JP2749781B2 - Turning position detector for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning position detecting device for a construction machine such as a hydraulic excavator, and more particularly to a turning position detecting device for determining a relative position between an upper revolving unit and a lower traveling unit. is there.

[0002]

2. Description of the Related Art Conventionally, in a construction machine of this type, an upper swing body is formed so as to be swingable with respect to a lower traveling body. Therefore, when the operator is sitting on the cockpit provided on the upper revolving structure and performing the work while revolving the upper revolving structure, there is a risk that the relative position of the upper revolving structure with respect to the lower traveling structure may be lost, and the progress of the aircraft may be lost. There is a danger of misjudging the direction and causing an accident.

Therefore, in order to prevent such erroneous running operation, a potentiometer is incorporated in the rotary joint, the position of the running motor is displayed in the cockpit by detecting the rotation angle of the upper swing body, and the upper swing is displayed to the operator. Means for recognizing the relative position of the body with respect to the undercarriage are known.

[0004]

As described above, since the conventional turning position detecting device incorporates a potentiometer in a rotary joint, it not only leads to a significant increase in cost, but also makes assembly work difficult. There is also a problem in the durability of the device.

[0005] In view of the above, the turning position detecting device has a simpler structure to reduce the cost, and technical problems to be solved in order to improve the durability of the device arise. The purpose is to solve.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object, and is intended for a construction machine in which an upper revolving unit is mounted on a lower traveling unit via a rotary joint. A hollow cylindrical cam surrounding the rotary joint rotor is fixedly mounted on the lower traveling body along the outer circumference of the rotary joint rotor which is fixed to the body and rotates, and the upper and lower stages of the cam are respectively directed forward. The outer diameter is different for each of the two regions of the region, the rearward region, the leftward region, and the rightward region, and the lower part of the cam is one of the two regions having the larger outer diameter of the upper part. The outer diameter of only one of the two regions where the outer diameter of the upper stage is smaller is formed larger, and the outer diameter of only one of the two regions is smaller. In addition to being fixed, the two position sensors are moved along the upper side surface and the lower side surface of the cam, respectively, so that the two position sensors are turned on and off, thereby turning the turning position of the upper turning body. An object of the present invention is to provide a construction machine turning position detection device for determining.

[0007]

When the upper revolving unit is swung, the two position sensors move along the upper side surface and the lower side surface of the hollow cylindrical cam, respectively. Turn ON and 0FF respectively.

The outer diameters of the upper and lower cams are combined into four types, large and large, large and small, small and large, and small and small, for each of the four regions. Two position sensors are ON and ON, ON and 0FF, 0FF and ON, 0FF and 0F for every four areas
Four switching states of F are formed.

Thus, it is possible to determine from the switching state whether the upper revolving superstructure is located in the forward region, the backward region, the leftward region or the rightward region.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. In FIG. 1, reference numeral 1 denotes a hollow cylindrical cam, which is fixed to a lower traveling body 4 via a rotary joint housing 3 while surrounding a rotary joint rotor 2. As shown in FIGS. 3 and 4, the outer diameter of the cam 1 is small in both the upper and lower stages in the forward region a, large in both the upper and lower stages in the rearward region b, and large in the upper region in the leftward region c. The lower part is small, and the upper part is small and the lower part is large in the rightward region d.

Further, the rotary joint rotor 2
Two limit switches 7 and 8 are fixedly mounted as position sensors on the upper revolving structure 5 via a bracket 6, and the terminals of the limit switches 7 engage the upper side surface of the cam 1, and The terminal is engaged with the lower side surface of the cam 1. When each of the limit switches 7 and 8 is in contact with a region having a large outer diameter of the cam 1, the terminal is pressed and turned ON, while when the terminal is in contact with a small region, the terminal is released. Is set to 0FF.

When the revolving position of the upper revolving unit 5 with respect to the lower traveling unit 4 is in the forward area a, both of the two limit switches 7 and 8 have the outer diameter of the cam 1 as shown in FIG. Is in contact with the small area of
It has become. When the upper revolving unit 5 rotates counterclockwise with respect to the lower traveling unit 4, the terminals of the limit switches 7 and 8 slide along the upper side surface and the lower side surface of the cam 1, respectively. When the body 5 enters the leftward area c, as shown in FIG. 6, the limit switch 8 is still in contact with the area where the outer diameter of the lower part of the cam 1 is small, and remains at 0FF. The terminal is pressed by being mounted on a region having a large outer diameter, and is turned ON.

Further, when the upper swing body 5 rotates counterclockwise and enters the rearward area b, as shown in FIG. 7, the limit switch 8 also rides over the area where the cam 1 has a large lower outer diameter. The two limit switches 7, 8 are both
Becomes ON state. Further, when the upper swing body 5 rotates counterclockwise and enters the rightward region d, as shown in FIG. 8, the limit switch 7 enters the region where the outer diameter of the upper stage of the cam 1 is small, and the pressing of the terminal is released. As a result, the switch is switched to 0FF, while the limit switch 8 remains in the area where the lower outer diameter of the cam 1 is large.

Thus, the upper revolving unit 5 is moved to any one of the forward region a, the backward region b, the left region c, and the right region d by the mutual switching state of the two limit switches 7 and 8. It can be determined whether it is located. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0015]

As described in detail in the above-mentioned embodiment, the present invention is configured so that the turning position of the upper turning body can be easily detected by the hollow cylindrical cam and the two position sensors. Therefore, as compared with the conventional means for incorporating a potentiometer, not only can a significant cost reduction be realized, but also the assembly operation becomes extremely easy.

Further, the present invention has various effects, such as excellent durability because the mechanical cam mechanism is used, and easy maintenance and repair.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view of FIG.

FIG. 3 is an end view taken along line AA of the cam in FIG. 2;

FIG. 4 is an end view of the cam taken along line BB in FIG. 2;

FIG. 5 (a) is a partially cutaway side view showing the engaged state of the cam and two limit switches when the upper revolving unit is in the frontward region, and viewed from the leftward region side. (B) The top view which shows the attitude | position of the lower traveling body and the upper revolving superstructure at that time.

FIG. 6 (a) is a partially cutaway side view showing the engaged state of the cam and two limit switches when the upper swing body is in the leftward area, and viewed from the rearward area side. (B) The top view which shows the attitude | position of the lower traveling body and the upper revolving superstructure at that time.

FIG. 7A is a partially cutaway side view showing the engagement state of a cam and two limit switches when the upper revolving unit is in a rearward region and viewed from a rightward region side. (B) The top view which shows the attitude | position of the lower traveling body and the upper revolving superstructure at that time.

FIG. 8 (a) is a partially cutaway side view showing the engagement state of the cam and two limit switches when the upper revolving unit is in the rightward region, and viewed from the frontward region side. (B) The top view which shows the attitude | position of the lower traveling body and the upper revolving superstructure at that time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow cylindrical cam 2 Rotary joint rotor 4 Lower traveling body 5 Upper revolving body 7, 8 Limit switch

Claims (1)

(57) [Claims] 1. A construction machine in which an upper revolving unit is mounted on a lower traveling unit via a rotary joint, and surrounds the rotary joint rotor along the outer periphery of a rotating rotary joint rotor fixed to the upper revolving unit. A hollow cylindrical cam to be fixed to the lower traveling body, and the outer diameter of the upper and lower tiers of the cam is set in each of two regions of a forward region, a rearward region, a leftward region, and a rightward region, respectively. The lower stage of the cam is formed differently and the outer diameter of only one region of the two regions of the upper stage where the outer diameter is large is formed to be small, and the lower stage of the cam is one of the two regions where the outer diameter of the upper stage is small. The outer diameter of only the region is formed large, and two position sensors are fixed to the upper revolving unit near the rotary joint rotor, and the two position sensors are respectively connected to the upper side surface and the lower side of the cam. A turning position detection device for a construction machine, wherein the turning position of an upper turning body is determined by moving the two position sensors on and off of each other along a plane.