JPS6045119B2 - Mobile crane rotation angle detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mobile crane rotation angle detection device for detecting a rotation angle when a crane body of a truck crane or the like faces forward of a carrier.

Generally, as shown in Fig. 1, a mobile crane includes a carrier 1, a crane body 2 rotatably attached to the carrier, and a boom 3. During crane work, the mobile crane is lifted by a front outrigger 4 and a rear outrigger 5. Supported.

During crane work, as shown in Figure 2, the area between 4 and 8 and C around the center of rotation of the crane body 2 is defined as the forward lifting area, which is distinguished from the side and rear lifting areas up to C-O-4. . In other words, the engine of the carrier 1 (not shown) is located at the front of the carrier 1, and the carrier frame also extends beyond the position of the outrigger 4 at the front, making the crane unstable. When the carrier 1 turns to the front lifting range with a lifting load of be. To prevent this, the lifting capacity of the front lifting area is set lower than that of the side and rear lifting areas. Therefore, in the mobile crane 7, a turning angle detection device for detecting the front lifting range is essential. Conventional swing angle detection devices are equipped with a cam and a detection switch that detect the forward lifting range and generate a signal, and when the crane body is located within the forward lifting range, an alarm or indicator light is activated so that the operator can I was trying not to lift an overload.

Next, a conventional turning angle detection device will be explained with reference to FIGS. 3 to 9.

What is shown in FIG. 3, FIG. 4, and FIG.
A cam 6 having a cam surface with a detection angle θ set to detect the turning angle of the crane main body 2 corresponding to the forward lifting range extending over C is fixed, and a cam surface with a radius R from the turning center 0 is fixed on the crane main body 2 side. A microswitch 7 is provided so that it can move on a circular locus.

When the crane main body 2 is rotated counterclockwise in FIG. 4, one operating position 6 of the detection angle θ
At step a, the detection roller 8 of the micro switch 7 is pushed up and operated, and then the detection roller 8 follows the rotation of the crane body 2 while contacting the force surface, and moves along a circular trajectory with a radius R to the other operating position 6c. The crane body 2 moves and the detection angle is detected, and the turning angle of the crane body 2 is detected. Further, when the crane main body 2 is rotated in the clockwise direction in FIG. The turning angle is detected by moving from the position 6a to the operating position 6a. However, as can be understood from FIG. 5, in this conventional device, the cam surface of the cam 6 is inclined due to the inclination due to machining distortion of the mounting surface on the carrier 1 side to which the cam 6 is attached. To! A narrower angle 0a or a wider angle 0b
Therefore, there is a drawback that a large error occurs in the detected turning angle.

By the way, when working with a crane, it is necessary to set a plurality of detection angles in order to change the forward lifting range depending on the size of the lifting load, and to set a large angle for a large weight and a small angle for a small load.

6 and 7 show a conventional device in which the technique shown in FIGS. 3 to 5 is applied to change the above-mentioned front suspension range. In this device bow, the detection angle is set on the carrier side. In descending order of magnitude, a cam 63 with a detection angle θ3, a cam 62 with a detection angle θ2, and a cam 61 with a detection angle θ1 are superimposed and attached in a stepped manner, and on the crane body side, a circular trajectory with a radius R3 is formed in order of a circular trajectory with a large radius. A microswitch 73 having a detection roller 83 on top, a microswitch 72 having a detection roller 82 on a circular locus with radius R2, and a microswitch 7 having a detection roller 81 on a circular locus with radius R1.
1 is attached to each.

Then, the detection angle θ3 is detected by the combination of the cam 63 and the detection roller 83 of the microswitch 73, and the cam 62
The detection angle 02 is detected by the combination of the detection roller 9 and roller 82 of the microswitch 72, the detection angle 01 is detected by the combination of the cam 61 and the detection roller 81 of the microswitch 71, and the rotation angle of the crane main body 2 is detected in each case. It is becoming more and more common.

7 However, the conventional device shown in FIGS. 6 and 7 not only has a large error in the detected angle like the devices shown in FIGS. 3 to 5 described above, but also has Depending on the number of sets, it is necessary to provide a large and high space for mounting these members, which has the drawback of increasing the size of the detection device.

Furthermore, there has been proposed a turning angle detection device in which a cam surface is formed on the outer end surface of a cam, and a microswitch is horizontally attached to the cam surface in correspondence with the cam surface. 8 and 9 show a conventional device in which the above-mentioned technique is applied to the lifting range for changing the front suspension range. On the carrier 1 side, in descending order of the detection angle, there is a cam 93 with a detection angle θ3, a cam 93 with a detection angle θ3, A cam 92 having an angle of θ2 and a cam 91 having a detection angle of θ1 are stacked and attached in a stepped manner in the circumferential direction.

On the other hand, each of the cams 93, 92, 91 is provided on the crane main body 2 side.
A detection roller 8 that can come into contact with a cam ring formed on the outer end surface of the
microswitches 73, 72, with 3, 82, 81;
71 are each mounted horizontally.
In this device, as the microswitches 73, 72, and 71 turn following the turning movement of the crane main body 2,
The detection rollers 83, 82, 8 are attached to the cams 93, 92, 91.
1 comes into contact with the detection angle θ3, 02, θ
1 one after another'. The rotation angle of the crane main body 2 is detected. But this 8th
The conventional device shown in FIGS. 9 and 9 also requires a large space for mounting the entire detection device including the cam and the microswitch, at least in the height direction, and has the disadvantage of inevitably increasing in size.

An object of the present invention is to accurately detect the turning angle of the crane body even when the cam surface is tilted with respect to the horizontal plane due to stress on the mounting surface of the cam, and to set a plurality of detection angles. Even if it is single. It is an object of the present invention to provide a swing angle detection device for a mobile crane that requires the same installation space as in the case of the mobile crane. An object of the present invention is to provide a turning angle detection device. The present invention provides a mobile crane in which the crane itself is rotatably mounted on a carrier, and a set of two cranes mounted on either the carrier part or the crane body at the pivot center of the crane body. cams are provided, and a set of at least two detection switches are provided on the other side of the crane main body or the carrier part, and each set of the two cams has its operation start position located within the forward lifting range of the crane main body. The two detection switches are arranged so as to align with the center line of the crane body and extend in opposite directions from the operation start position, and the two detection switches The angle of the front lifting range of the crane body is set apart so that the center between each set of detection switches coincides with the operation start position of the set of two cams, and the cam and the detection switch are , the other cam and the other detection switch are configured to be in a disengaged state when the one detection switch starts to engage with the operation start position of the one cam, and the one cam and the one detection switch are in a disengaged state. Detection starts when the other cam is engaged with the other detection switch, and detection ends when the other cam and the other detection switch are disengaged. It is characterized by generating a signal corresponding to a low allowable load.

The present invention will be explained below based on the drawings.

10, 11, and 12 show an embodiment of the present invention, which includes a set of two cams 101, 102 and a set of two microswitches 111, 112. .

Among the pair of cams 101 and 102, the single-force cam 101 is located on a circular locus with a radius RlOl from the rotation center 0 of the crane main body (not shown) on the upper surface, at least at a detection angle of 0, 112 or more, and less than a detection angle θ. The cam surface 103 is formed in a substantially fan shape with a cam surface 103 having a width of .
A slope is formed at one end of the crane, and the slope is the actuation start position 105 of the microswitch 111 when the crane body turns clockwise in FIG.

The other cam 102 has a cam surface 104 on a circular locus with a radius RlO2 larger than the radius RlOl from the rotation center 0 on the upper surface, and has a cam surface 104 having a range of at least 112 or more of the detection angle θ and less than the detection angle θ. The cam surface 104 is formed into a fan shape, and a slope is formed at one end of the cam surface 104, and the slope is located at the actuation start position 106 of the microswitch 112 when the crane main body turns counterclockwise in FIG.
It is said that

Note that the detection angle 0 is arbitrarily set in accordance with the forward hanging range of the crane.

The cams 101 and 102 are fixed on the carrier 1 with a common mounting bolt 130, with respective operation start positions 105 and 106 aligned with a straight line extending in the radial direction from the rotation center 0 and overlapped in the upper and lower directions. , preferably with the operation start positions 105 and 106 aligned with the center line of the front suspension range.

The microswitches 111 and 112 adjust the detection angle θ
The cam surfaces 103,
104 and the detection rollers 121 and 122 are mounted vertically on the crane body, facing each other, and when one or both of the detection switches is activated, the allowable load is lower than the allowable load of the side and rear lifting ranges. (generates a signal indicating this).

In the swing angle detection device configured as described above, when the crane main body located at the side/rear position is rotated counterclockwise (to the front position of the carrier) and the reference position of the crane main body has turned to position 8 in FIG. As shown in FIG. 11(1), the detection roller 122 of the microswitch 112 is pushed up and activated at the operation start position 106 of the cam 102, and detection of the turning angle is started. 111 is separated from the cam 101 and is inactive.

Further, in the process of the crane body turning counterclockwise and moving to the 8th position, as shown in FIG. also works.

Meanwhile, the detection of the turning angle continues. Next, the crane body turns counterclockwise, and its reference position is C.
When passing the position, the detection roller 122 of the microswitch 112 comes off the cam surface 104 of the cam 102 and becomes inactive, as shown in FIG. 11 (Iiii). At this point, the detection angle θ is detected and the crane The rotation angle of the main body is detected.

On the other hand, the crane body located at the side/rear position is rotated clockwise (
When the carrier is rotated to the front position), cam 1
01, 102 and the microswitches 111, 112 act relatively opposite to those described above, the set detection angle θ can be detected in this case as well, and the rotation angle of the crane body can be detected. . Even if the crane is tilted with respect to the horizontal plane and the cams 101 and 102 are accordingly tilted as shown by the imaginary lines in FIG. Since 105 and 106 do not change, the detection angle θ can be accurately detected and the turning angle can be detected. Therefore, in the above-mentioned operation process, the cam surfaces 1 of the cams 101 and 102
Since 03 and 104 have a width that is half the detection angle θ, the cam surfaces 103 and 10 are distorted due to machining distortion of the cam mounting surface.
Even if 4 is tilted, the contact between the microswitch and the cam surface will not be broken. Therefore, when the crane main body 1 is located in the front suspension range, it is possible to always generate a signal corresponding to an allowable load lower than the allowable loads in the side and rear suspension ranges. FIG. 13 shows an application example of FIG. 10, in which the cam surface 1 on the circular locus of radius RlOl on the upper surface of the cam 101
The detection roller 123 of the microswitch is placed opposite to 03.
, 125, 127 are provided and face the cam surface 104 on the circular locus of radius RlO2 on the upper surface of the cam 10-2. Detection rollers 124, 126, and 128 of microswitches are also provided.

The detection rollers 123 and 124 are set as one set to detect a minimum detection angle θ1 arbitrarily set depending on the magnitude of the lifting load of the crane, and the detection rollers 125 and 126 are set as one set to detect an intermediate detection angle 02. , the detection roller 127
, 128 are constructed in the same manner as in the embodiment shown in FIGS. 10 to 12, except that they are arranged as one set to detect the maximum detection angle θ3.

In the turning angle detecting device of this embodiment, as the crane main body is turned counterclockwise and clockwise in FIG.
3,124, the detection rollers 125, 126, and the detection rollers 127, 128, the arbitrarily set detection angles θ1, θ2, and θ3 are sequentially detected. The turning angle can be detected accurately.

Also, the angle θ is the sum of the cams 101 and 102.

The relationship between and the maximum detection angle θ3 is θ3≦θ. Any number of detection angles can be set within the range of . Moreover, when setting these multiple detection angles, even if
The same mounting space as the single coupling shown in the figure is sufficient.

In both the embodiments shown in FIGS. 10 to 12 and the embodiment shown in FIG. 13, the cams 101 and 102 may be mounted on the crane body side, and the micro switch may be mounted on the carrier side.

14 and 15 show another embodiment of the invention, which includes a set of two cams 141, 142 and a set of two microswitches 151-156.

The cams 141, 142 are attached to the crane main body (not shown)
cam surfaces 143 and 144 each having a width of at least 112 or more of the detection angle θ and less than 0 of the detection angle are formed on the outer peripheral end surface on the same radius from the rotation center 0 of the cam surface. A slope is formed at one end of the cam surface 143, and the slope of the cam surface 143 is the slope of the eye cross switch 1 when the crane body turns clockwise in FIG.
51, 153, 155, and the slope of the cam surface 144 is the actuation start position 146 of the microswitches 152, 154, 156 when the crane body turns counterclockwise.

Further, the cam surfaces 141 and 142 align the operation start positions 145 and 146 on a straight line extending radially from the rotation center 0, overlap each other in the vertical direction, and move to either the carrier side or the crane main body side. installed.

Among the microswitches 151, 156, the microswitches 151, 153, 155 are connected to the detection roller 161,
163 and 165 are arranged facing the cam surface 143,
The other microswitches 152, 154, 156 are arranged with detection rollers 162, 164, 166 facing the cam surface 144.

The microswitches 151 and 152 are provided as a pair with an interval matching an arbitrarily set minimum detection angle 01, and the microswitches 153 and 154 are provided with an interval matching an intermediate detection angle 02. The microswitches 155 and 156 have a maximum detection angle θ.
3, and these microswitches 151 to 156 are installed horizontally on either the carrier side or the crane body side.

In addition, the detection roller 16 of the microswitches 151 to 156
1 to 166 are urged to protrude as shown by the imaginary lines in FIG. 14, and the microswitches are inactive in the protruding state. In the swing angle detection device configured as described above, the crane body located at the side/rear position is rotated counterclockwise in FIG.
When the carrier is rotated to the forward position of the carrier and its reference position reaches position 4, the detection roller 166 of the microswitch 156 is pushed by the cam surface 144 at the operation start position 146 of the cam 142, and the microswitch 156 is activated. Detection of the maximum detection angle θ3 is started, and as the crane body passes through the third position, the microswitches 154 and 152 pass through the operation start position 146 one after another to detect the intermediate detection angle θ2 and the minimum detection angle θ1. was started,
Next, as shown in FIGS. 14 and 15, the microswitches 151, 153, and 155 are sequentially activated by the cam surface 143 of the cam 141 toward the 8th position.

Further toward the C position, the micro switch 156,1
54 and 152 are removed from the cam surface 144 of the cam 142 in this order. When the crane body is further rotated counterclockwise and moved to position C, microswitches 151, 153, 15 are activated.
5 is removed from the cam surface 143 of the cam 141 in the order of 5, whereby the minimum detection angle θ1, the intermediate detection angle θ2, and the maximum detection angle θ3 are detected one after another, and the turning angle of the crane body is detected. Also, when the crane body is rotated in the clockwise direction (the forward position of the carrier) at the side or rear position, the cams 142, 142 and the microswitches 151 to 156 act in a relatively opposite manner, but this is the same as described above. As a result, the minimum detection angle θ1, the intermediate detection angle θ2, and the maximum detection angle θ3 can be detected, and the turning angle of the crane body can be detected. In the invention shown in FIGS. 14 and 15, it is of course possible to detect a single detection angle by providing only one set of microswitches. Face 14
3,144 may be formed on different radii.
This invention can also be accommodated in the same mounting space as when detecting a single detection angle. As explained above, according to the present invention, the turning angle can be accurately detected regardless of the processing distortion of the carrier to which the cam is attached or the mounting surface of the crane body.

Furthermore, even when setting a plurality of detection angles, the same mounting space as in the case of a single detection angle is sufficient, and therefore the entire device can be made compact. Furthermore, as shown in FIGS. 14 and 15, if the cam surfaces are formed on a circular arc trajectory and on the same radius from the center of rotation, the above-mentioned effects can of course be achieved. Furthermore, 2
A set of cams can be manufactured with the same shape.
Therefore, the productivity of the cam can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a side view of the mobile crane in its working state, Fig. 2 is a plan view of the same, and Fig. 3 is an enlarged sectional view of the part ■ in Fig. 1, which is a side view of a conventional swing angle detection device. , Fig. 4 is an enlarged plan view of the same, Fig. 5 is a front view of Fig. 4, Fig. 6 is a plan view of another example of the conventional device, Fig. 7 is a side view of the same, and Fig. 8 is a diagram of the conventional device. A plan view of another example, FIG. 9 is a side view of the same. 1-0 is a plan view of an embodiment of the present invention, and FIG. 11 (
1), (1i), and (Iiii) are explanatory diagrams of the working state seen from the side, FIG. 12 is an explanatory diagram of the working state seen from the front, FIG. 13 is a plan view of another embodiment, and FIG. 14 is an explanatory diagram of the working state seen from the front. FIG. 15 is a front view of the invention. θO...Turning center of the crane body, 101, 102...Cam, 10
3,104...Cam surface, 105,106...Operation start position, 111,112...Micro switch, 121
, 122... detection roller, 123-128... detection roller, 141, 142... cam, 143, 144...
...Cam surface, 145, 146...Operation start position, 151
~156...Micro switch, 161~166...
・Detection roller.

Claims (1)

[Claims] 1. In a mobile crane in which the crane itself is rotatably mounted on a carrier, a set of two cams centered at the center of rotation of the crane body is installed on either the carrier part or the crane body at the center of rotation of the crane body. At the same time, a set of at least two detection switches is provided on the other side of the crane main body or the carrier part, and
The set of cams are arranged so that their respective operation start positions coincide with the center line of the front suspension range of the crane body and extend in opposite directions from the operation start positions, and
Set the detection switches so that when the crane body is located at the center line of the forward hanging range of the carrier part, the center between the two detection switches coincides with the operation start position of the two cams. The cam and the detection switch are arranged such that the angle of the front suspension range of the crane body is separated, and the cam and the detection switch are connected to each other at a position where one detection switch starts to engage with the operation start position of one cam. The detection switch is configured to be in a disconnected state from the detection switch, and detection is started by engagement of the one cam with the one detection switch, and detection is ended by disengagement of the other cam and the other detection switch. A turning angle detection device for a mobile crane, characterized in that when the crane body is located in the front lifting range, a signal corresponding to an allowable load lower than the allowable load in the rear and side lifting ranges is generated.