JP3717026B2 - Power shovel arm angle detector mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mounting structure for an arm angle detector of a power shovel.
[0002]
[Prior art]
As illustrated in FIG. 6, the so-called power shovel has left and right side plates 1L, 1R at the upper part of the rear end, and the tip of the arm hydraulic cylinder Ca is pin-connected by a first horizontal pin P1 between the left and right side plates 1L, 1R. In addition, the lower end of the rear end is pin-connected to the tip of the boom 2 by the second horizontal pin P2, and the rear end of the arm hydraulic cylinder Ca is connected to the upper portion by the third horizontal pin P3 and the base end is the fourth. The boom 2 is connected to the vehicle body 3 by a horizontal pin (not shown). And it has various working tools, such as a bucket and a breaker, at the tip of the arm 1 to perform excavation work and crushing work with high efficiency.
[0003]
The example machine shown in FIG. 6 divides the boom 2 into three parts and connects them with vertical pins or horizontal pins, and has an offset cylinder. With these, the arm 1 and the vehicle body 3 are maintained while maintaining the posture of the vehicle arm 1. 3 is an example of an offset excavator that can turn left and right. Various other types of power shovels are common in that they have the arm 1 and the boom 2 configured as described above.
[0004]
In such a power shovel, a detector body provided on the arm 1 side with a relative rotation angle θ relative to the boom 2 of the arm 1 that rotates about the second horizontal pin P2 in accordance with expansion and contraction of the arm hydraulic cylinder Ca. Some have an arm angle detector 4 for detecting the amount of movement of a detection link 4b (not shown) extending from 4a (not shown) to the boom 2 side. The detected angle θa detected by the arm angle detector 4 is input to a controller (not shown) such as a microcomputer mounted on the vehicle and used as an information source for automatic excavation control and the like. There are various detector bodies 4a. Although not shown, for example, an absolute encoder that includes a rotating body pin-connected to the base end of the detection link 4b and is provided between the rotating body and the base inside the detector body 4a. In most cases, the rotation angle of the rotating body corresponding to the amount of movement of the detection link 4b is output as the detection angle θa by a rotation angle detecting element such as a resistance potentiometer or the like. Depending on the arrangement of the arm angle detector 4 (particularly, the number of links of the detection links 4b and the mounting position of the tip on the boom 2 side, etc.), the detection angle θa must be corrected so that it does not coincide with the relative rotation angle θ. However, this correction is usually corrected by the controller (the same applies hereinafter).
[0005]
As an attachment structure of the arm angle detector 4 of such a power shovel, for example, as disclosed in Japanese Patent Application Laid-Open No. 718707, arm angle detection is performed on one of the outer surfaces of the arm 1 and the left and right side plates 1L and 1R. It is usual to provide a vessel 4. However, since the arm angle detector 4 protrudes greatly outward, the arm angle detector 4 interferes with the peripheral fixing member during work and is damaged. In order to solve this problem, techniques disclosed in Japanese Patent Application Laid-Open Nos. Hei 6-228989, Hei 8-81974, and Hei 8-239866 are known. Next, the technical outline described in these publications will be described next. Note that the same reference numerals are assigned to the same elements as those in FIG. 6 to facilitate comparison.
[0006]
(1) Japanese Patent Laid-Open No. 6-228989 discloses a technique in which an arm angle detector 4 is provided between the left and right side plates 1L and 1R, and the tip of the detection link 4b is pin-connected to the tip of the arm hydraulic cylinder Ca. ing.
(2) Japanese Patent Laid-Open No. 8-81974 has left and right side plates 1L and 1R of a size that completely hides the arm angle detector 4 in a side view in the technique described in Japanese Patent Laid-Open No. 6-228989. It is described.
(3) In JP-A-8-239866, in the technique described in the above-mentioned JP-A-8-81974, the upper and lower sides of the detector body 4a can be protected with a protective cover provided between the left and right side plates 1L and 1R. Has been described.
[0007]
[Problems to be solved by the invention]
However, the above prior art has the following problems. Recently, excavators are required to be miniaturized so that they can operate in the city and in Kushiro. That is, the arm 1 is also miniaturized, and therefore the width between the left and right side plates 1L, 1R must be narrowed. By the way, it is economical to use a standard product for the arm angle detector 4 and, therefore, there is no freedom in selecting the size. That is, the above-described technologies (the technologies disclosed in JP-A-6-228989, JP-A-8-81974, and JP-A-8-239866) all include the arm angle detector 4 between the left and right side plates 1L, 1R. Therefore, it cannot cope with miniaturization. Therefore, the left and right side plates 1L and 1R are provided wider than the width of the arm 1, or the arm angle is detected on the outer surface of either the arm 1 or the left and right side plates 1L and 1R as disclosed in Japanese Patent Laid-Open No. 718707. Actually, the container 4 is provided so as to protrude greatly outward.
[0008]
An object of the present invention is to provide a mounting structure for an arm angle detector of a power shovel that can cope with the miniaturization and does not interfere with a peripheral fixing member.
[0009]
[Means and effects for solving the problems]
In order to achieve the above object, the first mounting structure of an arm angle detector for a power shovel according to the present invention has left and right side plates 1L, 1R at the upper rear end, and arm hydraulic pressure between the left and right side plates 1L, 1R. The front end of the cylinder Ca is pin-connected by the first horizontal pin P1, the lower end of the rear end is connected to the front end of the boom 2 by the second horizontal pin P2, and the rear end of the hydraulic cylinder Ca for the arm is third. It is mounted on a power shovel having a pin connected by a horizontal pin P3 and a base end connected to the vehicle body 3 by a fourth horizontal pin, and around the second horizontal pin P2 according to the expansion and contraction of the arm hydraulic cylinder Ca. Arm angle detection of a power shovel that detects the relative rotation angle θ of the arm 1 rotating in the direction of the boom 2 in accordance with the operation amount of the detection link 4b extending from the detector body 4a provided on the arm 1 side to the boom 2 side. In the mounting structure of the detector 4, the width between the left and right side plates 1L and 1R is narrower than the left and right width of the arm angle detector 4, and the detection link 4b positioned between the left and right side plates 1L and 1R, and the detection A detector body which is connected to the link 4b and has a rotating shaft 4a1 disposed between the left and right side plates 1L and 1R, and is inserted and fixed in a hole 1a provided in one of the left and right side plates 1L and 1R. 4a.
[0010]
According to the said 1st structure, there exist the following effects. Since the hole 1a is provided in one of the left and right plates 1L and 1R, and the detector body 4a is inserted and fixed in the hole 1a so that the detection link 4b is positioned between the left and right plates 1L and 1R, the left and right plates 1L and 1R are fixed. The gap between them is basically sufficient if the width of the detection link 4b and the tip of the arm hydraulic cylinder Ca can be accommodated. Therefore, it contributes to the miniaturization of the power shovel. Further, when the arm angle detector 4 has a large size, only the thickness of the side plate 1L (or 1R) provided with the hole 1a and the amount protruding between the left and right side plates 1L and 1R are projected outward. Therefore, the opportunity for the arm angle detector 4 to interfere with the peripheral fixing member is reduced by this subtraction allowance. Therefore, interference damage can be greatly reduced. As described above, the maximum effect of the first configuration is that the arm angle detector 4 having no size selection freedom can be used at a low cost and the power shovel can be miniaturized.
[0011]
Second, in the first configuration, the tip of the detection link 4b is extended to the tip of the arm hydraulic cylinder Ca, and the tip is connected by a fifth horizontal pin P5.
[0012]
According to the said 2nd structure, in addition to the effect of a 1st structure, there exist the following effects. From the description of the “Prior Art” section and the description of “the amount of operation of the detection link 4b extending from the detector body 4a provided on the arm 1 side to the boom 2 side” in the preceding stage in the first configuration. As is clear, the tip of the detection link 4b may be pin-connected to the boom 2 anyway. However, if the pins are connected in a dark manner, the detection link 4b becomes complicated and long. However, in the second configuration, the tip of the detection link 4b is pin-connected to the tip of the arm hydraulic cylinder Ca by the fifth horizontal pin P5. That is, the position on the boom 2 side closest to the arm angle detector 4 is the tip of the arm hydraulic cylinder Ca, and thus the detection link 4b can be shortened. As a result, the handling of the detection link 4b is simplified, and the damage is easily prevented.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment will be described with reference to FIGS. The example machine is the power shovel shown in FIG. Accordingly, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, it will be described in advance that the power shovel in the embodiment is an ultra-small power shovel, as will be described in detail later.
[0014]
As shown in FIG. 1, the arm 1 has left and right side plates 1L and 1R erected at the upper rear end, and has a hole 1a at the rear portion of the left side plate 1L. The detector body 4a is inserted into the hole 1a so that the detection link 4b is positioned between the left and right side plates 1L and 1R, and is detachably fixed with bolts (bolt 4c in FIG. 3). On the other hand, the detection link 4b is connected at its base end to the rotating shaft (rotating shaft 4a1 in FIG. 3) of the rotating body built in the detector main body 4a, and the tip is connected to the tip of the arm hydraulic cylinder Ca. Pin-connected at P5. Details are as follows.
[0015]
As shown in FIGS. 2 and 3, the detection link 4b includes a lever 4b1, a sixth lateral pin P6, and a rod 4b2. The lever 4b1 has a base end connected to the end of the rotation shaft 4a1 of the detector body 4a, and a tip connected to the base end of the rod 4b2 by a sixth horizontal pin P6. As described above, the tip of the rod 4b2 is pin-connected to the tip of the arm hydraulic cylinder Ca by the fifth horizontal pin P5 (see FIG. 1).
[0016]
According to the above embodiment, the operations of FIGS. 4 and 5 are performed. FIG. 4 shows the same posture as FIG. 6 and shows the backward tilting posture of the arm 1 based on the extension of the arm hydraulic cylinder Ca (arrow view X1), and FIG. 5 shows the shortening of the arm hydraulic cylinder Ca (arrow view X2). The forward leaning posture of the arm 1 is shown. As the posture of the arm 1 changes, the detection link 4b rotates around the rotation shaft 4a1, the sixth horizontal pin P6, and the fifth horizontal pin P5. The detector body 4a detects the rotation of the rotation shaft 4a1 as the detection angle θa. As described above, the detection angle θa is input to a controller or the like, corrected to the actual relative rotation angle θ, and put to practical use.
[0017]
The effect of the embodiment will be described with reference to FIG. As shown in FIG. 3, the width B1 between the left and right side plates 1L and 1R of the example machine is narrower than the left and right width B2 of the arm angle detector 4 (B1 <B2). In other words, according to the prior art, the power shovel is equipped with the arm angle detector 4 of a size that cannot be mounted at all. That is, as described at the beginning of the description of the present embodiment, it is an ultra-small excavator. Details are as follows.
[0018]
The arm angle detector 4 protrudes outward by an amount B3 obtained by subtracting the thickness t and the dimension B4 of the left side plate 1L from the left-right width B2. For this reason, the chance that the arm angle detector 4 interferes with the peripheral fixing member is reduced by the difference. Therefore, damage due to interference can be greatly reduced. Moreover, the arm angle detector 4 protrudes between the left and right side plates 1L and 1R with a dimension B4, but still has a sufficient margin as shown in the figure. Therefore, the example machine of this embodiment has a possibility of further miniaturization. Since the arm angle detector 4 is a standard product, the adjustment of the outward protrusion amount is preferably performed using a thickness adjustment shim 1c as shown in FIG.
[0019]
In the above embodiment, the fifth horizontal pin P5 is the tip of the arm hydraulic cylinder Ca. In this way, the detection link 4b can be shortened. Specifically: When the posture of the arm 1 changes, the position of the arm angle detector 4 draws a large locus as shown in FIG. In this case, if the tip of the detection link 4b (that is, the position of the fifth horizontal pin P5) is determined without darkness, the detection link 4b is long and has a complex connection of multiple rods 4b2. That is, the fifth horizontal pin P5 may be on the boom 2 side, but the fifth horizontal pin P5 in the above embodiment is the detection link 4b by setting the tip of the arm hydraulic cylinder Ca closest to the arm angle detector 4. Is the shortest. This simplifies the handling of the detection link 4b and makes it easier to prevent damage.
[Brief description of the drawings]
1 is an enlarged plan view of a portion corresponding to a portion P in FIG. 6 according to an embodiment.
FIG. 2 is an assembly diagram of an arm angle detector in the embodiment.
FIG. 3 is an attachment structure diagram of an arm angle detector in the embodiment.
FIG. 4 is a rearward tilt posture diagram of the arm in the embodiment.
FIG. 5 is a forward tilt posture diagram of an arm in the embodiment.
FIG. 6 is a side view of the power shovel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Arm, 1L ... Left side plate, 1R ... Right side plate, 1a ... Hole, 2 ... Boom, 3 ... Vehicle body, 4 ... Arm angle detector, 4a ... Detector main body, 4b ... Detection link, Ca ... Hydraulic cylinder for arm , P1... First lateral pin, P2... Second lateral pin, P3... Third lateral pin, P5.

Claims (2)

Left and right side plates 1L, 1R are provided at the upper rear end, the tip of arm hydraulic cylinder Ca is pin-connected between the left and right side plates 1L, 1R by a first horizontal pin P1, and the lower rear end is secondly connected to the tip of boom 2. The arm 1 pin-connected by the horizontal pin P2, and the boom 2 having the rear end of the arm hydraulic cylinder Ca connected to the upper portion by the third horizontal pin P3 and the base end pin-connected to the vehicle body 3 by the fourth horizontal pin; The relative rotation angle θ of the arm 1 with respect to the boom 2 that rotates about the second lateral pin P2 according to the expansion and contraction of the arm hydraulic cylinder Ca is detected from the detector body 4a provided on the arm 1 side. In the mounting structure of the arm angle detector 4 of the power shovel that detects according to the operation amount of the detection link 4b extended to the boom 2 side,
The width between the left and right side plates 1L, 1R is narrower than the left and right width of the arm angle detector 4, and
A detection link 4b positioned between the left and right side plates 1L and 1R, and a rotation shaft 4a1 connected to the detection link 4b and disposed between the left and right side plates 1L and 1R. A mounting structure for an arm angle detector of a power shovel, comprising: a detector main body 4a inserted and fixed in a hole 1a provided on either side. In claim 1,
A mounting structure for an arm angle detector of a power shovel, characterized in that the distal end of the detection link 4b extends to the distal end of the arm hydraulic cylinder Ca and is connected to the distal end by a fifth horizontal pin P5.

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