JP2000234351A - Construction machine with hydraulic travel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the temperature rise of hydraulic oil at the time of descent on a slope. SOLUTION: The flow of the pressure oil from a hydraulic pump is controlled by the travel spool 54T and boom spool 54B of a control valve 54 to control the drive of other hydraulic actuators such as a travel hydraulic motor 61 and the hydraulic cylinder of a boom 31A. The control valve 54 is arranged in an apparatus chamber 33 covered with a cover 33K, and the cover 33K is provided with an opening 33a guiding travel wind to the control valve 54. The control valve 54 is arranged so that the travel spool 54T is located at a nearest position to the opening 33a in the front of a vehicle. Travel wind is guided into the apparatus chamber 33 from the opening 33a to cool the travel valve element 54T during a travel. Even when the hydraulic oil in a travel circuit does not flow in an oil cooler during a descent on a slope by an engine brake, the travel circuit side of the control valve 54 is cooled, and the temperature rise of the hydraulic oil in the travel circuit can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a construction machine having a hydraulic traveling device.

[0002]

2. Description of the Related Art In a working vehicle such as a wheel shovel that moves on wheels with tires, a traveling hydraulic motor is driven by controlling the flow of hydraulic oil from a hydraulic pump by a control valve. The wheel type hydraulic excavator has a boom cylinder, an arm cylinder, or a turning hydraulic motor, and these are also driven by pressure oil controlled by the above-described control valve. In recent years, the traveling speed of construction machines traveling on general roads such as wheel-type hydraulic excavators has been increasing, and the engine horsepower allocated for traveling has increased, and the amount of heat generated during traveling has increased. When the vehicle travels with the engine brake, such as when going downhill, the control valve is switched to the neutral position, and the hydraulic circuit between the control valve and the traveling hydraulic motor becomes a closed circuit. Therefore, the hydraulic oil generated by the traveling hydraulic motor circulates through this closed circuit, and no pressure oil flows to the oil cooler provided between the control valve and the oil tank, and the hydraulic oil in this circuit becomes hot. There is a risk.

[0003]

SUMMARY OF THE INVENTION Therefore, Japanese Patent Application Laid-Open No. Hei 8-1
As in the hydraulic working machine disclosed in Japanese Patent No. 99624, it is conceivable to arrange a control valve in an air blowing area of an engine fan to cool hydraulic oil. However, the wind discharged from the engine fan is a relatively high-temperature wind after cooling the engine cooling water and the working oil.
It is difficult to suppress an increase in the temperature of the hydraulic oil when the traveling hydraulic device having a horsepower of about PS descends on a slope.

[0004] It is an object of the present invention to provide a construction machine having a hydraulic traveling device that suppresses a rise in the temperature of hydraulic oil during a descent.

[0005]

FIG. 3 shows an embodiment of the present invention.
This will be described with reference to FIGS. (1) The invention of claim 1 is applied to a construction machine that controls a flow of hydraulic oil from a hydraulic pump 52 by a control valve 54 to drive a traveling hydraulic motor 61 and another hydraulic actuator, respectively. The traveling hydraulic motor 61 is connected to the control valve 54.
And a second valve body 54B for controlling the flow of pressure oil to other actuators, and the first valve body 54B is provided in comparison with the second valve body 54B.
The above-mentioned object is achieved by arranging the control valve 54 so that the wind at the time of traveling is guided more to T. (2) According to a second aspect of the present invention, in the construction machine according to the first aspect, the control valve 54 is disposed in the equipment room 33 covered with the cover 33K. An opening 33a for guiding the traveling wind is provided. (3) The invention of claim 3 is applied to a construction machine that controls the flow of pressure oil from the hydraulic pump 52 by the control valve 54 to drive the traveling hydraulic motor 61 and other hydraulic actuators. The control valve 54 has a first valve body 54T for controlling the flow of pressure oil to the traveling hydraulic motor and a second valve body 54 for controlling the flow of pressure oil to other actuators.
B is provided, and the wind at the time of traveling is guided to the first valve body 54T more than the second valve body 54B, thereby achieving the above-described object. (4) According to a fourth aspect of the present invention, in the construction machine of the third aspect, the control valve is disposed in the equipment room 33 covered with the cover 33K, and the cover 33K is provided with an opening 33a.
a, at least a duct 40 for guiding the traveling wind from the first valve body 54T to the first valve body 54T is provided.

[0006] In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a wheel shovel to which the present invention is applied, FIG. 2 is a front view, and FIG. 3 is a top view. As shown in the figure, the wheel shovel includes a lower traveling body 10 and a lower traveling body 10 via a turning device 20.
And an upper revolving body 30 rotatably connected to the upper part of the upper part. The upper swing body 30 has a swing body frame 38 including a main frame 38a, a right frame 38b, and a left frame 38c. The revolving frame 38 has a boom 31
A, a working front attachment 31 comprising an arm 31B, a bucket 31C, and a cab 32 provided with a traveling operation member, a front attachment operation member, and the like.
And an equipment room 33 covered with a cover 33K.

[0008] As shown in FIG. 3, the equipment room 33 includes an engine 51 and a hydraulic pump 52 driven by the engine 51.
A radiator 53a for cooling engine cooling water, an oil cooler 53b for cooling hydraulic oil, and a hydraulic pump 5
A control valve 54 and the like for controlling the flow of the pressure oil from the fuel cell 2 are provided. As shown in FIG. 1, the lower traveling body 10 includes a traveling hydraulic motor 61 driven by pressure oil controlled by a control valve 54, a transmission 62 for shifting the driving force of the hydraulic motor 61, and a transmission 62. Propeller shaft 63 and axle 6 driven to rotate by the output of
4 (FIG. 2) to rotate the wheel-type hydraulic shovel.

As shown in FIG. 3, the control valve 54 includes a traveling spool (valve element) 54T and a boom spool (valve element).
54B and a turning spool 54S. Control valve 5
4 is a bracket 5 attached to the revolving frame 38 so that the traveling spool 54T is located at the forefront in the vehicle traveling direction among the plurality of spools as shown in FIG.
5 is provided on the upper surface. Then, each spool of the control valve 54 is operated according to the operation of the operation member in the driver's seat, and the corresponding actuator is driven. Equipment room cover 33
An opening 33a for guiding the traveling wind TW for cooling the traveling spool 54T is provided in the front surface of the vehicle traveling in K. Further, an under cover 39 is provided on the bottom of the revolving frame 38.
However, the under cover 39 where the control valve 54 is located is provided with an opening 39 a for discharging the traveling wind TW taken into the equipment room 33 to the outside of the equipment room 33.

[0010] In the wheel type hydraulic excavator thus configured, as shown in FIG.
a, the traveling wind TW is introduced into the equipment room 33, and the control valve 5
4 is cooled and discharged out of the equipment room 33 from the opening 39a. Since the traveling spool 54T of the control valve 54 is disposed forward in the vehicle traveling direction, it is effectively cooled by the traveling wind TW. Therefore, the hydraulic circuit between the traveling motor 61 and the control valve 54 becomes a closed circuit as in the case where the vehicle descends on the slope for a long time with the engine brake, and even if the hydraulic oil in this circuit is not cooled by the oil cooler 53B, the control valve 54
Is cooled by the traveling wind TW, so that the temperature rise of the hydraulic oil can be suppressed. As a result, the heat balance of the hydraulic oil is improved, the capacity of the oil cooler can be reduced, and the cost and size can be reduced. Further, the heat-resistant condition of the seal of the hydraulic device can be relaxed, thereby making it possible to reduce the cost of the hydraulic device.

In the above embodiment, the traveling spool 5
The control valve 54 is set so that 4T is positioned at the forefront of the vehicle traveling direction.
Is disposed in the equipment room 33, but if the traveling valve element 54T can be sufficiently cooled by traveling wind, the traveling valve element 5T is not necessarily required.
It is not necessary to arrange 4T ahead of the vehicle traveling direction. For example, as shown in FIG. 5, the control valve 54 is disposed in a lower place slightly behind the case of FIG. You may make it lead to the valve body 54T.

[0012]

As described above in detail, according to the present invention, the traveling valve element in the control valve is cooled by traveling wind during traveling, so that the valve element is neutralized as in a downhill. Thus, even when the operating oil in the traveling circuit does not flow to the oil cooler, the temperature of the operating oil in the traveling circuit can be suppressed. as a result,
Since the heat balance of the hydraulic oil is improved, the capacity of the oil cooler can be reduced, which contributes to cost reduction and miniaturization. In addition, the heat-resistant condition of the seal of the hydraulic device can be reduced, thereby reducing the cost.

[Brief description of the drawings]

FIG. 1 is a side view of a wheel type hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is an enlarged view showing the vicinity of the control valve of FIG. 1;

FIG. 5 is an enlarged view similar to FIG. 4, showing a modification;

[Explanation of symbols]

 30: Upper swing body 33: Equipment room 33K: Equipment room cover 33a: Opening 39a: Opening 40: Duct 54: Control valve 54T: Traveling valve body 54B: Boom valve body

Claims (4)

[Claims] 1. A construction machine for controlling a flow of hydraulic oil from a hydraulic pump by a control valve to drive a traveling hydraulic motor and another hydraulic actuator, respectively, wherein the control valve is configured to control a flow of the hydraulic oil to the traveling hydraulic motor. And a second valve body that controls the flow of pressure oil to the other actuator, and the wind during traveling on the first valve body is more than that of the second valve body. A construction machine having a hydraulic traveling device, wherein the control valve is arranged so as to be guided more. 2. The construction machine according to claim 1, wherein the control valve is disposed in an equipment room covered with a cover, and the cover is provided with an opening for guiding traveling wind to at least the first valve body. A construction machine having a hydraulic traveling device. 3. A construction machine in which a flow of hydraulic oil from a hydraulic pump is controlled by a control valve to drive a traveling hydraulic motor and another hydraulic actuator, respectively, wherein the control valve is configured to control a flow of hydraulic oil to the traveling hydraulic motor. And a second valve body that controls the flow of pressure oil to the other actuator, and the wind during traveling on the first valve body is more than that of the second valve body. A construction machine having a hydraulic traveling device, which is guided to a large extent. 4. The construction machine according to claim 3, wherein the control valve is disposed in an equipment room covered with a cover, the cover is provided with an opening, and traveling air flows from the opening to the first valve body. A construction machine having a hydraulic traveling device, wherein a guiding duct is provided.