JP5453205B2 - Work machine - Google Patents

Description

  The present invention relates to a work machine such as a hydraulic excavator, and more particularly to an improvement in an angle detection device that detects a rotation angle of a rotating member such as a boom, an arm, and an attachment.

  The hydraulic excavator includes a lower traveling body having a crawler belt, an upper revolving body that is turnably mounted on the lower traveling body, a boom that is rotatably coupled to one end of the upper revolving body, and one end that is a boom. And an attachment such as a bucket whose one end is rotatably connected to the arm, and the boom, the arm and the attachment are composed of an upper swing body. In contrast, a multi-joint rotating member that rotates only in the vertical direction is configured.

  2. Description of the Related Art Conventionally, work machines equipped with this type of rotating member are provided with an angle detection device for detecting the rotational angle position of each rotating member (see, for example, Patent Document 1). Patent Document 1 discloses a technique in which a bracket is detachably attached to an arm of a hydraulic excavator, and an arm angle detection device for detecting a rotation angle position of the arm with respect to the boom is attached in the bracket. Of course, if this technology is applied, a boom angle detection device for detecting the rotation angle position of the boom with respect to the upper-part turning body and an attachment angle detection device for detecting the rotation angle position of the attachment with respect to the arm are attached in place. You can also.

Japanese Patent No. 4209349

  By the way, the boom angle detection device, the arm angle detection device, and the attachment angle detection device are based on the rotation angle obtained from the output signal of each detection device and the boom length, arm length, and attachment length known in advance. Since it is provided for calculating the position of the tip of the attachment with respect to the revolving structure, even when a signal corresponding to the rotation angle position of the rotation member is not output from any one of the angle detection devices, smooth operation is possible. It becomes difficult to continue. However, since the excavator is used for excavation of earth and sand, etc., the excavated earth and sand easily collide with the angle detection device and its peripheral part, and in particular, connect the angle detection device and the rotating member. The rotation transmission mechanism is easily broken.

  Each angle detection device provided in the work machine is set to output a voltage signal corresponding to the rotation angle of the rotating member, and the voltage signal exceeds a preset operating range of the rotating member The determination means in the control device that takes in the output signal of the angle detection device and calculates the rotation angle of the rotating member determines that there is an error, and outputs a warning signal from the control device to the notification means such as a buzzer. An alarm is to be notified. Therefore, even when the rotation transmission mechanism connecting the angle detection device and the rotation member is broken, if the detection angle of the angle detection device exceeds the preset operating range of the rotation member for some reason, the notification means It is possible to notify the operator of the occurrence of an abnormality using.

  However, in the angle detection device provided in the conventional work machine, when the rotation transmission mechanism connecting the angle detection device and the rotation member is broken, a voltage signal output from the angle detection device is set in advance. Since no means for forcibly shifting to a value outside the operating range is provided, it is rather normal for the angle detection device to continue outputting a voltage signal when the rotating member is within the operating range. is there. In this case, a constant voltage signal continues to be output from the angle detection device regardless of the rotation of the rotating member, making it difficult to continue the work safely.

  The present invention has been made to solve such a problem of the prior art. The purpose of the present invention is to detect when the rotation transmission mechanism connecting the angle detection device and the rotation member is broken. It is intended to provide a work machine that can immediately notify the user and ensure work safety.

  In order to solve the above-described problems, the present invention provides a plurality of rotating members rotatably connected via a connecting pin, and the other rotating member attached to one of the plurality of rotating members. In a working machine comprising: an angle detection device that outputs a signal corresponding to the rotation angle of the first rotation member; and a rotation transmission mechanism that transmits a rotation motion of the other rotation member with respect to the one rotation member to a rotation portion of the angle detection device. And an urging means for urging the rotating portion of the angle detecting device in a specific direction, wherein the urging means releases the mechanical connection between the rotating portion of the angle detecting device and the rotation transmitting mechanism. The rotating unit is rotated to a predetermined position outside a preset operating range.

  According to this configuration, when the rotation transmission mechanism that connects the angle detection device and the rotation member is broken and the mechanical connection between the rotation portion of the angle detection device and the rotation transmission mechanism is released, the elastic force of the urging means is used. Since the rotating part of the angle detection device is rotationally driven to a predetermined position outside the preset operating range, the output signal of the angle detection device automatically becomes a value outside the operating range of the rotating member by the rotation transmission mechanism. Therefore, the determination means in the control device can immediately determine that the output signal of the angle detection device is an error, can notify the operator of an alarm, and can prevent an illegal operation of the work machine. .

  In the work machine having the above-described configuration, the torsion spring mounted around the rotating unit is used as the urging unit, and both ends of the torsion spring are fixed to the rotating unit at one end. It is engaged with a bracket that covers the angle detection device.

  According to such a configuration, the torsional force of the torsion spring can be applied between the lever that is the rotating body and the bracket that is the fixed body, so the rod that transmits the rotation of the rotating member to the lever, and the connecting pin that connects the rod and the lever Can be rotated to a predetermined position outside the preset operating range by the torsional force of the torsion spring.

  According to the present invention, in the work machine having the above-described configuration, a tension spring is used as the biasing means, and both ends of the tension spring are related to a lever having one end fixed to the rotating portion and a bracket that covers the angle detection device. It is characterized by being combined.

  Even with such a configuration, the tension force of the tension spring can be applied between the lever that is the rotating body and the bracket that is the fixed body. Therefore, the rod that transmits the rotation of the rotating member to the lever, and the connecting pin that connects the rod and the lever Can be rotated by a tensile force of a tension spring to a predetermined position outside a preset operating range.

  According to the present invention, in the work machine having the above-described configuration, a tension spring is used as the biasing unit, and the rotational movement of the other rotation member with respect to the one rotation member is performed at both ends of the tension spring via the lever. It is characterized by engaging with a rod that transmits to the rotating part and a bracket that covers the angle detection device.

  According to this configuration, the tension force of the tension spring is applied between the rod that transmits the rotational motion of the other rotating member relative to the one rotating member to the rotating portion of the angle detecting device via the lever and the bracket that is the fixed body. Therefore, when the tip of the rod is broken by the impact of earth and sand, etc., the rotating part of the angle detection device is driven to rotate to a predetermined position outside the preset operating range by the tensile force of the tension spring. can do.

  Since the present invention includes the urging means for urging the rotating portion of the angle detection device in a specific direction, the elasticity of the urging means is removed when the rotation transmission mechanism connecting the angle detection device and the rotation member is broken. The rotation part of the angle detection device is automatically rotated to a predetermined position outside the preset operating range by the force, and the output signal of the angle detection device becomes a value corresponding thereto. Immediately, the output signal of the angle detection device can be determined as an error, an alarm can be notified to the worker, and unauthorized operation of the work machine can be prevented.

1 is a side view of a hydraulic excavator that is an example of a work machine according to an embodiment. It is a side view which shows the connection state of the arm which concerns on embodiment, and an attachment. It is a side view which shows the angle detection apparatus provided with the torsion spring as a biasing means, and its peripheral part. It is sectional drawing which shows the angle detection apparatus provided with the torsion spring as a biasing means, and its peripheral part. It is a side view which shows operation | movement of the angle detection apparatus provided with the torsion spring as a biasing means. It is a side view which shows the angle detection apparatus provided with the tension spring as a biasing means, and its peripheral part. It is sectional drawing which shows the angle detection apparatus provided with the tension spring as a biasing means, and its peripheral part. It is a side view which shows the other example of the angle detection apparatus provided with the tension spring as a biasing means, and its peripheral part.

  First, the working machine according to the present invention will be described taking a hydraulic excavator as an example.

  As shown in FIG. 1, the hydraulic excavator according to the embodiment includes a 1a lower traveling body 1 having a crawler belt, an upper revolving body 2 that is turnably mounted on the lower traveling body 1, and an upper revolving body 2. A provided driver's seat 3, a boom 4 whose one end is rotatably connected to the upper swing body 2, a boom cylinder 5 that rotationally drives the boom 4 in the vertical direction, and one end that rotates relative to the boom 4. An arm 6 that is pin-coupled so as to be able to rotate, an arm cylinder 7 that rotationally drives the arm 6 in the up-and-down direction, and one end that is rotatably pin-coupled to the arm 6 and a working link 25 between the arm 6 And the attachment cylinder 9 that rotationally drives the attachment 8 in the vertical direction via the work link 25. Further, the required portions of the boom 4 and the arm 6 include three angle detection devices that detect the rotation angle of the boom 4 with respect to the upper swing body 2, the rotation angle of the arm 6 with respect to the boom 4, and the rotation angle of the attachment 8 with respect to the arm 6. 10 is provided.

  As shown in FIGS. 2 to 5, the rotation angle of the attachment 8 with respect to the arm 6 is such that one end is connected to one of the link members constituting the work link 25 and the other end is an angle detection device. It is detected by connecting to the tip of the lever 13 fixed to the ten rotation shafts 12. That is, when the attachment 8 is rotated upward as shown by a solid line in FIG. 2 from the state where the attachment 8 is rotated downward with respect to the arm 6 as shown by a broken line in FIG. In conjunction with the movement, one end of the rod 14 is pushed rightward in the figure, and the other end of the rod 14 rotates the lever 13 in the direction of the arrow 15 as shown in FIG. On the contrary, when the attachment 8 is rotated downward from above, the other end of the rod 14 rotates the lever 13 in the direction opposite to the arrow 15. The angle detection device 10 includes a stator portion 10a fixed to a bracket 11 and a rotation shaft 12 rotatably attached to the stator portion 10a. A voltage signal corresponding to the rotation angle of the rotation shaft 12 with respect to the stator portion 10a. Is output. Therefore, a voltage signal corresponding to the rotation angle of the attachment 8 with respect to the arm 6 is output from the angle detection device 10.

  The operating range of the rotary shaft 12 is set so as not to exceed the movable range of the rotary shaft 12 capable of outputting a voltage signal even when the attachment 8 is driven to the maximum limit of a predetermined normal working range. If the attachment 8 is driven to a predetermined maximum limit or more, a voltage signal corresponding to the rotation angle of the rotary shaft 12 at that time is output from the angle detection device 12. At this time, a determination means (not shown) in the control device that takes in the output signal of the angle detection device 10 and calculates the rotation angle of the attachment 8 determines that there is an error, and as shown in FIG. An alarm signal is output to the notification means 20 to notify the worker of the alarm.

  As shown in FIGS. 3 and 4, a torsion spring 16 is mounted around the rotary shaft 12, and both ends of the torsion spring 16 are respectively provided with spring hooking protrusions 17 formed on the bracket 11 and lever 13. Engage with the left side. Thereby, the angle detecting device 10 is given an elastic force that constantly urges the rotating shaft 12 in the clockwise direction. Accordingly, when the rod 14, the connecting portion of the rod 14 and the lever 13, and the portion of the lever 13 ahead of the portion where the torsion spring 16 is engaged are broken due to collision with earth or sand, the rotary shaft 12 is connected to the torsion spring 16. It automatically rotates to the right movable end by the elastic force and outputs a voltage signal corresponding to it. As a result, an alarm is issued from the notification means 20, so that the operator can immediately know that an abnormality has occurred.

  As described above, the working machine of this example is provided with the torsion spring 16 around the rotary shaft 12, and both ends of the torsion spring 16 are respectively provided on the spring hooking protrusion 17 formed on the bracket 11 and the left side of the lever 13. Since the engagement has occurred, the rod 14, the connecting portion of the rod 14 and the lever 13, and the portion ahead of the portion where the torsion spring 16 of the lever 13 is engaged breaks due to collision with earth and sand, etc. The elastic force of the spring 16 automatically rotates to the right movable end, and an alarm can be immediately issued from the notification means 20 so that the operator can immediately leave the occurrence of an abnormality. Unauthorized operation of the work machine against this can be prevented.

  In the above-described embodiment, the torsion spring 16 is used to apply an elastic force to the rotating shaft 12 of the angle detection device 10. However, as shown in FIGS. 6 and 7, the spring hook formed on the lever 13 and the bracket 11 is used. The same effect can be obtained by engaging both ends of the tension spring 21 with the protrusion 22.

  Furthermore, as shown in FIG. 8, it can also be set as the structure which engages the both ends of the tension | pulling spring 21 with the spring hooking protrusion 22 formed in the rod 14 and the bracket 11. FIG. In this case, when the portion of the rod 14 ahead of the portion to which the tension spring 21 is engaged is broken due to collision with earth or sand, the rotary shaft 12 is moved to the right movable end by the elastic force of the torsion spring 16. It can be automatically rotated and an alarm can be immediately issued from the notification means 20, and the occurrence of an abnormality can be left unattended to the worker, thereby preventing an illegal operation of the work machine against the operator's will. be able to.

  In each of the above embodiments, the rotation detection device that detects the rotation angle of the attachment 8 with respect to the arm 6 has been described as an example, but the rotation detection device that detects the rotation angle of the boom 4 with respect to the upper swing body 2 and the boom 4 The same can be applied to a rotation detection device that detects the rotation angle of the arm 6.

  The present invention can be used for angle detection of a working machine such as a hydraulic excavator.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 1a Crawler belt 2 Upper revolving body 3 Driver's seat 4 Boom 5 Boom cylinder 6 Arm 7 Arm cylinder 8 Attachment 9 Attachment cylinder 10 Angle detection apparatus 10a Stator part 11 Bracket 12 Rotating shaft 13 Lever 14 Rod 15 Arrow 16 Torsion spring 17 Spring hooking projection 20 Notifying means 21 Tension spring 22 Spring hanging projection 25 Working link

Claims (4)

Angle detection that outputs a signal corresponding to the rotation angle of the other rotating member with respect to the one rotating member, and a plurality of rotating members that are rotatably connected via a connecting pin. In a work machine comprising an apparatus and a rotation transmission mechanism that transmits a rotational movement of the other rotation member relative to the one rotation member to a rotation unit of the angle detection device,
The urging means for urging the rotating part of the angle detecting device in a specific direction is provided, and the urging means is released from mechanical connection between the rotating part of the angle detecting device and the rotation transmitting mechanism. The rotating machine is driven to rotate to a predetermined position outside a preset operating range.   A torsion spring mounted around the rotating part is used as the biasing means, and both ends of the torsion spring are engaged with a lever whose one end is fixed to the rotating part and a bracket that covers the angle detecting device. The work machine according to claim 1.   The tension spring is used as the biasing means, and both ends of the tension spring are engaged with a lever whose one end is fixed to the rotating portion and a bracket that covers the angle detection device. Working machine.   A rod that uses a tension spring as the biasing means, and transmits the rotational motion of the other rotating member relative to the one rotating member to the rotating portion via the lever at both ends of the tension spring, and the angle detection device The work machine according to any one of claims 2 and 3, wherein the work machine is engaged with a bracket that covers the cover.

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