG. 3 (from the minimum working radius R0 to the maximum working radius R2, R2 <R1). If it is out of this range, the alarm buzzer 41 will sound.

  By the way, conventionally, the turning angle is not particularly detected, and the stability calculation is performed with low stability in a horizontally long state where the attachment 15 does not fall within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body 2. For this reason, when the attachment 15 is in a vertically long state in which the attachment 15 is within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body 2, the attachment buzzer 41 can be extended further, Was ringing. For this reason, the capacity of the hydraulic excavator 1 has not been fully utilized.

  However, in the present embodiment, the stability switching device 40 switches to the vertical stability with high stability in the vertical state and to the horizontal stability with low stability in the horizontal state, so that the turning angle is as shown in FIG. Within the range of the front and rear 2α, the maximum working radius R1 is large, and in other ranges, the maximum working radius R2 is equivalent to the conventional working radius that has not been switched. For this reason, the capability of the hydraulic excavator 1 can be utilized to the maximum extent.

  During the dismantling work of the hydraulic excavator 1, the proximity sensor 21 and the plate 22 to be detected are easily damaged by reinforcing bars or the like extending from the wall being disassembled.

  However, in the present embodiment, the proximity sensor 21 and the detection plate 22 are provided so as not to protrude outward from the outer periphery of the outer ring 6, so that the proximity sensor 21 and the detection plate 22 are reinforced by reinforcing bars extending from the wall being disassembled. Damage is prevented. This is also reliable because the proximity sensor 21 and the plate 22 to be detected are covered from the outside in the radial direction of the slewing bearing 5 by the sensor cover 27 extending to the vicinity of the outer surface of the inner ring 7.

  Further, by providing the contact prevention cutout 27a on the side plate of the sensor cover 27, the obstacle such as dust placed on the upper surface of the detection plate 22 is prevented from coming into contact with the proximity sensor 21, and the obstacle is removed. be able to. Further, the sensor cover 27 can prevent the greasing hole 6a from being damaged by contact of debris or the like with the greasing hole 6a.

  Furthermore, since the harness 25 of the proximity sensor 21 that passes through the outside of the outer ring 6 and is easily damaged is covered with the extension 28 of the sensor cover 27, the proximity sensor 21 is more unlikely to break down.

  Further, by disposing the proximity sensor 21 at the center of the left and right of the upper-part turning body 10, it is possible to effectively prevent the proximity sensor 21 from being separated from the crawler 3 and damaged by a rebar entangled with the crawler 3.

  Even if the proximity sensor 21 fails or the harness 25 is cut, the proximity sensor 21 transmits an ON signal when the metal approaches the predetermined range, and an OFF signal when the metal is outside the predetermined range. Since the ON signal is not transmitted from the proximity sensor 21, the excavator 1 is operated within the range of the lateral stability on the safe side. For this reason, an accident does not occur due to insufficient stability during operation.

-Inspection and replacement of turning angle detector 20-
When inspecting and exchanging the turning angle detection device 20, the proximity sensor 21 is arranged at the center of the left and right of the upper revolving body 10, so that it can be easily inspected and exchanged because it is in front of the machine body.

  Further, since the proximity sensor 21 is disposed directly below the grease ring 6a of the outer ring at the center of the left and right of the upper swing body 10, the proximity sensor 21 and the like can be easily inspected and replaced together with the lubrication of the outer ring 6. it can.

  When the sensor cover 27 is damaged, since the sensor cover 27 is detachably fastened to the upper fastening plate 23, the sensor cover 27 can be replaced without removing the upper fastening plate 23.

  Further, when the proximity sensor 21 fails, the sensor mounting bracket 24 is detachably attached to the upper fastening plate 23, so that the replacement can be easily performed without removing the upper fastening plate 23. Done. For this reason, since the upper turning bolt 12 is large in size, the torque required for attaching / detaching becomes large, the workability is poor, and it is an important part requiring particularly strict torque management. However, since it is not necessary to remove the upper turning bolt 12, a torque wrench or the like is not required for removal for torque management when replacing the proximity sensor 21.

  Similarly, when the detected plate 22 is damaged, the detected plate 22 is detachably attached to the lower tightening plate 30, so that the replacement can be easily performed without removing the lower tightening plate 30. To be done. For this reason, since the lower turning bolt 11 is large in size, the torque required for attaching / detaching becomes large, the workability is poor, and it is an important part that requires particularly strict torque management, so the quality deteriorates due to frequent attachment / detachment. However, since it is not necessary to remove the lower slewing bolt 11, a torque wrench or the like is not required for removal for torque management when replacing the detection plate 22.

  Note that the proximity sensor 21 is attached to the upper swing body 10 via the upper fastening plate 23, and the proximity sensor 21 is attached to the lower traveling body 2 via the lower fastening plate 30, so that the existing excavator 1 On the other hand, the proximity sensor 21 and the detection plate 22 can be additionally attached without welding to the lower surface of the upper swing body 10 and the outer periphery of the inner ring 7.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the proximity sensor 21 is provided outside the inner ring 7 and directly below the outer ring 6, but the side detected by the proximity sensor 21 of the proximity sensor 21 and the detection plate 22 in plan view is the outer circumference of the outer ring 6. It may protrude slightly. However, the proximity sensor 21 and the detection plate 22 at the same height as the outer ring 6 are not included at least in a side view.

  In the above embodiment, the proximity sensor 21 is an inductive non-contact sensor. However, the proximity sensor 21 is not limited to this, and may be a capacitance type or magnetic type that is not a contact type sensor.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

Claims (13)

A lower traveling body whose traveling direction coincides with the longitudinal direction;
An upper revolving unit mounted on the lower traveling unit through a swivel bearing about a vertical axis;
An attachment connected to the front side of the upper swing body so as to be raised and lowered;
An inner ring provided on the slewing bearing and connected to the lower traveling body in a rotationally integrated manner;
An outer ring provided on the slewing bearing, connected to the upper slewing body in a rotationally integrated manner, and having an outer diameter larger than the outer diameter of the inner ring;
A turning angle detection device for detecting a turning angle of the upper turning body with respect to the lower traveling body;
A swivel working machine with
The turning angle detection device is
A proximity sensor provided on the upper swing body side;
A detection plate provided on the lower traveling body side, formed in an arc shape centered on the vertical axis and detected by the proximity sensor;
The swivel work machine characterized in that the proximity sensor is detachably attached to the lower surface of the outer ring below the outer ring. The swivel work machine according to claim 1,
The outer ring is integrally connected to the upper swing body with an upper swing bolt.
The swivel work machine, wherein the proximity sensor is attached to the outer ring by the upper swivel bolt. The swivel work machine according to claim 2,
The swivel work machine is characterized in that the proximity sensor is detachably attached to an upper tightening plate fastened together with the upper swivel bolt to the outer ring. The swivel work machine according to claim 3,
The proximity sensor is attached to a sensor mounting bracket attached to the upper joint plate,
A swing type work machine, wherein the sensor mounting bracket is provided with a sensor cover that covers the proximity sensor from the radially outer side of the swing bearing. The swivel work machine according to claim 4,
A swing type work machine, wherein a side plate of the sensor cover extends to the vicinity of an outer periphery of the inner ring, and a contact prevention notch through which the detected plate can enter and exit is formed on the side plate. In the turning work machine according to claim 4 or 5,
The above-mentioned sensor cover is provided with the extension which covers the harness extended from the above-mentioned upper revolving body to the above-mentioned proximity sensor from the radial outside of the above-mentioned outer ring. The swivel work machine according to any one of claims 2 to 6,
A turning type work machine, wherein the proximity sensor and the side of the plate to be detected that are detected by the proximity sensor are arranged directly below the outer ring and outside the inner ring. The swivel work machine according to any one of claims 2 to 7,
The swivel work machine characterized in that the proximity sensor is arranged at the left and right center of the upper swing body. The swivel work machine according to any one of claims 2 to 8,
The outer ring has a greasing hole on the left and right center front of the upper swing body,
The proximity sensor is disposed directly below the greasing hole,
The above-mentioned sensor cover is provided with an exposure hole corresponding to the above-mentioned greasing hole, A turning type working machine characterized by things. A lower traveling body whose traveling direction coincides with the longitudinal direction;
An upper revolving unit mounted on the lower traveling unit through a swivel bearing about a vertical axis;
An attachment connected to the front side of the upper swing body so as to be raised and lowered;
An inner ring provided on the slewing bearing and connected to the lower traveling body in a rotationally integrated manner;
An outer ring provided on the slewing bearing, connected to the upper slewing body in a rotationally integrated manner, and having an outer diameter larger than the outer diameter of the inner ring;
A turning angle detection device for detecting a turning angle of the upper turning body with respect to the lower traveling body;
A swivel working machine with
The turning angle detection device is
A proximity sensor provided on the upper swing body side;
A detection plate provided on the lower traveling body side, formed in an arc shape centered on the vertical axis and detected by the proximity sensor;
The proximity sensor is detachably attached to the outer ring below the outer ring,
The inner ring is integrally connected to the lower traveling body by a lower swivel bolt.
The swing type work machine, wherein the detected plate is attached to the inner ring by the lower swing bolt. The swivel work machine according to claim 10,
The swing type work machine, wherein the detected plate is detachably attached to a lower tightening plate fastened together with the lower swing bolt to the inner ring. The turning work machine according to any one of claims 1 to 11,
Based on the detection result of the turning angle detection device, the stability of the attachment when the orientation of the attachment is within a predetermined turning angle with respect to the longitudinal direction of the lower traveling body, and the vertically long shape that does not fall within the predetermined angle. A stability switching device that switches between the horizontal stability and the allowable stability lower than the stability;
Alarm means for sounding an alarm when the work radius of the attachment increases and the allowable stability calculated based on the longitudinal stability or the lateral stability switched by the stability switching device is exceeded. Rotating work machine characterized by The swivel work machine according to any one of claims 1 to 12,
A rotary work machine, wherein the excavator is a hydraulic excavator having a crusher attached to the tip of the attachment.

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