JPH0637785B2 - Position measuring device of arm tip pin in hydraulic excavator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the position of an arm tip pin in a hydraulic excavator, and more specifically, for measuring an excavation depth in excavation work or a crane for an arm tip pin. The present invention relates to a measuring device that can easily measure a working radius when a crane work is performed by attaching a hook for the work.

[Conventional technology]

The boom and arm circuit angles of the hydraulic excavator are electrically detected, the tip position of the bucket is calculated based on the detection signal, the value is displayed, and straight line bucket excavation work (excavation surface finishing work) is performed. Various automatic control devices have been proposed.

[Problems to be solved by the invention]

It is easy to measure the position of the arm tip pin in the driver's cab by using the above electrical detection means, but in the excavation work of a normal hydraulic excavator that requires severe work, The angle detector is damaged early due to the impact reaction such as. Further, since it is detected electrically, there is a risk of malfunction due to water immersion in the case of underwater excavation, so there is a problem in reliability and the apparatus itself becomes expensive. Further, Japanese Utility Model Laid-Open Publication No. 59-125556 has been proposed as a device for mechanically detecting the boom angle and the arm angle. However, since the boom and the arm angle meter are located near the arm mounting shaft at the tip of the boom, the operator's cab It is far away and hard to see from the operator. For this reason, there is no choice but to use a signal man outside the driver's cab to read the angle and inform the operator, or the operator must go down from the driver's cab to look at it. In addition, 59-122
The rated load disclosed in Japanese Patent No. 5556 is difficult to read because it is a list of numbers, and when the boom angle and the arm angle have intermediate values, it takes time to obtain the rated load by linear interpolation.

The present invention has been made in view of such problems,
The purpose is to be able to withstand severe excavation work, to operate reliably and at a low cost, and for the operator to easily measure while sitting in the driver's seat. To provide a position measuring device.

[Means for solving problems]

In order to achieve this object, the present invention provides a boom angle meter for displaying the rotation angle of the boom on a scale plate with a pendulum needle on the side of the lower cabin side of the boom, and a parallel link mechanism for measuring the rotation angle of the arm with respect to the boom. Install the arm angle meter that displays on the scale plate by using one side of the parallel link as an indicator needle, and at the appropriate place in the cab, set the boom foot pin position, boom length and arm length, and boom It is characterized in that a work height conversion table or a work radius conversion table displayed by a diagram is installed by calculating a work height or a work radius of the arm tip pin obtained by the angle and the arm angle.

[Action]

With such a configuration, the operator visually checks the boom angle meter and the arm angle meter in the cab, reads the actual boom angle and the arm angle, and according to the conversion table,
The working height or working radius at that time can be easily and surely measured.

〔Example〕

FIG. 9 is a side view of the entire hydraulic excavator according to the present invention, in which the hydraulic excavator main body 1 is composed of a lower traveling body and an upper revolving superstructure. The base end of the boom 2 is rotatably attached to the front of the hydraulic excavator body 1 by a boom foot pin 10, and the arm 3 is rotatably attached to the tip of the boom 2 by a boom tip pin 11. The bucket 4 is rotatably attached to the tip of the arm 3 by the arm tip pin 12. 5 is a boom cylinder mounted between the hydraulic excavator body 1 and the boom 2, 6 is an arm cylinder mounted between the boom 2 and the arm 3, 7 is the arm 3 and the first link 8, and the second link 9 It is a bucket cylinder attached between and.
The other end of the first link 8 is attached to the arm 3 and the other end of the second link 9 is attached to the bucket 4. Reference numeral 13 is a pin for attaching the boom cylinder 5 to the boom 2.

Then, the boom 2, the arm 3, and the bucket cylinder 7 are extended and contracted to rotate the boom 2, the arm 3, and the bucket 4, and the excavation work is performed.

Further, a crane hook 40 is attached to the arm tip pin 12, and the crane work is performed by the expansion and contraction operations of the boom cylinder 5 and the arm cylinder 6.

In FIG. 9, 1a is the center of rotation of the hydraulic excavator body 1, 2a is the first boom base line connecting the boom foot pin 10 and the boom tip pin 11, and 3a is the boom tip pin 11 and the arm tip pin 12. The connected arm base line, R is the horizontal distance from the turning center 1a to the arm tip pin 12,
That is, working radius, H is the vertical distance from the ground to the arm tip pin 12, that is, working height, R _B is the horizontal distance from the swing center to the boom foot pin 10, and H _B is the vertical distance from the ground to the boom foot pin 10. , R are the toes 4 of the bucket 4
The rotation radii of a are shown respectively.

Therefore, the measuring device of the present invention measures the position of the arm tip pin 12, that is, the working height H required for excavation work or the working radius R required for crane work.

Next, one embodiment of the boom angle meter and the arm angle meter will be described with reference to FIGS. 1 to 6. FIG. 1 is a side view of an essential part showing a state in which the arm 3 is folded to the side of the boom 2, FIG. 2 is a view taken along arrow A of FIG. 1, FIG. 3 is a view taken along arrow B of FIG. 1, and FIG. 1 is a view taken along arrow C of FIG. 1, FIG. 5 is a partially enlarged view of FIG. 1, and FIG. 6 is a view taken along arrow D of FIG. The boom and arm angle meter constituting the present invention is for detecting the postures of the boom 2 and the arm 3 and for easily notifying the position of the arm tip pin 12. To this end, the first boom baseline 2a
And the angle of the arm base line 3a must be measured.

First, the boom angle meter will be described. On the side surface of the boom 2 on the lower cab side, a scale plate 32 for displaying the rotation angle of the boom 2 by a known pendulum needle 30 via a pin 31 is provided. Thereby, the inclination θ _B of the first boom base line 2a with respect to the horizontal is measured.

Next, the arm angle meter will be described. The arm angle meter displays the rotation angle θ _A of the arm 3 with respect to the boom 2 on the scale plate 29 provided on the side surface of the boom 2 on the lower cab side by the two parallel link mechanisms and the indicating needle 27. .
First, the second boom base line 2b connecting the boom tip pin 11 and the attachment pin (the rotation center pin of the lever 20) 13 of the boom cylinder 5 to the boom 2, and the pin 13 and the indicator needle 2 are connected.
The third boom base line 2c connecting the mounting pin 28 of No. 7 is formed. Next, the bracket 14 attached to the base end of the arm 3 at a position separated from the boom tip pin 11 by a radius of rotation r ₁ and the first tip 20a of the lever 20 separated from the pin 13 by a radius of rotation r ₁ And are connected by a rod 17. As a result, the second boom baseline 2b and the bracket 1
4, the rod 17 and the first tip 20a of the lever 20 form a parallelogram. Here, FIG. 2 and FIG.
As shown in the figure, the bracket 14 and one end of the rod 17 are connected by an L-shaped joint 15 and fixed by a nut 16. The first tip 20 a of the lever 20 and the other end of the rod 17 are connected by an L-shaped joint 18 and fixed by a nut 19. According to this structure, the rotation angle displacement of the arm base line 3a due to the expansion and contraction of the arm cylinder 6 is surely transmitted to the rotation angle displacement of the lever 20, and the two displacement amounts are equal.

Next, the lever 20 separated from the pin 13 by a turning radius r ₁
The second tip portion 20b of the above and the tip portion of the indicator needle 27 which is separated from the pin 28 by the radius r _{2 of} rotation are connected by a rod 22. Accordingly, the third boom base line 2c, the second tip portion 20b of the lever 20, the rod 22, and the indicating needle 27 form a parallelogram. Here, as shown in FIG. 4, the second tip portion 20 b of the lever 20 and one end portion of the rod 22 are connected by an L-shaped joint 23 and fixed by a nut 24. In addition, the tip of the indicator needle 27 and the rod 2
The other end of 2 is connected by an L-shaped joint 25, and is fixed by a nut 26. With this configuration, the rotation angle displacement of the lever 20 is reliably transmitted to the rotation angle displacement of the indicating needle 27, and the two displacement amounts are equal. Both scale plates 2
As shown in FIG. 5, if the reference numerals 9 and 32 are attached to the boom 2 via the bracket 33, the attachment of the scale plate to the boom 2 is simplified.

Therefore, the rotation angle displacement of the arm base line 3a with respect to the first boom base line 2a is surely transmitted to the rotation angle displacement of the indicator needle 27 via the lever 20 and displayed on the scale plate 29 as an arm angle.

In this embodiment, the rotation center pin 13 of the lever 20 is aligned with the attachment pin of the boom cylinder 5 to the boom 2.
It may be anywhere on the side of the bent portion of the boom 2. Also,
Threaded L-shaped joints 15, 18, 23, 25 having adjustable lengths are used at both ends of the rods 17, 22, but the present invention is not limited to this, and for example, a pin connection or the like. Freely moveable bracket 14 and lever 20 tip 2
0a, 20b and any one capable of being pivotally supported by the indicating needle 27 may be used.

Next, as shown in FIG. 1, the linear distance from the boom foot pin 10 to the boom tip pin 11 (the first boom baseline 2
The length of a) L _B is the boom length, and the linear distance from the boom tip pin 11 to the arm tip pin 12 (arm base line 3a
When the arm length is L _A , the working height H in FIG. 9 can be expressed by the following equation from the boom angle θ _B and the arm angle θ _A described above.

H = H _B + L _B × sin θ _B −L _A × sin (θ _B + θ _A ) Here, the height position H _B of the boom foot pin 10, the boom length L _B , the arm length L _A, and the bucket 4 The turning radius r of the toe 4a is preset according to the specifications of the hydraulic excavator (meaning the size determined by the body weight, bucket capacity, etc.) and can be expressed as a constant, so the working height H is the boom angle. It can be displayed as a function of θ _B and arm angle θ _A. FIG. 7 shows, as an example, a working height conversion table 41 for a hydraulic excavator having a bucket capacity of 0.45 m ³ . H _B = 1.5 m, L _B = 4.6 m, L _A = 3
Since the m and r are set to 1.2 m respectively, if the horizontal axis is the boom angle θ _B and the vertical axis is the arm angle θ _A , the working height H should be calculated and displayed as a curve shown in FIG. 7. You can Incidentally, FIG. 7 shows the minimum arm angle θ _A = 0 when the arm cylinder 6 is extended most and the arm 3 is held up most.
Is displayed as. If this working height conversion table 41 is attached to a suitable place in the driver's cab, for example, on the windshield, the operator of the hydraulic excavator can visually check the boom angle meter and the arm angle meter in the driver's cab, and If the boom angle θ _B = 20 ° and the arm angle θ _A = 70 °, H = 0.5 m can be easily obtained from the work height conversion table 41. Here, when H is displayed as a negative value, it indicates the excavation depth from the ground. In addition, when the excavation depth of the bucket 4 is obtained, the toe 4a of the bucket 4 is
The radius of rotation r of is considered in this value H. Since r = 1.2 m in this embodiment, the excavation depth H ′ of the bucket 4 is H ′ = H−r = −0.7 m, and the excavation depth H ′ = 0.
It can be easily calculated as 7 m.

Next, a case will be described in which the working radius R is measured during crane work in which the crane hook 40 is attached to the arm tip pin 12. Working radius R from FIGS. 1 and 9
Can be expressed by the following equation.

R = R _B + L _B × cos θ _B −L _A × cos (θ _B + θ _A ) where the distance R _B from the swing center 1a of the boom foot pin 10, the boom length L _B, and the arm length L _A are Since it is preset as described above, it can be expressed as a constant, so the working radius R can be expressed as a function of the boom angle θ _B and the arm angle θ _A. FIG. 8 shows a working radius conversion table 42 of a hydraulic excavator having a bucket capacity of 0.45 m ³ as an example. R _B = 0.14 m, L _B
= 4.6m and L _A = 3m,
Taking the boom angle θ _{B on} the horizontal axis and the arm angle θ _A on the vertical axis,
The working radius R can be calculated and displayed as a curve shown in FIG. In addition, FIG. 8 shows the minimum arm angle θ _A when the arm cylinder 6 is fully extended and the arm 3 is most held up.
It is displayed as = 0. This work radius conversion table 4
If 2 is attached to a suitable place in the driver's cab, for example, on the windshield, the operator of the crane can visually check the boom angle meter and the arm angle meter in the driver's cab and, for example, the boom angle θ _B = 20 °. If the arm angle θ _A = 70 °, R = 6 m can be easily obtained from the working radius conversion table 42. Although not shown, the crane hook 40 shown in FIG. 9 has a built-in load cell (load cell).
By displaying the actual load measured by the load meter in the operator's cab, stable crane work can be performed from the actual load and the allowable load determined according to the working radius.

That is, the value of the working radius shown in each curve of the working radius conversion table of FIG. 8 is displayed as an allowable load value to form an allowable load conversion table, and the safe crane work can be performed by the allowable load and the actual load. can get.

〔The invention's effect〕

As described above, according to the present invention, the boom angle meter that displays the rotation angle of the boom on the scale plate by the pendulum needle, and the rotation angle of the arm with respect to the boom are displayed on the scale plate by the parallel link mechanism and the indicator needle. The arm angle meter for the arm to be mounted on the side of the lower cabin side of the boom, and the arm tip pin determined by the preset boom foot pin position, boom length and arm length, and boom angle and arm angle. Since the work height conversion table or the work radius conversion table that was calculated by calculating the position of the With the table, the actual work height or work radius can be easily and surely measured. Further, even if the boom angle and the arm angle have intermediate values, it is possible to easily interpolate between the two curves from the position of the intersection, so that the working height and working radius can be read in a short time. As a result, the work performance of ordinary excavating work of a hydraulic excavator or crane work in which a hook for a crane is attached to an arm tip pin can be significantly improved. Further, since the boom angle meter and the arm angle meter of the present invention are displayed on the boom base end portion by the mechanical transmission means, the operator can visually check both angle meters at a glance. Since the excavation load does not act, the impact reaction force is less affected and it is possible to withstand severe excavation work and the like. It also operates reliably, so it is highly reliable.
Further, the measuring device of the present invention is composed of the angle meter means attached to the side surfaces of the boom and the arm, and the conversion table installed in the cab, so that the structure can be simply provided at low cost,
It has a great practical effect that it can be easily attached to a hydraulic excavator work machine.

[Brief description of drawings]

1 to 9 show an embodiment of the present invention.
FIG. 1 is a side view of a main part of a boom and arm angle meter showing a state in which an arm is folded to a boom side, FIG. 2 is a view taken along arrow A of FIG. 1, and FIG. 3 is a view taken along arrow B of FIG. 4, FIG. 4 is a view on arrow C of FIG. 1, FIG. 5 is a partially enlarged view of FIG. 1, FIG. 6 is a view on arrow D of FIG. 5, and FIG. 7 is a bucket capacity of 0.45 m ³ class. Fig. 8 is a working height conversion table for a hydraulic excavator, Fig. 8 is a working radius conversion table for a hydraulic excavator with a bucket capacity of 0.45 m ³ , and Fig. 9 is an overall side view of a hydraulic excavator according to the present invention.

Claims (2)

[Claims] 1. A boom angle meter for displaying a rotation angle of the boom on a scale plate by a pendulum needle, a rotation angle of the arm with respect to the boom, and two parallel link mechanisms and one side of the parallel link. Attach the arm angle meter that displays on the scale plate by using it as an indicator needle, and at the proper position in the cab, set the boom foot pin position in advance,
An arm for a hydraulic excavator, in which a working height conversion table is installed which is calculated by calculating the working height of the arm tip pin, which is obtained from the boom length and arm length, and the boom angle and arm angle. Tip pin position measuring device. 2. A boom angle meter for displaying the rotation angle of the boom on a scale plate by a pendulum needle on the side of the lower cabin side of the boom, and the rotation angle of the arm with respect to the boom for two parallel link mechanisms and one side of the parallel link. Attach the arm angle meter that displays on the scale plate with the indicator needle, and find the boom foot pin position, boom length and arm length, and boom angle and arm angle that are set in advance in the proper place in the cab. An arm tip pin position measuring device for a hydraulic excavator, which is provided with a work radius conversion table that calculates a work radius of the arm tip pin and displays it as a diagram.