KR20110045517A - Pin Type Load Cell for Measuring Load and Excavator with the same - Google Patents

Abstract

PURPOSE: A pin type load cell for measuring load and an excavator including the same are provided to simultaneously measure load and rotate an excavator. CONSTITUTION: A pin type load cell for measuring load comprises a shaft part(51), a supporting part(54), and an attach part(56). The shaft part accomplishes a pin shape. The supporting part is formed on the shaft body at a regular interval. The attach part is formed in the side of a gusset stay. The attach part has a space part and has the diameter smaller than the gusset stay. The strain gage is formed in the boundary surface of the attach part.

Description

Pin Type Load Cell for Measuring Load and Excavator with the Same

The present invention relates to a pin-shaped load cell for load measurement and an excavator having the same, and more particularly, to more accurately measure the external load and the load applied to each part during the operation of a construction machine such as an excavator.

In general, construction machines such as excavators, wheel loaders, forklifts, and cranes are provided with rotating parts for more efficient work. In such a rotating part, a pin is normally coupled to enable rotation, and operations such as excavation, crushing, and transportation are performed by using a hydraulic cylinder. As the hydraulic cylinder operates, the relative position of the construction machine is changed, The work load is transmitted to the construction machine to balance the forces.

Referring to an example of the construction machine as an example, as shown in Figure 1, the conventional excavator 1 is a bucket 20 is rotatably coupled to the tip of the arm (10). In addition, the arm 10 is provided with a hydraulic cylinder 30 so that the bucket 20 is rotatable during operation. The hydraulic cylinder 30 is connected to the arm 10 and the bucket 20 by a plurality of link members 31 and 32.

In addition, one of the link members 32 of the plurality of link members 31 and 32 is coupled to the bracket 21 formed at one end of the bucket 20 by a coupling pin 40, as shown in FIG. The arm 10 and the bucket 20 are rotatably coupled to each other by a coupling pin 41.

The other end of the arm 10 is coupled to the hydraulic cylinder 30, the boom 2 and another hydraulic cylinder 3 via coupling pins 42, 43, 44.

In the conventional excavator 1 having such a configuration, when working an object such as soil or rock, not only the size of the load but also the direction of the working load should be determined together. In the related art, the size and length of the pressure of the hydraulic cylinder 30 are known. The work load of the construction machine was estimated by calculating the magnitude and direction of the load.

In other words, conventionally, a method of measuring the pressure applied to the hydraulic cylinder 30 or using a strain gauge separately attached to each part of the excavator 1, and then indirectly calculating the load by measuring the stress Was used.

Furthermore, the method of separately attaching the strain gauge to the excavator 1 and calculating the load analytically knows the magnitude and direction of the load when the hydraulic cylinder 30 does not measure other data such as the pressure and the working posture. There was a problem that the number tended to be inferior, and the precision was greatly decreased.

Therefore, since the design of the excavator is made in a situation where the exact load size and direction are not known, the reliability of the excavator is lowered, and problems such as cracking or the like occur in arbitrary parts of the excavator during the operation.

Accordingly, the present invention has been invented to solve the conventional problems as described above, by configuring the pin coupled to the rotary part of the excavator as a pin-shaped load cell, it is possible to simultaneously measure the role of the rotary part of the excavator and load measurement, more accurate load An object of the present invention is to provide a load measuring pin-shaped load cell and an excavator provided with the same.

The present invention for achieving the above object, the pin-shaped shaft portion;

A pair of supports protruding and formed at intervals on the shaft portion;

It is formed on the side of each support portion, formed of a diameter smaller than each support portion consists of one or more attachment portion having a space portion,

There is provided a load measuring pin-shaped load cell in which a strain gauge is formed on at least one attachment portion circumferential surface.

Strain gauges formed on each circumferential surface of the attachment portions positioned at both sides at intervals of the attachment portions to measure asymmetrical loads, each of the first and second strain gauge pieces adjacent to each other in parallel and parallel to each other It is a structure that is arranged.

In addition, strain gages formed on each circumferential surface of the attachment portions positioned at both sides at intervals of the attachment portions to measure asymmetrical loads are disposed as two pairs of first strain gauge pieces and second strain gauge pieces facing each other. It is a structure that consists of.

The strain gauges formed on the circumferential surface of the attachment portion located at one of the attachment portions are arranged in a pair of adjacent first strain gauge pieces and second strain gauge pieces.

Two pairs of the first strain gage pieces and the second strain gage pieces constituting the strain gages are arranged to be less than 180 degrees with an angle to be spaced from each other.

The first strain gage pieces and the second strain gage pieces are arranged to form two pairs, each spaced 90 degrees apart from each other.

On the other hand, the present invention is an excavator comprising a bucket, an arm and a link member connected to the bucket, the bucket and the arm is provided with a pin-shaped load cell for load measurement, characterized in that coupled to the load measuring pin-shaped load cell An excavator is provided.

The present invention also provides an excavator including a bucket, an arm and a link member connected to the bucket, and an excavator having a pin-shaped load cell in which the bucket and the link member are coupled to the pin-shaped load cell for load measurement.

Thus, the present invention, by providing a pin-shaped load cell in place of the pin in the connection portion of the excavator, and serves as a pin to be connected, at the same time to accurately measure the magnitude and direction of the load generated during the operation of the excavator It is possible to identify and compensate for weak spots in the manufacture of excavators, and during operation, the worker can grasp the load on the job in real time through a monitor, so that the load can be controlled so as not to be overloaded under specific working conditions.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The same components as in the prior art will be described with the same reference numerals, and detailed description thereof will be omitted, and new components will be described in detail with the new reference numerals.

As shown in FIG. 3, the pin-shaped load cell 50 according to the present invention includes a shaft portion 51 having a predetermined length and forming a pin shape, and couplings formed at both ends of the shaft portion 51, respectively. It consists of the support portion 54, 55 between the portion 52, 53, and the coupling portion 52, 53 and protruded and formed at intervals,

The shaft portion 51 has a diameter that is relatively smaller than the supports 54, 55 and the coupling portion 52, 53 while being between the supports 54, 55 and the coupling portion 52, 53. It consists of three attachment parts 56, 57, 58 which have space parts 56a, 57a, 58a formed according to this.

Here, in the present invention, the strain gauge is attached to the circumferential surface of each of the attachment portions 56, 57, 58, the arrangement structure can be different.

That is, first, as shown in Fig. 3 or 4, first, each of the strain on the circumferential surface of the attachment portion 56, 57 located on both sides with respect to the attachment portion 58 formed in the middle of the attachment portion, respectively The gauges 60 and 61 (electrical resistance type) are formed at 90 degree intervals from each other.

In other words, as shown in FIG. 4, the upper positions of the attachment parts 56 and 57 are set to 0 degrees, and are arranged at 90 degree intervals based on this.

3 and 5, extension portions 52a and 53a are formed in the lateral direction of the coupling portions 52 and 53, respectively, and coupling holes (a) are formed in one extension portion 52a. 52b) is formed and fastened to the fastening member 23 through the connecting pipe 22 extending laterally from the bracket 21 of the bucket 20, and is fixed.

The strain gage 60 and the strain gage 61 in this embodiment can be provided in two types.

As a first embodiment, as shown in Figs. 6A and 6B, the strain gauges 60 are the first strain gauge pieces 60A, 60B and the second strain gauge pieces 60C, 60D facing in close proximity to each other. The strain gage 61 is also composed of a first strain gage piece 61A, 61B and a second strain gage piece 61C, 61D facing each other in close proximity to each other. 60A, 60B, 61A, 61B and the second strain gauge piece 60C, 60D, 61C, 61D are each a unit and each other along the circumferential surface of the attachment portions 56, 57. It is placed at 90 degree intervals. However, the present invention is not limited thereto and may be arranged at intervals of less than 180 degrees.

Further, as another embodiment, as shown in Figs. 7, 8A, and 8B, the strain gauges 60, 61 are arranged at 90 degree intervals from each other on the circumferential surface of each attachment portion 56, 57, respectively. However, the strain gauges 60 are two pairs of first strain gauge pieces 60E, 60F, 60G, 60H and second strain gauge pieces 60I, 60J, which face each other at 90 ° intervals. 60K) (60L) is arranged and configured.

Similarly, the strain gage 61 of the second example also has two pairs of the first strain gage pieces 61E, 61F, 61G, 61H and the second strain gage piece 61I and 61J facing each other at 90 ° intervals. (61K) and 61L are arranged and configured.

Here, the strain gauges 60 and 61 having two pairs of first and second strain gauge pieces facing each other shown in FIGS. 8A and 8B are preferably arranged at intervals of 90 degrees, but are not limited thereto. It can be spaced at a maximum of less than 180 degrees.

In addition, the two pairs of first and second strain gauge pieces are preferably arranged radially at intervals of 90 degrees from each other.

In other words, two pairs of the first strain gage pieces 60E, 60F, 60G, 60H are individually arranged (similar to the X-shape) at 90-degree intervals. 2nd strain gauge piece 60I, 60J, 60K, 60L, and 1st strain gauge 61E, 61F, 61G, 61H and 2nd strain gauge piece which comprise the strain gauge 61 ( 61I) 61J, 61K, and 61L also have four strain gauge pieces radially arranged at intervals of 90 degrees.

On the other hand, as shown in Figs. 9 to 10B, as a second, by changing the formation position of the strain gauge, the strain gauge 62 can be formed only in the attachment portion 58 located in the middle of the attachment portion.

Strain gauges 62 formed only on the circumferential surface of the attachment portion 58 located in the center of the shaft portion 51 of the pin-shaped load cell 50, the first strain gauge pieces are formed in close proximity to each other in the pair described in the above embodiment It has the same structure and arrangement as (60A) (60B) and the second strain gauge piece (60C) (60D).

Specifically, as shown in FIGS. 10A and 10B, the first strain gage pieces 62A and 62B and the second strain gage pieces 62C and 62D, which constitute the strain gage 62, are each other. It is a structure that is arranged in a pair facing each other and parallel to the shaft portion 51 while being close.

In other words, the first strain gage piece 62A and the first strain gage piece 62B are disposed to face each other while being in close proximity to each other, and are arranged parallel to the shaft portion 51, and the second strain gage piece 62C and the first strain gage piece 62C are disposed. The same applies to the two strain gauge pieces 62D.

Further, the strain gauges 62 formed on the circumferential surface of the attachment portion 58 are arranged at intervals, but are preferably arranged at intervals of 90 degrees, but are not limited thereto and may be disposed at a maximum of less than 180 degrees. .

In the case where the strain gauge is formed on the attachment portions 56 and 57, the size and direction of the eccentric load, which is the asymmetrical load on the left and right sides, are measured and calculated. However, the strain gauge 62 formed on the attachment portion 58 As a structure that can be calculated by measuring only the magnitude (bending moment measurement) of the total load transmitted through the pin-shaped load cell 50, it forms the simplest structure.

Moreover, in the embodiment of the present invention, strain gauges are shown but in practice strain gauges having a very small size are applied.

In other words, each of the first and second strain gauge pieces is preferably smaller in size, and as the first and second strain gauge pieces are closer to each other, the magnitude and direction of the load can be accurately measured.

On the other hand, the pin-shaped load cell 50 according to the present invention can be applied to various construction machinery, as an example, it can be applied to an excavator.

More specifically, when the pin-shaped load cell 50 is inserted when the arm 10 constituting the excavator 1 and the bucket 20 are inserted, two bearings 11 and 12 are respectively provided to the pin-shaped load cell. Protruding of the 50, it is made to smoothly rotate while contacting the formed support (54, 55).

Strain gauges 60 and 61 of the pin-shaped load cell 50 are sealed for safety, and a measurement line (not shown) is connected to both ends of the pin-shaped load cell 50 to be connected.

In addition, a protective tube (not shown) for protecting the measurement line may be provided at the coupling portions 52 and 53 which are both ends of the pin-shaped load cell 50 to prevent damage to the measurement line during the operation.

As shown in FIG. 5, when the pin-shaped load cell 50 is coupled to the excavator 1, the support parts 54 and 55 protruded and formed at intervals on the shaft portion 51 of the pin-shaped load cell 50. The strain gauges 60, 61, 62 can pass through the arm 10 and the bucket 20 and remain intact without interference. In other words, since the spaces are maintained by the space portions 56a, 57a, 58a, the strain gauges 60, 61, 62 are not damaged and the attachment state can be maintained as it is.

The pin-type load cell 50 measures the magnitude and direction of the load using an internally configured bridge circuit for the electric signal output during the operation of the excavator (1). Since the measurement of the magnitude and direction of such a load is a known technique that can be calculated by engineering theory and principle, detailed description thereof will be omitted.

In addition, the arrangement of the first strain gage pieces and the second strain gage pieces at intervals of 90 degrees has described the most preferable arrangement interval, and the present invention is not limited thereto, and is arranged at different angles (for example, at intervals of 60 degrees). Similar in terms of engineering theory.

In addition to the combination of the pin-shaped load cell 50 according to the present invention instead of the pin 41 used when connecting the arm 10 and the bucket 20, as shown in the accompanying drawings, Figure 1, Instead of the pin 40 used at the time of connecting the link member 32 and the bucket 20 among the link members connected to the arm 10 and the hydraulic cylinder 30, it is rotatable with a pin-shaped load cell 50 according to the present invention. It has a structure that is combined easily.

In addition, the pin-shaped load cell 50 according to the present invention may be used instead of the pins 42 and 43 and 44 coupled to the upper end of the arm 10.

Furthermore, in the present invention, the pin-shaped load cell 50 is connected to the monitor so that the user can grasp the change state (size and direction) of the load in real time.

The present invention having such a configuration, when the arm 10 and the bucket 20 of the excavator (1) as shown in Figure 5, or the link members 31 and 32 connected to the hydraulic cylinder 30 and When the arm 10 and the bucket 20 are coupled, or when the upper end of the arm 10 is coupled, the pin-shaped load cell 50 is used in combination. When working at various construction sites, the hydraulic cylinder 30 is operated. Work while rotating the bucket 20 freely.

At this time, strain gauges (60, 61, 62) are provided on the circumferential surface of the attachment portion (56) (57) or the attachment portion (58) while being the shaft portion (51) of the pin-shaped load cell (50). You can measure the magnitude and direction of the load in real time.

In other words, the shear load transmitted to the pin-shaped load cell 50 by the operation of the hydraulic cylinder 30 is accurately measured in various directions.

In the case where the strain gauges 60 and 61 are formed at the two attachment portions 56 and 57 at the pin-shaped load cell 50, the load eccentrically to one side during the operation of the excavator 1 If an asymmetric load occurs, it can be identified immediately, and appropriate measures can be taken accordingly.

In other words, the strain gauges 60 and 61 separately measure loads applied from the left and right sides, and calculate moments due to asymmetrical loads transmitted through the pin-shaped load cell 50.

In addition, when the eccentric load is not recognized in real time during the operation, the eccentric load acts as various defects on the coupling site during the operation, and as a result, it may cause damage and malfunction of the machine and safety accidents. Therefore, it is possible to immediately grasp this in real time and cope with it.

In addition, the root cause of the eccentric load can be grasped and used as data data for more reliable excavator manufacturing.

In addition, when the strain gauge 62 is formed in the attachment part 58 which is located in the center of the attachment part of the pin-shaped load cell 50, the magnitude | size of the total load which arises during the operation of the excavator 1 can be measured.

As described above, the present invention can accurately measure the load in various directions, so that the worker can easily measure or monitor the load on the work during the operation, and thus prevent the excessive load work.

Moreover, the present invention can accurately calculate the load generated during the operation of the excavator, and thus, the optimum excavator can be manufactured during the manufacture of the excavator.

Although the present invention has been described with respect to an excavator, the present invention is not limited thereto and may be applied to connection parts of various construction machines (eg, wheel loaders, forklifts, cranes, etc.).

Although the present invention has been described for the embodiments of the present invention based on the accompanying drawings for convenience, it is obvious that various modifications and changes are possible within the scope of the technical idea of the present invention.

1 is a view showing a state of a conventional general construction machinery excavator.

2 is an exploded perspective view schematically illustrating a connection structure of a bucket and an arm of a conventional excavator.

3 is a perspective view showing a pin-shaped load cell according to an embodiment of the present invention.

4 is a cross-sectional view taken along line A-A and line B-B of FIG. 3.

5 is a cross-sectional view showing a pin-shaped load cell coupled to an excavator according to an embodiment of the present invention.

6A is an enlarged view of a portion C of FIG. 4.

6B is an enlarged view of a portion D in FIG. 4.

7 is a perspective view showing a pin-shaped load cell according to another embodiment of the present invention.

FIG. 8A is an enlarged view of a strain gauge formed in a pin type load cell according to another exemplary embodiment of the present invention as viewed in the direction of part C of FIG. 4.

FIG. 8B is an enlarged view of a strain gauge formed in a pin type load cell according to another embodiment of the present invention as viewed in the direction of part D of FIG. 4.

9 is a perspective view showing a pin-shaped load cell according to another embodiment of the present invention.

FIG. 10A is an enlarged view illustrating an example of a strain gauge formed in an attachment portion of the pin-shaped load cell of FIG. 9.

FIG. 10B is an enlarged view illustrating a strain gauge formed at intervals of 90 degrees in FIG. 10A.

[Code Description in Drawings]

1: excavator

2: boom

3: hydraulic cylinder

10: arm

20: bucket

21: bracket

22: connector

23: fastening member

30: hydraulic cylinder

31,32: link member

40,41,42,43,44: Coupling Pin

50: pin type load cell

51: shaft portion

52,53: coupling part

52a, 53a: extension part

54,55 support part

56,57,58: attachment

56a, 57a, 58a: space part

60,61,62: Strain Gauge

60A, 60B, 61A, 61B, 60E, 60F, 60G, 60H, 61E, 61F, 61G, 61H, 62A, 62B: 1st strain gauge

60C, 60D, 61C, 61D, 60I, 60J, 60K, 60L, 61I, 61J, 61K, 61L, 62C, 62D: Second strain gauge

Claims (8)

A shaft forming a pin shape; A pair of supports protruding and formed at intervals on the shaft portion; It is formed on the side of each support portion, formed of a diameter smaller than each support portion consists of one or more attachment portion having a space portion, A load gauge pin-type load cell, characterized in that a strain gauge is formed on at least one attachment part circumferential surface. The method according to claim 1, Strain gauges formed on each circumferential surface of the attachment portions positioned at both sides at intervals of the attachment portions to measure asymmetrical loads, each of the first and second strain gauge pieces adjacent to each other in parallel and parallel to each other Pin-shaped load cell for load measurement, characterized in that arranged in the. The method according to claim 1, Strain gages formed on each circumferential surface of the attachment portions positioned at both sides at intervals of the attachment portions to measure an asymmetrical load are arranged by two pairs of first strain gauge pieces and second strain gauge pieces facing each other. Pin type load cell for load measurement, characterized in that. The method according to claim 1, Strain gauges formed on the circumferential surface of the attachment portion located in one of the attachment portions are arranged in a pair of adjacent first strain gauge pieces and second strain gauge pieces, respectively. The method according to any one of claims 2 to 4, The first strain gage piece and the second strain gage piece constituting the strain gauge are pin-shaped load cell for load measurement, characterized in that disposed at less than 180 degrees with an angle to have a distance from each other. The method of claim 3, The first strain gage piece and the second strain gage piece are each individually arranged to form two pairs at intervals of 90 degrees to each other pin-shaped load cell, characterized in that. In an excavator comprising a bucket, an arm and a link member connected to the bucket, An excavator provided with a pin-shaped load cell for load measurement, wherein the bucket and the arm are coupled to the pin-shaped load cell for load measurement according to any one of claims 1 to 6. In an excavator comprising a bucket, an arm and a link member connected to the bucket, An excavator having a load measuring pin-type load cell, wherein the bucket and the link member are coupled to the load measuring pin-type load cell according to any one of claims 1 to 6.

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