JPH08133680A - Boom position detecting device for crane - Google Patents

Abstract

PURPOSE: To provide a device for detecting mutual position between booms of a crane without adjusting unevenness even in the case where unevenness of boom dimension exists and without performing the wrong operation even in the case where abrasion is generated. CONSTITUTION: One end of a rectangular spring plate 13 is fastened by a screw 14 so as to ride over a hole 4 provided in a first boom 1, and the other end thereof is pinched by a presser plate 15 fastened freely to be moved by a bolt 16. A sliding plate 20 is installed in a central part of the spring plate 13, and a magnetic sensor 22 is installed in a central part of the sliding plate 23. The spring plate 13 is bent so as to push the sliding plate 20 to a second boom 2, and a magnetic body 5 is attached to the second boom 2 at the predetermined position. Even in the case where unevenness is generated in the boom dimension, adjustment is unnecessary, and wrong operation is not performed even in the case where abrasion is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detecting device for detecting a mutual position between booms of a crane having a multi-stage telescopic boom.

[0002]

2. Description of the Related Art In a multi-stage telescopic boom of a crane, generally, two or more hydraulic cylinders are used to extend and retract the second and third booms, respectively, and it is detected that the second boom is fully extended. The telescopic cylinder is being switched.

Conventionally, in detecting the mutual position of the first boom and the second boom, the position detecting device 40 is mounted on the first boom 1 as shown in FIG.
Is detected to have been extended by a predetermined length in the direction of the arrow. In addition, in the figure, the third boom and the subsequent figures are omitted.

FIG. 9 is a detailed view of the position detecting device 40.
A limit switch 43 is fastened by a bolt 44 to a bracket 42 fastened to a seat plate 41 fixedly mounted on the upper surface of the tip portion of the first boom 1. A lever 45 having a ball 46 at its tip is swingably attached to the limit switch 43, and the switch is turned on and off by swinging the lever 45.
To do. The plate 47 is provided at a predetermined position on the upper surface of the second boom 2.
When the second boom 2 is extended by a predetermined length, the plate 47 moves to the position indicated by the chain double-dashed line in the figure and contacts the ball 46, and the lever 45 is swung to turn on the switch.
Then, a signal is sent to a control device (not shown).

[0005]

However, according to the above construction, since the position of the ball in the height direction with respect to the upper surface of the first boom is fixed, if the boom has dimensional variation or waviness, the first boom is not fixed. The distance between the second boom and the second boom varies, and the position of the limit switch needs to be adjusted. That is, it must be adjusted for each boom. Further, if used for a long period of time, the balls or plates may be worn, which may cause malfunction.

The present invention has been made in view of the above problems, and does not require adjustment even if there are variations in the boom size, and a boom position detecting device for a crane that does not cause malfunction even after long-term use. Is intended to provide.

[0007]

In order to achieve the above object, in a boom position detecting device for a crane according to the present invention, a multistage telescopic boom for a crane equipped with a position sensor for detecting a mutual position between booms is provided. It is characterized in that a magnetic sensor is attached to one boom via an elastic body and pressed against the other boom, and a magnetic body detected by the magnetic sensor is provided at a predetermined position of the other boom.

Further, in a multi-stage telescopic boom of a crane equipped with a position sensor for detecting a mutual position between booms,
It is characterized in that a proximity switch is attached to one boom via an elastic body and is pressed against the other boom, and a hole for detection by the proximity switch is provided at a predetermined position of the other boom.

[0009]

With the above-mentioned structure, the magnetic sensor detects the position of the magnetic body when the magnetic body moves, so that the mutual position of the boom can be detected. Further, since the magnetic sensor is pressed against the other boom by the elastic body, adjustment is not necessary even if there is variation in the boom size, and malfunction does not occur even if the contact portion wears.

Further, since the proximity switch detects the position of the hole when it moves, the mutual position of the boom can be detected, and the proximity switch is pressed against the other boom by the elastic body, so that the boom size varies. There is no need for adjustment even if there is, and it does not malfunction even if the contact part wears.

[0011]

Embodiments of a boom position detecting device for a crane according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view of the tip portion of a multi-stage telescopic boom. The first boom 1 having a hollow rectangular cross section has a second boom 2 and a second boom 2.
The third boom 3 is sequentially inserted and fitted. Illustrations after the fourth boom are omitted. The position detection device 10 is attached to the side surface of the first boom.

FIG. 2 is a plan view of the first embodiment of the position detecting device 10, and FIG. 3 is a sectional view taken along the line AA of FIG. A plate 12 having a rectangular hole 11 in the central portion is arranged to match the position of the rectangular hole 4 provided in the first boom 1, and a strip-shaped spring plate 13 is provided on the outer surface of the plate 12 at one end thereof via the plate 12. It is fastened to the boom 1 with bolts 14. The other end of the spring plate 13 is thicker than the pressing plate 15 and the spring plate 13 that are fastened to the first boom 1 via the plate 12 by the bolt 16 as shown in FIG. 5, which is a sectional view taken along line BB of FIG. It is equipped with a shim 15a and is movable in the longitudinal direction. As shown in FIG. 4, which is a cross-sectional view taken along the line CC of FIG. 2, the sliding plate 2 is provided at the center of the spring plate 13.
0 is attached by a bolt 21, and a magnetic sensor 22 is attached at the center thereof. Reference numeral 23 is a wiring.

As shown in FIG. 3, the spring plate 13 is given a certain amount of bending, and the sliding plate 20 is constantly pressed against the second boom 2. When the second boom expands and contracts and the first boom 1 and the second boom 2 move relative to each other, the sliding plate 20 slides on the surface of the second boom 2. A gap is provided between the tip of the magnetic sensor 22 and the second boom 2, the second boom 2 extends, and the magnetic body 5 attached to a predetermined position of the second boom 2 is attached to the magnetic sensor 22. When it reaches the position of, it detects this and sends a signal.

That is, by attaching the magnetic body 5 to the position on the second boom 2 detected by the magnetic sensor 22 mounted on the first boom 1 when the second boom 2 is fully extended, 2 It can be detected that the boom 2 is maximally extended. The sliding plate 20 is constantly urged toward the second boom 2 side by the spring plate 13, and even if there is a dimensional error in the distance between the first boom 1 and the second boom 2 due to component variations or the like, the spring plate 13 bends. Since it is absorbed by the magnetic sensor 22, it is not necessary to adjust the mounting position of the magnetic sensor 22.
Further, even if the sliding portion is worn, there is no risk of malfunction.

FIG. 6 is a sectional view showing a second embodiment of the position detecting device, which is a spring box 3 mounted on the outer surface of the first boom 1.
0 has a sliding plate 31 inserted,
A spring 32 provided in the spring box 30 urges the second boom 2 side. The magnetic sensor 22 is attached to the center of the sliding plate 31. Also, spring 3
Instead of 2, an elastic body such as rubber may be used. The operation and effect are the same as those in the first embodiment, so the description is omitted.

FIG. 7 is a sectional view showing a third embodiment of the position detecting device. A hole 2a is provided in the boom 2 in place of the magnetic body 5 in FIG. 3 which is a sectional view of the first embodiment, and a magnetic sensor is provided. 22
A proximity switch 22a is attached instead of the above, and the other structure is the same as that of the first embodiment. The operation is similar to that of the first embodiment, and when the second boom 2 extends and the hole 2a of the second boom 2 reaches the position of the proximity switch 22a, this is detected and a signal is transmitted.

The proximity switch 22a may be mounted like the magnetic sensor 22 shown in FIG.

[0019]

Since the present invention is configured as described above,
It is not necessary to adjust even if there is an error in the size of the gap between the first boom and the second boom due to variations in parts, etc., and it is possible to obtain a boom position detection device for a crane that does not cause malfunction even if the sliding part wears. To be

[Brief description of drawings]

FIG. 1 is a side view of a first boom tip portion to which a boom position detecting device of the present invention is attached.

FIG. 2 is a plan view of the first embodiment of the boom position detecting device of the present invention.

3 is a front cross-sectional view of the position detection device showing the cross section AA of FIG.

FIG. 4 is a side sectional view showing a CC cross section of FIG. 2;

5 is a side sectional view showing a BB section in FIG. 2. FIG.

FIG. 6 is a front sectional view of a boom position detecting device according to a second embodiment of the present invention.

FIG. 7 is a front sectional view of a boom position detecting device according to a third embodiment of the present invention.

FIG. 8 is a side view of a first boom tip portion to which a conventional boom position detecting device is attached.

FIG. 9 is a detailed view of a conventional boom position detection device.

[Explanation of symbols]

1 ... 1st boom, 2 ... 2nd boom, 5 ... magnetic material,
10 ... Boom position detector, 12 ... Plate, 13
Spring plate, 15 Press plate, 20 Sliding plate, 22 Magnetic sensor, 2a Hole, 22
a ... Proximity switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Abe 1-9 Minamidai, Kawagoe City, Saitama Prefecture Komatsu Meck Co., Ltd. Head Office Factory

Claims (2)

[Claims] 1. In a multi-stage telescopic boom of a crane having a position sensor for detecting a mutual position between booms, a magnetic sensor is attached to one boom via an elastic body and pressed against the other boom, and a predetermined boom of the other boom is provided. A boom position detecting device for a crane, wherein a magnetic body detected by the magnetic sensor is provided at the position. 2. A multi-stage telescopic boom of a crane equipped with a position sensor for detecting a mutual position between booms, wherein a proximity switch is attached to one boom via an elastic body and pressed against the other boom, and the predetermined boom of the other boom is fixed. A boom position detecting device for a crane, characterized in that a hole for detecting with the proximity kit is provided at the position.