JPH0392486A - Running direction control device of construction machine - Google Patents

Abstract

PURPOSE:To control the running direction by making the operation direction of an operation device and the running direction of a lower running body respond each other, and to improve the operating efficiency of the operation device, by providing a direction shift reversing device to reverse the shift direction of a change-over valve for running by an operation device. CONSTITUTION:Depending on the posture whether an upper rotary body 2 is at the position facing forward or facing backward, the shift direction of a change-over valve 25 for running is reversed, and when it is at the position facing sideway, a change-over valve 27 as a shift direction reversing device is held at the neutral position, for example. Then, even the upper rotary body 2 is at the position facing sideway, the pilot pressure from a pilot valve (operation device) 8 is fed to each hydraulic pilot valve of the direction change-over valve 25.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is provided in a construction machine such as a hydraulic excavator, and even when the upper revolving body is turned to a backward position with respect to the lower traveling body, the traveling The present invention relates to a traveling direction control device for a construction machine, in which a lower traveling body is caused to travel in accordance with the operating direction of an operating means.

[Prior Art] FIGS. 3 to 5 show a running direction control device for a hydraulic excavator as an example of a running direction control device for a construction machine according to the prior art.

In the figure, 1 is an undercarriage body, 2 is an upper revolving body rotatably mounted on the undercarriage body l, and the upper revolving body 2 includes a revolving frame 3 forming a skeleton structure, It is generally composed of a driver's cab 4, a machine room 5, and a counterweight 6 provided above, and a driver's seat 7 is provided in the driver's cab 4 on a floor plate 4A as shown in FIG. An operating lever 8A of a pressure reducing valve type pilot valve 8 constituting operating means for driving is provided on the front side of the driver's seat 7, and the operating lever 8A is moved from a neutral position N to a forward position F.
When the lower traveling body 1 is tilted in the direction of the arrow A, the lower traveling body 1 travels (forward) in the direction of the arrow A, and when it is tilted toward the reverse position R, the lower traveling body 1 travels in the direction of the arrow B (reverse).

Here, the lower traveling body 1 is provided with a hydraulic motor (not shown) for traveling, and a hydraulic motor (not shown) for traveling is provided in the machine room 5, which is driven by a prime mover such as an engine and supplies and discharges pressure oil to the hydraulic motor for traveling. A hydraulic bomb (not shown) is provided as a source. A travel switching valve (not shown) for switching the rotational direction of the hydraulic motor is provided between the hydraulic bomb and the hydraulic motor, and the travel switching valve is connected to the pilot valve 8.
By switching the hydraulic motor using the pilot pressure from the The rotation is reversed, and the lower traveling body 1 begins to travel in the directions of arrows A and B.

9 indicates a working device provided at the front part of the revolving upper structure 2;
The working device 9 is composed of a boom 10, an arm 11, a packet 12, etc., and by rotating the packet 12 while raising and lowering the boom 10 and arm 11,
Excavation work such as earth and sand is now being carried out.

Reference numeral 13 indicates a turning angle detector located on the turning center O of the upper rotating structure 2 and provided between the upper rotating structure 2 and the lower traveling structure 1. -48044
As described in the above publication, it is constituted by, for example, a potentiometer, and is adapted to detect the turning angle of the upper rotating body 2 with respect to the lower traveling body 1. That is, the detector 13 detects that the rotation angle of the upper rotating body 2 is O°~90', 270''~36
00 is detected as the forward position, and when the turning angle is in the range of 90" to 270@, it is detected as the backward position. When the upper rotating body 2 is in the backward position, a polarity inversion circuit (not shown) is detected. ) etc., the traveling direction of the lower traveling body 1 is reversed from the forward position.

In the hydraulic excavator configured in this way, the pilot valve 8 is controlled by whether the operator in the operator's cab 4 tilts the operating lever 8A from the neutral position N to the forward position F or to the reverse position R. The direction of the pilot pressure supplied to the travel switching valve is reversed, which reverses the switching direction of the travel switching valve, which changes the direction of the pressure oil supplied and discharged from the hydraulic bomb to the travel hydraulic motor. In other words, the lower traveling body 1 is driven in the direction of arrow A or the direction of arrow B by this hydraulic motor. Further, the upper rotating body 2 is rotated on the lower traveling body 1 by a rotating motor (not shown) or the like around the rotation center O, for example, from the forward facing position shown in FIG. 5(A) to the position shown in FIG. 5(B). It is designed to rotate appropriately to the rearward facing position shown.

By the way, in a normal hydraulic excavator, etc., the
When the upper rotating body 2 is placed in the forward position with respect to the lower traveling body 1 as shown in FIG.
The lower traveling body 1 can be moved forward (forward) in the direction of arrow A in accordance with the direction of operation of , and by tilting backward to the reverse position R, the lower traveling body 1 can be moved forward in the direction of arrow B. It is possible to run backwards (reverse) in the same direction. However, when the upper rotating body 2 is turned to a position facing backward with respect to the lower traveling body 1 as shown in FIG. Therefore, when the operating lever 8A is tilted forward by the driver to the forward position F, the lower traveling body 1 begins to travel in the direction of the arrow A in the opposite direction to the direction of the forward position F. , reverse position R
If the vehicle is tilted in the direction of arrow B, it will run in the opposite direction. For this reason, for example, in FIG. 5(B), when the lower traveling body 1 is run in the direction of arrow B, the operating lever 8A is tilted to the reverse position R, and when it is run in the direction of arrow A, it is tilted to the forward position F. Therefore, manual operation of the operating lever 8A becomes difficult, increasing driver fatigue and reducing safety.

Therefore, in the above-mentioned conventional technology, a turning angle detector 13 etc. is provided,
When the upper rotating body 2 is in the backward position as illustrated in FIG. If the operating lever 8A is tilted backward to the reverse position R, the undercarriage body 1 can be moved in the direction of arrow A. This allows the tilting operation direction of the operating lever 8A to correspond to the traveling direction of the lower traveling body 1.

[Problem to be Solved by the Invention] However, in the above-mentioned conventional technology, the turning angle of the upper rotating body 2 is determined by the turning angle detector l3 from 0° to 90 @ 270'.
360 @ is detected as the forward position,
When the turning angle is in the range of 90° to 270°, it is detected as a backward position, and the traveling direction of the lower traveling body 1 is reversed depending on when the upper rotating body 2 turns to the forward position and when it turns to the backward position. Therefore, when the upper rotating body 2 is turned to a sideways position near a turning angle of 90' or 270°, the running direction of the lower rotating body 1 may be suddenly reversed. Operation lever 8
The drawback is that the tilting operation of A is very difficult and safety cannot be improved.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and the present invention allows the traveling direction of the lower traveling body to correspond to the operating direction of the operating means even when the upper rotating body is turned from the forward facing position to the rearward facing position. This is a running direction control device for construction machinery that can prevent the running direction of the undercarriage from changing suddenly when it is turned to a sideways position, improving the operability and safety of the operating means. It provides:

[Means for Solving the Problems] The feature of the configuration adopted by the present invention in order to solve the above-mentioned problems is that the upper rotating body turns to a forward position with a predetermined turning range with respect to the lower traveling body. , a turning direction detecting means for detecting whether the upper rotating body has turned to a backward position with a predetermined turning range, and determining that when the upper rotating body turns to a sideways position, it is outside the detection range; and a turning direction detecting means based on a signal from the turning direction detecting means. ,
The rotating upper structure includes switching direction reversing means for reversing the switching direction of the traveling switching valve by the operating means when the upper revolving body swings to the forward position and when the upper revolving body swings to the rearward position.

Furthermore, a release means may be provided for canceling the reversing operation by the switching direction reversing means.

Further, the operating means is constituted by a pressure reducing valve type pilot valve, the traveling switching valve is constituted by a hydraulic pilot type directional switching valve which is switched by pilot pressure from the pilot valve, and the switching direction reversing means is It is provided in the middle of a pair of pilot pipes connecting each hydraulic pilot part of the directional control valve and the pilot valve, and the direction of the pilot pressure supplied from the pilot valve to each hydraulic pilot part of the directional control valve is swiveled. Preferably, the switching valve is configured by a switching valve that switches based on a signal from the direction detection means.

A release means is provided in the middle of each of the pilot pipes, and the release means bypasses the pilot pressure from the pilot valve before and after the switching valve, and applies the pilot pressure from the pilot valve to each hydraulic pilot section of the directional switching valve. It is preferable to set it as the structure which supplies.

[Effect]

With the above structure, the switching direction of the traveling switching valve can be reversed depending on whether the upper rotating body is in the forward position or the rearward position, and when it is in the sideways position, the switching direction of the switching valve as switching direction reversing means can be changed, for example. Can be held in a neutral position. Also, even when the upper rotating body is in the horizontal position,
The release means allows pilot pressure from the pilot valve to be supplied to each hydraulic pilot section of the directional control valve.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. In addition, in the embodiment, the above-mentioned figures 3 to 5 are used.
Components that are the same as those of the prior art shown in the figures are given the same reference numerals, and their explanations will be omitted.

In the figure, 21 is a hydraulic motor for traveling provided in the lower traveling body 1, 22 is a hydraulic bomb that supplies and discharges pressure oil to the hydraulic motor 21, and the hydraulic bomb 22 constitutes a hydraulic source together with a tank 23, Inside the machine room 5, it is driven together with a pilot pump 28, which will be described later, by a prime mover such as an engine.

24A and 24B are a pair of main pipes connecting the hydraulic bomb 22, tank 23, and hydraulic motor 21; 25 is the main pipe 2;
4A and 24B are shown as directional switching valves as traveling switching valves, and the directional switching valves 25 are composed of hydraulic pilot type directional switching valves with 4 boats and 3 positions.
By supplying pilot pressure to the right hydraulic pilot parts 25A and 25B, it is possible to shift from the neutral position (a) to the left and right switching positions (b). (c), and the hydraulic motor 21 is rotated forward and reverse in the directions of arrows A and B.

26A and 26B are hydraulic pilot parts 2 of the directional switching valve 25
A pair of pilot pipes connecting 5A, 25B and the output side of the pilot valve 8, 27 is the pilot pipe 26A,
26B is shown, and the switching valve 27 is constituted by an electromagnetic directional switching valve with 4 boats and 3 positions. Solenoids 27A and 27B are provided on both right sides. The solenoids 27A and 27B are connected to position sensors 32A and 32, which will be described later.
By being connected to B and being excited by signals from these position sensors 32A and 32B, the switching valve 27 is switched from the neutral position (A) to the left and right switching positions (Open) and (C). There is. Here, the switching valve 27 is in the switching position (B).
and the switching position (c), the direction of the pilot pressure supplied from the pilot valve 8 to the hydraulic pilot parts 25A, 25B of the directional switching valve 25 is reversed.

That is, the high pressure side of the pilot valve 8 is connected to the pilot bomb 28.
The low pressure side is connected to the tank 23. Then, with the switching valve 27 switched to the switching position (b),
When the operating lever 8A is tilted from the neutral position N to the forward position F, the pilot pressure from the pilot valve 8 is supplied to the hydraulic pilot portion 25A of the directional switching valve 25, and the directional switching valve 25 is in the switching position (B). When the switch is switched and the operating lever 8A is tilted to the reverse position R, pilot pressure from the pilot valve 8 is supplied to the hydraulic pilot portion 25B of the directional switching valve 25, and the directional switching valve 25 is moved to the switching position (
c).

When the switching valve 27 is switched to the switching position (c), the directional switching valve 25 is moved from the neutral position (a) to the switching position by tilting the operating lever 8A from the neutral position N to the forward and reverse positions F and H. It can be switched to (c) and (b) by reversing it.

29A and 29B are solenoid valves located between the switching valve 27 and the pilot valve 8 and provided in the middle of the pilot pipes 26A and 26B as other switching valves; 30 is the solenoid valve 29;
The solenoid valves 29A and 29B constitute a release means together with the solenoid valves 29A and 29B.
29B shows a release switch that outputs a switching signal. The release switch 30 is provided in the driver's cab 4, and when pressed by the driver, changes the solenoid valves 29A and 29B from the illustrated control position (A) to the release position ( (b). And, the solenoid valves 29A and 29B are pilot valves in the release position (b). The pilot pressure from the pilot pipes 26A and 26B is transferred to the branch pipe 31A. The hydraulic pressure is supplied to the hydraulic pilot portions 25A and 25B of the directional switching valve 25 while being bypassed before and after the switching valve 27 via 31B.

Furthermore, 32A・■. Reference numeral 32B indicates a position sensor as a turning direction detection means for detecting whether the upper rotating body 2 is in a forward position or a backward position with respect to the lower traveling body 1, and the position sensors 32A and 32B are shown in FIG. As shown in
Conductive plates 34A, 34B are arranged in an arc shape over a predetermined angle θ (for example, θ=160') with dead zones 33A, 33B sandwiched between them on an insulating substrate 33, and It is roughly composed of a brush 36 that supplies voltage from the battery 35 as a DC power source to the solenoids 27A and 27B of the switching valve 27 by sliding contact, and while the brush 36 is in sliding contact with the conductive plate 34A, the upper revolving body 2 is detected as being in the forward position, and the conductive plate 34B
The upper revolving body 2 is detected as being in a backward position while it is in sliding contact with the upper rotating body 2, and the positions of the dead zones 33A and 33B are outside the detection range.

Here, a support shaft 37 is fixed to the center part of the base plate 33, and the support shaft 37 is fixed to, for example, the rotation center O (the fifth
(see figure) and is positioned on the upper revolving body 2 side together with the base plate 33. Further, a ring 38 forming a part of the brush 36 is rotatably fitted on the outer periphery of the support shaft 37, and the ring 38 is attached to the lower traveling body 1 side together with the brush 36, and the battery is It is connected to 35. When the upper revolving body 2 is in the forward position as illustrated in FIG.
When the upper rotating body 2 turns to the backward position with respect to the lower traveling body 1 as illustrated in FIG. 5(b), the brush 36 The position sensor 32B contacts the conductive plate 34B and outputs a signal that excites the solenoid 27B.

The running direction control device for a hydraulic excavator according to this embodiment has the above-described configuration, and the running direction control operation thereof will be explained next.

First, when the upper rotating body 2 is in the forward position with respect to the lower traveling body 1 as illustrated in FIG. It is in a state where it has been switched from the switching position (a) to the switching position (b).

When the operating lever 8A is tilted from the neutral position N to the forward position F in this state, the pilot pipe 26 is connected from the pilot valve 8 to the hydraulic pilot portion 25A of the directional control valve 25.
Pilot pressure is supplied via A, and the directional control valve 25
is switched from the neutral position (a) to the switching position (b).

As a result, the pressure oil from the hydraulic bomb 22 is supplied to the hydraulic motor 21 through the main pipe 24A, and the oil pressure cylinder 2l rotates in the direction of arrow A to move the lower traveling body l as shown in FIG. 5(A). Make it run (forward) in the direction of arrow A.

Further, when the operating lever 8A is tilted from the neutral position N to the reverse position R side, the pilot pressure from the pilot valve 8 is supplied to the hydraulic pilot part 25B of the directional switching valve 25 via the pilot pipe 26B, The switching valve 25 is switched to the switching position (c), the rotational direction of the hydraulic motor 2l is reversed in the direction of arrow B, and the lower traveling body 1 runs (reverse) in the direction of arrow B in FIG. 5(a). .

On the other hand, when the upper revolving body 2 is turned to the backward position as illustrated in FIG. From this point on, the direction of pilot pressure supply is reversed from when it is in the switching position (B). That is, when the operating lever 8A is tilted toward the forward position F in this state, the pilot pressure from the pilot valve 8 is supplied to the hydraulic pilot portion 25B of the directional switching valve 25.
is switched to the switching position R (c), the hydraulic motor 2l is rotated in the direction of arrow B, the lower traveling body l is moved in the direction of arrow B in FIG. 5(b), and the operating lever 8A is tilted ( forward position F)
It can be run in the direction corresponding to the operating lever 8.
When A is tilted to the reverse position R side, the directional control valve 2
5 is switched to the switching position (b), the hydraulic motor 21 is rotated in the direction of arrow A, and the lower traveling body 1 is moved in the direction of arrow A in FIG. Reverse position R
) can be made to run in the direction corresponding to the direction.

Therefore, the position sensors 32A and 32B detect whether the upper rotating body is in the forward position or the backward position, and the switching valve 27 is switched to the switching position (B) or (C) based on the signals from the position sensors 32A, 32B. By switching from the pilot valve 8 to each hydraulic pilot section 25A, 2 of the directional control valve 25
The direction of the pilot pressure supplied to the control lever 8B can be reversed, and even when the upper revolving body 2 is turned to the backward position as illustrated in FIG. The lower traveling body 1 can be made to travel in the directions of arrows B and A in the direction corresponding to the backward traveling position R), and the operability of the operating lever 8A can be improved.
It is possible to solve problems such as the vehicle running in the opposite direction to the operating direction of the operating lever 8A and causing a collision.

Further, a substrate 33 forming a part of the position sensors 32A, 32B
Above, as shown in FIG. 2, dead zones 33A and 33B are formed between the conductive plates 34A and 34B on both the left and right sides of the substrate 33, for example, over an angular range (180° θ), respectively. When the brush 36 rotates to the position of the dead zone 33A, 33B, it is out of the detection range of the position sensors 32A, 32B, the solenoids 27A, 27B are both demagnetized, and the switching valve 27 returns to the neutral position (A). Therefore, while rotating the upper rotating body 2 from the forward position (the position of the conductive plate 34A) to the backward position (the position of the conductive plate 34B), the switching valve 27 changes from the switching position (B) to the switching position (
It is possible to prevent the upper rotating body 2 from suddenly switching to (c), and the upper rotating body 2 can be placed in a horizontal position to the left or right with respect to the lower traveling body 1, for example, in the 5th position.
When turning to a position near the turning angle of 90" or 270° as shown in FIGS. can improve sex.

Furthermore, in this embodiment, solenoid valves 29A, 29B are provided in the middle of the pilot pipes 26A, 26B, and the solenoid valves 29A, 29B are provided in the middle of the pilot pipes 26A, 26B.
29B to the control position by manual operation of the release switch 3o.
Since it is configured to switch from (a) to the release position (b),
For example, if you want to run the lower traveling body 1 while the upper rotating body 2 is turned to the left or right sideways position, the solenoid valves 29A and 29B are switched to the release position (B) using the release switch 30. For example, the pilot pressure from the pilot valve 8 is transferred to the directional control valve 25 via the branch pipes 31A, 31B, etc.
The hydraulic pressure can be supplied to the hydraulic pilot parts 25A and 25B, and the lower traveling body 1 can be made to travel in the same way as a normal hydraulic excavator by operating the operating lever 8A. In addition, even for drivers who are accustomed to operating a normal hydraulic excavator (the current one), it is recommended to switch the release switch 3o before operating the hydraulic excavator.
By manually operating the underbody 1, various effects can be achieved, such as being able to run the undercarriage 1 with the same operation as the current one.

In the above embodiment, the hydraulic pilot type directional switching valve 25 is used as the travel switching valve, but
Alternatively, the directional control valve 25 may be configured by an electromagnetic directional control valve or the like that is substantially similar to the directional control valve 27. In this case, the switching direction reversing means, the release means, etc.
, position sensor 32A in place of the solenoid valves 29A, 29B, etc.
, 32B and a controller that switches and controls the directional switching valve 25 based on signals from operating means for traveling.

Further, in the above embodiments, a hydraulic excavator has been described as an example, but the present invention is not limited to this. It can also be applied to construction machinery such as.

[Effects of the Invention] As detailed above, according to the present invention, a turning direction detection means is provided which detects whether the upper rotating body is in a forward position or a rearward position and excludes the sideways position from the detection range, When the upper rotating body turns to the backward position, the switching direction of the traveling switching valve by the operating means is reversed, so for example, the operating direction of the operating means and the traveling direction of the lower traveling body are made to correspond to each other, so that the traveling direction is changed. In addition to improving the operability of the operating means, it is also possible to prevent the traveling direction from changing suddenly when the revolving upper structure turns to the sideways position, thereby improving safety. Further, when the upper revolving body turns to a sideways position, the lower traveling body can be caused to travel by the release means in the same way as current construction machinery, and various other effects are achieved.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a hydraulic circuit diagram for traveling, FIG. 2 is an explanatory diagram showing the configuration of a position sensor, and FIGS. 3 to 5 are conventional techniques. FIG. 3 is an overall perspective view of the hydraulic excavator, FIG. 4 is a cross-sectional explanatory view showing the driver's cab, and FIGS. FIG. 2 is a plan view of a hydraulic excavator. DESCRIPTION OF SYMBOLS 1... Lower traveling body, 2... Upper rotating body, 4... Driver's cab, 8... Pilot valve (operating means), 8A...
Operation lever 9... Working device, 2l... Hydraulic motor, 22... Hydraulic bomb, 25... Directional switching valve (traveling switching valve> 26A, 26B... Pilot pipe,
27...Switching valve (switching direction reversal means), 28...Pilot pump, 29A. 29B... Solenoid valve, 30.
...Release switch, 31A, 31B... Branch pipe, 3
2A. 32B...Position sensor (turning direction detection means).

Claims (4)

[Claims] (1) an undercarriage body, an upper revolving body which is rotatably mounted on the undercarriage body and is provided with at least a driver's cab;
In a construction machine comprising a traveling operation means for switching a traveling switching valve in order to move backward, the construction machine determines whether the upper rotating body has turned to a forward position with a predetermined turning range with respect to the lower traveling body or not. a turning direction detecting means for detecting whether the upper rotating body has turned to a backward position with a turning range of A construction machine comprising switching direction reversing means for reversing the switching direction of the traveling switching valve by the operating means when the upper revolving body swings to a forward position and when the upper rotating body swings to a backward position. Travel direction control device. (2) A running direction control device for a construction machine according to claim (1), further comprising a release means for releasing the reversing operation by the switching direction reversing means. (3) The operating means is constituted by a pressure reducing valve type pilot valve, the traveling switching valve is constituted by a hydraulic pilot type directional switching valve which is switched by pilot pressure from the pilot valve, and the switching direction reversing means is provided in the middle of a pair of pilot pipes connecting each hydraulic pilot section of the directional control valve and the pilot valve, and indicates the direction of pilot pressure supplied from the pilot valve to each hydraulic pilot section of the directional control valve. A traveling direction control device for a construction machine according to claim (1) or (2), which comprises a switching valve that switches based on a signal from a turning direction detection means. (4) A release means is provided in the middle of each of the pilot pipes, and the release means bypasses the pilot pressure from the pilot valve before and after the switching valve, and bypasses the pilot pressure from the pilot valve before and after the switching valve to each hydraulic pilot section of the directional switching valve. A running direction control device for a construction machine according to claim (3), which is configured to supply the following.