JPH0892997A - Revolution position detecting device for construction machine - Google Patents

Abstract

PURPOSE: To simplify detection of the rotation position of an upper rotating body based on a lower traveling body, in a construction machine provided with the upper rotating body. CONSTITUTION: In a construction machine having an upper rotating body 6 mounted on a lower traveling body 4 through a rotary joint, a hollow cylindrical cam 1 with which a rotary joint rotor 2 is surrounded is fixed to the lower traveling body 4 and the upper end face of the hollow cylindrical cam 1 is formed in a four-stage uneven surface state which is partitioned into every four regions of a region facing front, a region facing left, a region facing right, and a region facing rear. A driven cam 8 is suspended from the upper rotating body 6 and biased downward to bring into contact with the upper end surface of the hollow cylindrical cam 1, and rotated along the upper end surface. Further, the terminals of two limit switches 13 and 14 are engaged with the driven cam 8 and four kinds of switching states are formed according to displacement of upper and lower four-stage of the driven cam 8, and the rotation position of the upper rotating body 6 is detected.

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 structure and a lower traveling structure. is there.

[0002]

2. Description of the Related Art Conventionally, in this type of construction machine, an upper revolving structure is formed so as to be rotatable with respect to a lower traveling structure. Therefore, when the operator sits in the cockpit of the upper swing structure and is working while swinging the upper swing structure, the relative position of the upper swing structure with respect to the lower traveling structure may be lost, and There is a risk of accidental misjudgment of direction.

Therefore, in order to prevent such an erroneous operation of traveling, a potentiometer is incorporated in the rotary joint, and the position of the traveling motor is displayed in the cockpit by detecting the rotation angle of the upper revolving body, so that the operator can perform the upper revolving movement. Means for recognizing the relative position of the body with respect to the lower traveling body are known.

[0004]

Since the conventional turning position detecting device incorporates the potentiometer in the rotary joint as described above, not only the cost is greatly increased but also the assembling work is not easy. There is also a problem with the durability of the device.

Therefore, there is a technical problem to be solved in order to reduce the cost by making the turning position detecting device simpler and to improve the durability of the device. The purpose is to solve.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above object, and in a construction machine in which an upper swing body is mounted on a lower traveling body via a rotary joint, the upper swing body is rotated. A hollow cylindrical cam that surrounds the rotary joint rotor is fixed to the lower traveling body along the outer periphery of the rotary joint rotor that is fixed to the body and rotates, and the upper end surface of the hollow cylindrical cam is , A four-step concavo-convex shape divided into four regions, a frontward region, a leftward region, a rightward region, and a rearward region, and a driven cam vertically hung near the rotary joint rotor. Then, the lower end of the driven cam is brought into contact with the upper end surface of the hollow cylindrical cam, and the terminals of the two limit switches are engaged with the driven cam to displace the driven cam in four stages of up and down. In response A turning position detecting device for a construction machine for determining the turning position of an upper revolving structure by forming a combination of four kinds of switching states by turning ON and 0FF of the two limit switches to each other. It is a thing.

[0007]

When the upper revolving structure is rotated, the driven cam horizontally rotates along the upper end surface of the hollow cylindrical cam, and the four regions of the frontward region, the leftward region, the rightward region and the rearward region are provided. Displace the vertical position. Then, the two limit switches are switched to four kinds of switching states of 0FF and 0FF, ON and 0FF, 0FF and ON, and ON and ON in accordance with the displacement of the driven cam in four stages of up and down.

Thus, it is possible to determine whether the upper swing body is located in the frontward area, the leftward area, the rightward area or the rearward area based on the switching state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below 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 the rotary joint rotor 2. Then, as shown in FIG. 3, the upper end surface of the hollow cylindrical cam 1 is formed in a four-step concavo-convex shape in which the front area A, the left area B, the right area C, and the rear area D become higher in this order. ing. Further, the rotary joint rotor 2 is fixed to the upper revolving structure 6 via the detent 5 and rotates.

A driven cam 8 is vertically provided in the vicinity of the rotary joint rotor 2 by a bracket 7 fixed to the upper swing body 6 and is urged downward by a spring 9. Thus, the roller 10 provided at the lower end of the driven cam 8 contacts the upper end surface of the hollow cylindrical cam 1 and rotates along the upper end surface.

Further, a stay 11 is vertically provided on the bracket 7 in the vicinity of the driven cam 8, and a driven cam guide 12 is fixedly provided at a lower end portion of the stay 11 so that the driven cam 8 is fixed.
Is guided so as not to swing. Further, the stay 1
1, limit switches 13 and 14 are fixedly installed, and respective terminals of the limit switches 13 and 14 engage with the driven cam 8 and are mutually displaced with respect to the vertical displacement position of the driven cam 8 as described later. It is formed so that it turns ON and 0FF.

Thus, as shown in FIGS. 4 (a) and 4 (e), when the turning position of the upper swing body 6 with respect to the lower traveling body 4 is in the forward region a, the driven cam 8 is a hollow cylindrical cam. It is located on the upper end surface of the frontward area B of 1, and is in the lowermost displacement position by being biased by the spring 9, and both limit switches 13 and 14 are both in the 0FF state.

When the upper revolving structure 6 rotates counterclockwise with respect to the lower traveling structure 4 and comes to be positioned in the leftward region (b) as shown in FIG. 4 (f), the driven cam 8 springs. The hollow cylindrical cam 1 rides on the upper end surface of the leftward region B against the downward force of 9. Thus, as shown in FIG. 4B, the limit switch 13 is in the ON state and the limit switch 14 is in the switching state of 0FF.

Further, when the upper swing body 6 rotates counterclockwise and comes to be positioned in the rearward area D as shown in FIG. 4 (g), the driven cam 8 is moved to the rear of the hollow cylindrical cam 1. The uppermost displacement state is achieved by riding on the upper end surface of the facing area d. At this time, both limit switches 13 and 14 are turned on as shown in FIG. 4 (c).

Further, when the upper swing body 6 rotates counterclockwise and comes to be positioned in the rightward area C as shown in FIG. 4 (h), the driven cam 8 is urged downward by the spring 9. As a result, the hollow cylindrical cam 1 descends onto the upper end surface of the rightward area C. Then, as shown in FIG.
Limit switch 13 is 0FF, limit switch 14 is
An ON switching state is formed.

Thus, the limit switches 13 and 1
It is possible to determine whether the upper swing body 6 is located in the front area A, the left area B, the right area C, or the rear area D based on the mutual switching states of 4. 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 one.

[0017]

As described in detail in the above one 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, the driven cam and the two limit switches. There is. Therefore, as compared with the conventional means for incorporating a potentiometer, not only a great cost reduction can be realized, but also the assembling work becomes extremely easy.

Further, since the invention uses the mechanical cam mechanism, it is excellent in durability and can be easily maintained and repaired.

[Brief description of drawings]

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

FIG. 2 is a plan view of FIG.

FIG. 3 is a perspective view of a hollow cylindrical cam.

FIG. 4A is a partially cutaway front view showing an engaged state of a driven cam and two limit switches when in a frontward region. (B) A partially cutaway front view showing the engaged state of the driven cam and the two limit switches when in the leftward region. (C) A partially cutaway front view showing the engaged state of the driven cam and the two limit switches when in the rearward region. (D) A partially cutaway front view showing the engaged state of the driven cam and the two limit switches when in the rightward region. (E) thru | or (h) The top view which shows the attitude | position of the upper revolving superstructure with respect to a lower traveling body.

[Explanation of symbols]

 1 Hollow Cylindrical Cam 2 Rotary Joint Rotor 4 Lower Traveling Body 6 Upper Revolving Body 8 Driven Cam 13, 14 Limit Switch

Claims (1)

[Claims] 1. In a construction machine in which an upper revolving structure is mounted on a lower traveling structure via a rotary joint, the rotary joint rotor is fixed along the outer periphery of the rotary joint rotor fixedly mounted on the upper revolving structure. An enclosing hollow cylindrical cam is fixed to the lower traveling body, and an upper end surface of the hollow cylindrical cam is divided into four regions of a front region, a left region, a right region and a rear region. In addition to being formed in a four-step concavo-convex shape, a follower cam of an upper revolving body near the rotary joint rotor is vertically provided, and the lower end of the follower cam is brought into contact with the upper end surface of the hollow cylindrical cam, , By engaging the terminals of the two limit switches with the driven cam and turning the two limit switches ON and 0FF mutually in accordance with the displacement of the driven cam in four steps, the four types of switches. A turning position detecting device for a construction machine, wherein the turning position of an upper-part turning body is determined so as to form a combination of the turning states.