JP6620512B2 - Work machine - Google Patents

Description

  The present invention relates to a work machine having an angle sensor device, and more particularly to a mounting structure for the angle sensor.

  2. Description of the Related Art Conventionally, there has been known an apparatus in which an angle sensor is provided on an attachment of a work machine such as a hydraulic excavator or a crusher to detect a rotation angle of the attachment.

  For example, as in Patent Document 1, a shaft, a housing that supports the shaft with a bearing portion, and a circuit board on which a plurality of magnetic sensors are mounted, a permanent magnet is fixed to one end of the shaft, The end is exposed to the outside of the housing, and the housing includes a permanent magnet and a plurality of magnetic sensors, and has a housing lid having a flat portion facing the one end of the shaft in the axial direction. There is known a rotation angle detection sensor fixed to a flat portion.

JP 2011-58870 A

  In the above-mentioned Patent Document 1, it is assumed that the shaft and the housing to which the magnetic sensor is attached are fixed, and it is assumed that there is no deviation in the circumferential direction due to axial magnetic sensor displacement or shaft play. ing.

  However, in a work machine such as a hydraulic excavator, the axial dimension between the flange portion of the connection pin that connects the rotating member and the detent pin that prevents the connection pin from rotating is the link through which the connection pin is inserted. In order to be able to absorb the dimensional tolerances of the bearing (bush), spacer, and other parts, the movement restriction in the axial direction of the connection pin adjusted by the flange portion and the locking pin is designed with a margin. In addition, there is a problem that the angle sensor and the marker are not provided at accurate positions due to backlash due to aging, wear, etc., and the detection accuracy is lowered.

  The present invention has been made in view of this point, and an object of the present invention is to keep the positional relationship between the angle sensor and the marker following the axial displacement of the connection pin.

  In order to achieve the above object, according to the present invention, an elastic member is provided that biases a detection member mounting bracket to which an angle sensor or a marker is fixed to one end side of the connection pin.

Specifically, in the first invention, the first member, the second member coupled to the first member so as to be rotatable around the connection pin, and the second member to the first member. A working machine including an angle sensor device for detecting a rotation angle;
The connection pin is provided on the first member so as to rotate integrally with the second member;
The angle sensor device is
A marker provided on one end of the connection pin and a mounting bracket having a pin contact surface arranged with a gap from one end of the connection pin;
An angle sensor that is provided at one end of the connection pin and the other of the mounting bracket at a predetermined distance at a position facing the marker, and detects a rotation angle of the marker;
The detection member mounting bracket is attached to the first member so as to be movable in the axial direction of the connection pin, and is urged toward one end of the connection pin by an elastic member.

  That is, the connection pin is designed so that there is a gap in the axial direction to some extent due to dimensional tolerances and the like, and rattling occurs due to deterioration over time. However, according to the above configuration, the elastic member presses the detection member mounting bracket attached with the angle sensor or the marker to one end side of the connection pin, so that the detection member mounting bracket is in the axial direction of the connection pin with respect to the first member. It moves and this margin and backlash are absorbed. As a result, the interval between the marker and the angle sensor is maintained at a predetermined interval, so that an accurate rotation angle can be detected.

In the second invention, in the first invention,
The detection member mounting bracket is covered with a gap by a protective member fixed to the first member,
The elastic member is provided in the gap between the inner surface of the protection member and the detection member mounting bracket.

  According to the above configuration, the elastic member provided in the gap between the detection member mounting bracket and the inner surface of the protective member causes the dimensional error between the rotation preventing member of the connection pin and the flange portion of the connection pin by pressing the connection pin. Effectively absorbed.

In the third invention, in the second invention,
The detection member mounting bracket is provided so as not to rotate with respect to the protection member.

  According to the above configuration, by fixing the angle sensor side and rotating the marker side, wiring of the angle sensor becomes easy, and it is not necessary to measure the rotation angle by extending the shaft from the connection pin. The entire circumference of the sensor or marker can be protected.

In the fourth invention, in the second or third invention,
The detection member mounting bracket is formed with the pin contact surface and a fitting recess that fits into one end of the connection pin.

  According to said structure, when the recessed part for a fitting fits into the end of a connection pin, it becomes difficult to carry out centering with respect to the marker or angle sensor which the detection member attachment bracket provided in the end of the connection pin.

In the fifth invention, in the second or third invention,
The detection member mounting bracket is formed with the pin contact surface at the tip and an annular rib that fits into a pin insertion hole into which the connection pin is inserted.

  According to the above configuration, the annular rib is fitted into the pin insertion hole, so that the detection member mounting bracket is less likely to be misaligned with respect to the angle sensor or marker provided at one end of the connection pin.

In a sixth invention, in any one of the first to fifth inventions,
The elastic member is a leaf spring fixed to the detection member mounting bracket.

  According to the above configuration, a simple and inexpensive configuration can be achieved even in a narrow space.

In a seventh invention, in any one of the first to sixth inventions,
The first member is an arm,
The second member is an idler link to which a tip attachment is attached.

  According to the above configuration, the sensor can be protected even at the tip portion where earth and sand or metal pieces easily come in contact, and the rotation angle of the tip attachment is reliably detected. Contact can be reliably prevented, and the tip attachment can be used safely in the widest possible range.

  As described above, according to the present invention, the elastic member urges the detection member mounting bracket to which the angle sensor or the marker is fixed toward the one end of the connection pin provided with the marker or the angle sensor. Thus, the positional relationship between the angle sensor and the marker can be maintained following the axial displacement of the connection pin.

It is a disassembled perspective view which expands and shows an angle sensor apparatus and its periphery. 1 is a side view showing a hydraulic excavator according to an embodiment of the present invention. It is a perspective view which shows an arm. It is a side view which expands and shows the arm front-end | tip. It is a side view which expands and shows the arm tip further. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. FIG. 7 is an enlarged sectional view of a portion VII in FIG. 6. It is a side view which expands and shows a cylindrical outer peripheral wall and an attaching part. It is a front view which expands and shows a cylindrical outer peripheral wall, an attaching part, and a cover member. FIG. 8 is an equivalent diagram of FIG. 7 according to a modification of the embodiment of the present invention.

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

-Configuration of hydraulic excavator-
FIG. 2 shows a hydraulic excavator 1 as a working machine according to an embodiment of the present invention. The hydraulic excavator 1 includes a lower traveling body 2 and an upper revolving body 3 that can swivel on the lower traveling body 2. . A boom 4 as an attachment is supported on the upper swing body 3 by a boom cylinder 5 so as to be raised and lowered. A driver's cab 3 a is provided on the front side of the upper swing body 3. An arm 6 as a first member is rotatably connected to the tip of the boom 4 and is rotated by extending and contracting the arm cylinder 7.

  A crushing device 8 as a tip attachment is rotatably connected to the tip of the arm 6 by a tip cylinder 9, an idler link 10 and a bucket link 11 as a second member. The tip attachment is not limited to the crushing device 8 and may be various buckets, lifting magnets, grapples, and the like. As shown in FIG. 5 and the like, the crushing device 8 is connected to the arm 6 by the arm side connecting pin 13 and connected to the bucket link 11 by the link side connecting pin 14.

  As shown in the rotation range in FIG. 4, the idler link 10 is provided in a pair on the left and right sides and is coupled to the arm 6 so as to be rotatable about the connection pin 12. In this embodiment, the connection pin 12 is provided on the arm 6 so as to rotate together with the idler link 10. The arm 6 is provided with an angle sensor device 20 that detects a rotation angle of the idler link 10 with respect to the arm 6.

  As shown in FIG. 6, the connection pin 12 is prevented from rotating by a rotation preventing member 12b made of a bolt or the like, and an axial dimension L between the flange portion 12a and the rotation preventing member 12b is set. A pair of idler links 10, a pair of bushes 12c, and a spacer 12d are provided between the flanges 12a and the anti-rotation member 12b. The gap can be adjusted to some extent by a shim (not shown). However, the axial dimension L between the flange 12a and the detent member 12b is set with some margin so that the dimensional error of these members can be absorbed. Has been.

  The angle sensor device 20 includes a marker 21 provided at the left end portion of the connection pin 12 as viewed from the cab 3a, for example, and an angle sensor 22 provided on the arm 6 to detect the rotation angle of the marker 21.

  The marker 21 is, for example, a disk-shaped or columnar position marker, and a magnet is embedded therein. The marker 21 is pivotally fixed by being fitted to one end of the connection pin 12 or the like.

  The angle sensor 22 is formed of, for example, a magnetic non-contact rotary sensor that captures the direction of a magnetic field with an integrated circuit and outputs the calculated angle as an analog signal. The misalignment or distance between the sensor body of the angle sensor 22 and the marker 21 needs to be within an allowable range. The angle sensor 22 is attached to the arm 6 so as not to rotate.

  Specifically, the angle sensor 22 is attached to a sensor attachment bracket 23 as a detection member attachment bracket having a circular cross-sectional shape of a cap. The periphery of the sensor mounting bracket 23 is covered with a protective member 26 having a protective portion main body 24 and a mounting portion 25 for fixing the protective portion main body 24 to the arm 6. The protection unit main body 24 includes, for example, a cylindrical outer peripheral wall 27 formed by bending a steel plate into a substantially octagonal shape, and a lid member 28 fixed to the cylindrical outer peripheral wall 27. For example, attachment portions 25 are formed at both ends of the cylindrical outer peripheral wall 27, respectively. The mounting portion 25 is fastened to the tapped block 15 provided on the arm 6 by a mounting bolt 30 inserted through the bolt insertion hole 25a. The cylindrical outer peripheral wall 27 is not an octagonal cylinder, but may be another polygonal cylinder such as a hexagonal cylinder or a square cylinder, or may be a cylinder or an elliptic cylinder.

  The plate-like lid member 28 has, for example, a substantially octagonal shape according to the inner periphery of the protection part main body 24, and is fixed to a fixing part 27 a protruding from the inner surface of the protection part main body 24 with fixing bolts 31. An anti-rotation pin 28 a protrudes from the back surface side of the lid member 28. By inserting the anti-rotation pin 28 a into an engagement hole 23 a provided in the sensor mounting bracket 23, the angle sensor 22 is attached to the lid member 28. Against rotation. As shown in an enlarged view in FIG. 7, a leaf spring 32 as a double-armed elastic member, for example, is attached to the sensor attachment bracket 23 with a spring attachment screw 32a. As indicated by broken lines in FIG. 9, the fixing bolt 31 is in a position that does not protrude from the cylindrical outer peripheral wall 27 in a state where the lid member 28 is attached to the fixing portion 27 a. For this reason, the bolt head of the fixing bolt 31 does not hit the foreign matter and the fixing bolt 31 and its surroundings are not damaged.

  The sensor mounting bracket 23 is covered with a gap by a protective member 26 fixed to the arm 6, and the leaf spring 32 is provided in a gap C 3 between the inner surface of the protective member 26 and the sensor mounting bracket 23. Yes. The two arms having elasticity of the leaf spring 32 abut on the back side of the lid member 28, so that the fitting recess 23b of the sensor mounting bracket 23 is pressed against the flange 12a of the connection pin 12, and the sensor mounting bracket 23 is It does not wobble and is difficult to misalign.

  The idler link 10 is provided with a movement restricting member 29 that restricts the movement of the protection unit main body 24. In the present embodiment, the movement restricting member 29 is formed of a ring-shaped protrusion provided on the left side surface of the idler link 10 by welding or the like. The outer diameter of the movement restricting member 29 is smaller than the minimum inner diameter of the cylindrical outer peripheral wall 27, and the outer peripheral wall of the movement restricting member 29 is covered with the cylindrical outer peripheral wall 27. That is, the movement restricting member 29 is disposed inside the cylindrical outer peripheral wall 27.

  And if the clearance gap between the edge part by the side of the idler link 10 of the cylindrical outer peripheral wall 27 and the arm 6 is made into the 1st clearance gap C1, the height H of the movement control member 29 will be higher than the 1st clearance gap C1. (H> C1). The second gap C <b> 2 between the marker 21 and the angle sensor 22 has a predetermined allowable range in order to exhibit the function of the angle sensor 22. A gap C3 between the lid member 28 provided with the leaf spring 32 and the sensor mounting bracket 23 is set larger than these gaps C1 and C2. In the present embodiment, the outer diameter of the movement restricting member 29 is made smaller than the minimum diameter of the cylindrical outer peripheral wall 27 and the outer periphery of the movement restricting member 29 is covered with the cylindrical outer peripheral wall 27. 29 may cover the outer periphery of the cylindrical outer peripheral wall 27. Further, the movement restricting member 29 may not be a continuous ring-shaped protrusion, but may be a set of arc-shaped protrusions interrupted in the middle.

  As shown in FIG. 4, the cable 22 a of the angle sensor 22 is covered with a cable protection bracket 22 b attached to the left side surface of the arm 6.

-Operation of the angle sensor device-
In the connection pin 12 in the hydraulic excavator 1 configured as described above, due to a manufacturing tolerance relationship of components such as the idler link 10, the bush 12c, the spacer 12d, and the like provided between the rotation prevention member 12b and the flange portion 12a, The axial dimension L between the anti-rotation member 12b and the flange portion 12a is designed so that there is a certain gap in the axial direction. In addition, due to aging or the like, each component is worn or deformed, and thus looseness occurs. However, in this embodiment, the leaf spring 32 presses the sensor mounting bracket 23 to which the angle sensor 22 is mounted against one end side of the connection pin 12, and the sensor mounting bracket 23 moves in the axial direction of the connection pin 12 with respect to the arm 6. By doing so, dimensional errors and backlash of the axial dimension L are absorbed. Thereby, since the space | interval of the marker 21 and the angle sensor 22 is maintained by the predetermined space | interval, an exact rotation angle is detected.

  In the present embodiment, by fixing the angle sensor 22 side and rotating the marker 21 side, wiring of the angle sensor 22 is facilitated, and it is not necessary to extend the shaft from the connection pin 12 to measure the rotation angle. Therefore, the entire circumference of the angle sensor 22 can be protected.

  When the tip cylinder 9 expands and contracts and the idler link 10 rotates during the operation of the crushing device 8, the connection pin 12 that rotates integrally with the idler link 10 rotates together with the marker 21, and the rotation angle is set to the arm 6. The angle sensor 22 attached so as not to rotate is detected. Thereby, since the working posture of the crushing device 8 can also be grasped, it is only necessary to prevent contact with the cab 3a and the like based on the working posture together with the raising / lowering angle control of the boom 4. For this reason, it is not always considered that the crushing device 8 is most likely to hit the driver's cab 3a or the like as in the prior art, and contact prevention control is performed, but it is possible to work in as wide a range as possible while grasping the posture of the crushing device 8. Contact prevention control may be performed so that

  Therefore, according to the working machine according to the present embodiment, the leaf spring 32 urges the sensor mounting bracket 23 to which the angle sensor 22 is fixed toward one end of the connection pin 12 provided with the marker 21. The positional relationship between the angle sensor 22 and the marker 21 can be maintained following the axial displacement of the connection pin 12.

-Modification-
FIG. 10 shows a modification of the embodiment of the present invention, which differs from the above embodiment in that the contact structure between the connection pin 112 and the sensor mounting bracket 123 is different. In addition, in this modification, the same code | symbol is attached | subjected about the same part as FIGS. 1-9, and the detailed description is abbreviate | omitted.

  In this modification, there is no flange of the connection pin 112, the tip of the annular rib 123 b formed protruding from the sensor mounting bracket 123 is inserted into the pin insertion hole 10 a, and its pin contact surface 123 c is the connection pin 112. It is in contact with the tip. A fourth gap C <b> 4 is maintained between the outer peripheral edge of the annular rib 123 b of the sensor mounting bracket 123 and the side surface of the idler link 10.

  In this modification, the sensor mounting bracket 123 is less likely to be misaligned with respect to the marker 21 provided at one end of the connection pin 112 by fitting the annular rib 123b into the pin insertion hole 10a.

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

  That is, in the above embodiment, the angle sensor 22 is provided on the sensor mounting bracket 23 as the detection member mounting bracket, and the marker 21 is provided on the connection pin 12. On the contrary, the angle sensor 22 is provided on the connection pin 12, and the sensor mounting bracket is provided. A marker 21 may be attached to 23. In this case, it is necessary that the cable 22a does not hinder the rotation of the connection pin 12. However, for example, if the wireless angle sensor 22 is used, the cable 22a becomes unnecessary.

  In the said embodiment, although the 1st member was the arm 6 and the 2nd member was the idler link 10, it is not limited to this. For example, the first member may be a boom and the second member may be an arm.

  In the above-described embodiment, the elastic member is the leaf spring 32. However, the elastic member is not limited to this and may be constituted by a compression coil spring, a rubber member, or the like.

  In the above embodiment, the angle sensor 22 is a sensor that detects an angular position by a magnetic field, but a non-contact sensor such as an infrared sensor or other optical sensor may be used.

  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.

1 Hydraulic excavator (work machine)
2 Lower traveling body
3 Upper swing body
3a cab
4 Boom
5 Boom cylinder
6 Arm (first member)
7 Arm cylinder
8 Crushing device (tip attachment)
9 Tip cylinder
10 idler link (second member)
10a Pin insertion hole
11 Bucket links
12 connection pins
12a Isobe
12b Non-rotating member
12c bush
12d spacer
13 Arm side connecting pin
14 Link side connecting pin
15 Tapped block
20 Angle sensor device
21 Markers
22 Angle sensor
22a cable
22b Cable protection bracket
23 Sensor mounting bracket (Sensing member mounting bracket)
23a engagement hole
23b Recess for fitting
24 Protection unit body
25 Mounting part
26 Protection member
27 Cylindrical outer peripheral wall
27a fixed part
28 Lid member
28a Non-rotating pin
29 Movement restriction member
30 Mounting bolt
31 Fixing bolt
32 Leaf spring (elastic member)
32a Spring mounting screw 112 Connection pin
123 Sensor mounting bracket
123b annular rib
123c Pin contact surface
H Axial dimension of connecting pin

Claims (6)

A first member; a second member coupled to the first member so as to be rotatable about a connection pin; and an angle sensor device that detects a rotation angle of the second member relative to the first member. A working machine equipped with,
The connection pin is provided on the first member so as to rotate integrally with the second member;
The angle sensor device is
A marker provided on one end of the connection member and a detection member mounting bracket having a pin contact surface in contact with one end of the connection pin in an assembled state ;
An angle sensor that is provided at one end of the connection pin and the other of the detection member mounting bracket at a predetermined distance at a position facing the marker, and detects a rotation angle of the marker;
The detection member mounting bracket is attached to the first member so as to be movable in the axial direction of the connection pin, and is biased toward one end of the connection pin by an elastic member ,
The detection member mounting bracket is covered with a gap by a protective member fixed to the first member,
The elastic member is provided in the gap between the inner surface of the protection member and the detection member mounting bracket, the proximal end side is fixed to the detection member mounting bracket, and the distal end side of the protection member is in the assembled state. A work machine configured to be in contact with an inner surface . The work machine according to claim 1 ,
The work machine, wherein the detection member mounting bracket is provided so as not to rotate with respect to the protection member. In the work machine according to claim 1 or 2 ,
The working machine, wherein the detection member mounting bracket is formed with a pin contact surface and a fitting recess that fits into one end of the connection pin. In the work machine according to claim 1 or 2 ,
The work machine according to claim 1, wherein the detection member mounting bracket is formed with an annular rib that is formed with a pin abutting surface at a tip and is fitted into a pin insertion hole into which the connection pin is inserted. The work machine according to any one of claims 1 to 4 ,
Wherein the elastic member is the proximal end side abuts against the inner surface of the detecting member mounting bracket to be fixed Rutotomoni, the protective member dual arm portion having elasticity is in assembled state, a leaf spring of a double-arm shape Work machine. In the work machine according to any one of claims 1 to 5 ,
The first member is an arm,
The work machine, wherein the second member is an idler link to which a tip attachment is attached.

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