JP2017145848A - Work machine with work oil heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a hydraulic actuator to be always operated without any trouble by heating work oil for operating the hydraulic actuator [and/or work oil for operating a throttle valve for controlling the hydraulic actuator] even in the case that the work machine is stopped in its operation for long hours when the hydraulic driving type work machine is operated at a cold district.SOLUTION: A hydraulic driving type work machine driven by a hydraulic actuator 22 is enabled to heat work oil for a hydraulic actuator or its throttle valve for controlling operation at a cold district by installing a heating device H1 for heating work oil for operating the hydraulic actuator at the hydraulic actuator itself or at a position near the hydraulic actuator or by installing a heating device H2 for heating the work oil for operating the throttle valve at a throttle valve 23 itself for controlling the discharged work oil from the hydraulic actuator or a location near the throttle valve.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hydraulically-driven work machine equipped on a work vehicle such as a bridge inspection vehicle or an aerial work vehicle (in addition, a crane vehicle or a civil work vehicle can also be applied). With hydraulic oil heating device that prevents the hydraulic oil that operates the hydraulic actuator (or the throttle valve for hydraulic actuator control) in cold regions from becoming abnormally cold (or can be heated even if the hydraulic oil becomes abnormally cold) It relates to work equipment.

  If the hydraulically-driven work machine is stopped for a long time in a cold region, the hydraulic oil to the hydraulic actuator of the work machine does not circulate, so the hydraulic oil that operates the hydraulic actuator may become abnormally cold. When the hydraulic oil becomes an abnormally low temperature, the viscosity of the hydraulic oil becomes high and the fluidity is deteriorated. As a result, the response of the hydraulic actuator may be deteriorated or sometimes the hydraulic actuator cannot be operated. In addition to the fact that the fluidity of the hydraulic oil that operates the hydraulic actuator deteriorates due to the abnormally low temperature of the hydraulic oil, the hydraulic actuator cannot be operated. The fluidity of the hydraulic oil that operates the throttle valve (counter balance valve) may deteriorate.

  Then, for example, during the operation of a bridge inspection vehicle or an aerial work vehicle, the hydraulic oil that operates the hydraulic actuator as described above (or / and the hydraulic oil for operating the throttle valve) becomes abnormally low and the hydraulic actuator is If it becomes impossible to move, the worker who is on the workbench at the end of the boom cannot return to the ground (on the bridge) by the work machine's own power (requires rescue by another work vehicle) Can not be stored (work vehicle cannot be moved), so the road blockage state becomes long (traffic jam) occurs.

  By the way, among known documents, for example, as disclosed in Japanese Patent Application Laid-Open No. 8-284907 (Patent Document 1), a hydraulic oil tank and a hydraulic pump are used to improve engine startability of a hydraulically driven work machine. A pipe that connects (driven by an engine) is heated by a heater. In this known example technique, the hydraulic oil sucked into the hydraulic pump is heated by a heating heater (lowering the hydraulic oil viscosity), thereby reducing the driving force for the hydraulic pump, thereby starting the engine. It can be improved.

JP-A-8-284907

  However, in the device disclosed in Patent Document 1, the startability of the engine that drives the hydraulic pump can be improved by heating the hydraulic oil sucked into the hydraulic pump (lowering the hydraulic oil viscosity). However, if the operation is stopped for a long time in an extremely low temperature state in a cold region, even if the engine continues to operate (even if the hydraulic oil in the range from the hydraulic oil tank to the hydraulic pump is heated) The hydraulic oil in the vicinity of various hydraulic actuators on the tip side of the work machine often becomes abnormally low in temperature, and in this case, the work machine may not perform a desired operation. That is, when the hydraulic oil near the hydraulic actuator on the front end side of the work machine becomes abnormally low in temperature, the hydraulic oil viscosity becomes high and fluidity deteriorates. As a result, even if the hydraulic actuator is operated, it cannot be operated. Or, even if it can be operated, the problem that the operating speed is slowed down and the working efficiency is deteriorated cannot be improved.

  Therefore, the present invention provides a hydraulic oil for operating a hydraulic actuator (or / and a throttle valve for controlling a hydraulic actuator) even when the operation is stopped for a long time when a hydraulically driven working machine is used in a cold region. It is made for the purpose of providing the working machine with a hydraulic oil heating apparatus which can heat the hydraulic oil.

  The present invention has the following configuration as means for solving the above problems.

  The present invention is directed to a working machine driven by a hydraulic actuator, and more specifically, hydraulic oil (or / and a throttle valve for controlling the hydraulic actuator) for operating the hydraulic actuator even in use in a cold region. Is a working machine equipped with a hydraulic oil heating device that heats the hydraulic oil so that it does not become abnormally low, and has the following two inventions (Claim 1 and Claim 2).

  In addition, as a work vehicle equipped with a working machine that is the subject of the present application, a bridge inspection car or an aerial work vehicle that may be operated in a cold region with the hydraulic actuator for driving the work machine stopped for a long time. However, in these work vehicles (bridge inspection vehicles and aerial work vehicles), an operator gets on the work table provided at the tip of the boom to perform various operations. When the work on the work table is completed, the worker who has been on the work table needs to return to the ground by storing the work machine.

  The working machine with a hydraulic oil heating device according to the first aspect of the present invention is a working machine driven by a hydraulic actuator, wherein hydraulic oil for operating the hydraulic actuator is applied to the hydraulic actuator itself or a position near the hydraulic actuator. It is characterized by providing a heating device for heating.

  According to the first aspect of the present invention, when the hydraulic actuator for operating the hydraulic actuator is heated by the heating device, even when the hydraulic actuator is stopped for a long time in a cold region, the hydraulic actuator is restarted. Since the hydraulic actuator is operated with the hydraulic oil heated to a high temperature, the hydraulic actuator immediately operates without any trouble.

  According to a second aspect of the present invention, there is provided a working machine equipped with a hydraulic oil heating device, wherein the throttle is driven by a hydraulic actuator and includes a throttle valve that controls hydraulic oil discharged from the hydraulic actuator. A heating device for heating the hydraulic oil that operates the throttle valve is provided in the valve itself or in the vicinity of the throttle valve.

  The invention of claim 2 of the present application has the following background. That is, in this type of hydraulically driven work machine, in many cases, the hydraulic oil discharged from the hydraulic actuator for driving the work machine is controlled by a throttle valve (for example, a counter balance valve). The hydraulic oil supply passage to the oil passage and the throttle valve is narrow (or narrow), and if the hydraulic actuator has been stopped for a long time in a cold region, the hydraulic oil that operates the throttle valve is relatively short. It tends to become abnormally low. When the hydraulic fluid that operates the throttle valve becomes abnormally low in temperature, the viscosity of the hydraulic fluid increases (the fluidity deteriorates) and the throttle valve may not operate, but the throttle valve does not operate. And the hydraulic actuator cannot be operated, and the working machine cannot be moved.

  Therefore, in the working machine with the hydraulic oil heating device according to the second aspect of the present invention, the hydraulic oil that operates the throttle valve is heated by the heating device, so that the throttle valve is normally operated when the hydraulic actuator is operated. The hydraulic actuator can be operated without causing any trouble.

  In the invention of the present application, the configuration of claim 1 (heating the hydraulic oil that operates the hydraulic actuator) and the configuration of claim 2 (operation that operates the throttle valve for controlling the hydraulic fluid discharged from the hydraulic actuator). Can be used independently for a single work machine, while the configuration of claim 1 and the configuration of claim 2 can be used for a single work machine. It can also be shared.

  In the invention of claim 1 of the present application, since the hydraulic oil that operates the hydraulic actuator is heated by the heating device, the hydraulic actuator is operated even if the hydraulic actuator is stopped for a long time in a cold region. The hydraulic oil is warmed (or can be warmed).

  Therefore, in the invention of claim 1 of the present application, even when the working machine is used in a cold region, the hydraulic oil for operating the hydraulic actuator can be used in a heated state that does not hinder the operation of the hydraulic actuator. Therefore, there is an effect that when the operation of the hydraulic actuator is resumed, the hydraulic actuator can be operated immediately without any trouble.

  In the invention of claim 2 of the present application, in a hydraulically driven working machine provided with a throttle valve for controlling hydraulic oil discharged from a hydraulic actuator, a heating device for heating the hydraulic oil for operating the throttle valve is provided. Therefore, even if the hydraulic actuator is stopped for a long time in a cold region, the hydraulic oil that operates the throttle valve for controlling the hydraulic actuator is heated (or can be heated).

  Accordingly, in the invention of claim 2 of the present application, even when the working machine is used in a cold region, the hydraulic oil that operates the throttle valve is used in a heated state that does not hinder the operation of the throttle valve. Therefore, the throttle valve can be normally operated when the hydraulic actuator is operated, and there is an effect that the hydraulic actuator can perform a desired operation without any trouble.

It is use condition explanatory drawing of the bridge inspection vehicle as an example of the working vehicle carrying the working machine with a hydraulic oil heating apparatus used by this application. It is explanatory drawing of the hydraulic circuit in a working machine with a hydraulic oil heating apparatus of a present-application Example, and a heating apparatus.

  An embodiment of the present application will be described with reference to FIGS. 1 and 2. FIG. 1 shows a bridge inspection vehicle as an example of a work vehicle equipped with a working machine with a hydraulic oil heating device used in the present embodiment. Yes. In addition, as a work machine applied to the work machine with the hydraulic oil heating device of the present application, in addition to the bridge inspection machine in FIG. Machine, civil engineering machine, etc.). Therefore, for example, an aerial work vehicle, a crane work vehicle, a civil work vehicle, or the like can be employed as a work vehicle for mounting the working machine with the hydraulic oil heating device of the present application in addition to the bridge inspection vehicle of FIG.

  The bridge inspection vehicle in FIG. 1 has been proposed by the applicant of the present application and has the following configuration. That is, the bridge inspection vehicle shown in FIG. 1 has a work machine 1 for bridge inspection mounted on a vehicle 10, and the work machine 1 is provided with a swivel base 11 on the vehicle 10. A telescopic first boom 12 is attached to be able to move up and down, a telescopic second boom 13 is attached to the front end of the first boom 12 so as to be able to bend and stretched, and a lower end portion of the second boom 13 is connected via a turning device 14. A telescopic third boom 15 is attached, and a work board 16 for boarding an operator is attached to the tip of the third boom 15. The description of the detailed structure and function of the bridge inspection vehicle in FIG. 1 is omitted because it is not related to the gist of the present application.

  The work machine 1 of the bridge inspection vehicle in FIG. 1 is driven by various hydraulic actuators (such as a hydraulic cylinder and a hydraulic motor). As an example of the hydraulic actuator, a hydraulic cylinder 22 (for boom expansion and contraction and boom bending and stretching) shown in FIG. There is for). In the following embodiment, a hydraulic cylinder 22 in FIG. 2 will be described as a hydraulic actuator for a working machine.

  The hydraulic circuit in FIG. 2 can expand or contract the hydraulic cylinder 22 by switching the flow of hydraulic oil supplied from the hydraulic pump 20 with the direction switching valve 21.

  In the embodiment of FIG. 2, a throttle valve 23 is provided for controlling the hydraulic oil discharged when the hydraulic cylinder 22 is reduced. The throttle valve 23 is frequently used in a hydraulic actuator of this type of hydraulically driven working machine, and generally employs a counter balance valve. In the hydraulic circuit of FIG. 2, the operating speed of the hydraulic cylinder 22 can be adjusted by adjusting the escape amount of the discharged hydraulic oil when the hydraulic cylinder 22 is reduced by the throttle valve (counter balance valve) 23. ing.

  By the way, as a usage pattern of the bridge inspection vehicle of FIG. 1, various hydraulic actuators may be stopped for a long time in a state where the work table 16 of the work machine 1 is maintained at the bridge inspection position shown in FIG. If the hydraulic actuator has been stopped for a long time in a cold region, the hydraulic oil in the hydraulic actuator (for example, the hydraulic cylinder 22 in FIG. 2) does not move, and the hydraulic oil may drop to an abnormally low temperature. Note that when the hydraulic fluid is lowered to an abnormally low temperature, the viscosity of the hydraulic fluid is increased and the fluidity is deteriorated. As a result, the response of the hydraulic actuator is deteriorated or sometimes the hydraulic actuator cannot be operated. There is.

  Therefore, in the embodiment of the present application, as shown in FIG. 2, heating devices H1 and H2 for heating each hydraulic oil that operates the hydraulic actuator (hydraulic cylinder 22) and the control throttle valve 23 are provided. Yes.

  The heating device H1 that heats the hydraulic oil that operates the hydraulic cylinder 22 winds the heating wire 32 directly around the outer periphery of the tube of the hydraulic cylinder 22, and heats the hydraulic oil in the hydraulic cylinder 22 through the tube. It is what I did. In another embodiment, the heating device H1 (heating wire 32) for heating the hydraulic oil for operating the hydraulic cylinder 22 is located near the hydraulic cylinder 22 (for example, near the supply / discharge port of the hydraulic oil). It may be provided.

  A temperature detector 34 for detecting the hydraulic oil temperature in the hydraulic cylinder 22 is provided as an accessory to the heating device H1 on the hydraulic cylinder 22 side. The temperature detector 34 may be configured to estimate the operating oil temperature in the hydraulic cylinder 22 by detecting the temperature of the tube of the hydraulic cylinder 22.

  The detection signal detected by the temperature detector 34 on the hydraulic cylinder 22 side is input to the controller 4, and the controller 4 detects the heating wire 32 when the detected temperature detected by the temperature detector 34 falls below a predetermined lower limit temperature. And the hydraulic oil in the hydraulic cylinder 22 is controlled to be heated by heating the tube of the hydraulic cylinder 22. When the temperature detector 34 detects a predetermined upper limit temperature by heating with the heating wire 32, the power supply to the heating wire 32 is cut off by a signal from the controller 4.

  On the other hand, the heating device H2 that heats the hydraulic oil that operates the throttle valve 23 winds the heating wire 33 directly around the outside of the throttle valve 23, and operates in the throttle valve 23 via the housing of the throttle valve 23. The oil is heated. In another embodiment, the heating device H2 (heating wire 33) for heating the hydraulic oil for operating the throttle valve 23 may be provided in the hydraulic oil line near the throttle valve 23.

  A temperature detector 35 that detects the operating oil temperature in the throttle valve 23 is provided as an accessory to the heating device H2 on the throttle valve 23 side. The temperature detector 33 may be configured to estimate the operating oil temperature in the throttle valve 23 by detecting the temperature of the housing of the throttle valve 23.

  A detection signal detected by the temperature detector 35 on the throttle valve 23 side is also input to the controller 4, and the controller 4 detects the detected temperature detected by the temperature detector 35, as in the control on the hydraulic cylinder 22 side. When the temperature falls below a predetermined lower limit temperature, the heating wire 33 is energized to heat the housing of the throttle valve 23 to warm the hydraulic oil in the throttle valve 23, while the temperature detector 35 is heated by the heating wire 33 to set the predetermined upper limit temperature. When the temperature is detected, energization to the heating wire 33 is interrupted by a signal from the controller 4.

  The controller 4 functions when the work machine is in operation (the work machine operation switch is in the ON state). When the work machine is in the operation stop state (the work machine operation switch is in the OFF state), the hydraulic cylinder 22 and (Or) Even if the hydraulic oil that operates the throttle valve 23 becomes an abnormally low temperature or less, the heating action by the heating device (the heating wires 32 and 33) does not work. Therefore, when the hydraulic oil is at an abnormally low temperature or below, various hydraulic actuators may not immediately operate normally even if the work implement operation switch is turned on, but the controller 4 functions when the work implement operation switch is turned on. Therefore, the controller 4 receives the detection signals from the temperature detectors 34 and 35, and the controller 4 transmits a signal for energizing the heating wires 32 and 33. The temperature can be increased to a temperature at which the hydraulic actuator operates normally.

  The working machine with the hydraulic oil heating device of this embodiment functions as follows. That is, when a work vehicle (for example, a bridge inspection vehicle in FIG. 1) equipped with this work machine is used in a cold region, the operation is performed with the hydraulic actuator stopped for a long time, as shown in FIG. The hydraulic oil that operates the hydraulic cylinder 22 and its throttle valve 23 may drop to an abnormally low temperature or lower, but when the hydraulic oil drops to an allowable set temperature, detection from temperature detectors 34 and 35 that detect the temperature. In response to the signal, the controller 4 energizes the heating wires 32 and 33 to heat the hydraulic oil.

  As described above, in the working machine using the hydraulic oil heating device according to the embodiment of the present invention, the hydraulic oil for operating the hydraulic actuator (hydraulic cylinder 22) and the throttle valve 23 is always used even when the working machine is used in a cold region. Since it can be used in a predetermined heating state, when the operation of the hydraulic actuator is resumed from the operation stop state, the hydraulic actuator can be immediately operated without any trouble. Therefore, even when the working machine is used in a cold region, various troubles (deterioration of working efficiency, inability to operate the hydraulic actuator, etc.) due to the abnormal temperature of the hydraulic oil can be solved.

  1 is a hydraulically driven working machine, H1 and H2 are heating devices, 4 is a controller, 22 is a hydraulic cylinder (hydraulic actuator), 23 is a throttle valve, 32 and 33 are heating wires, and 34 and 35 are temperature detectors. is there.

Claims (2)

A hydraulically driven working machine driven by a hydraulic actuator,
A heating device for heating the hydraulic oil that operates the hydraulic actuator is provided at a position near the hydraulic actuator itself or the hydraulic actuator.
A working machine equipped with a hydraulic oil heating device. A hydraulically driven working machine including a throttle valve that is driven by a hydraulic actuator and controls hydraulic oil discharged from the hydraulic actuator,
A heating device for heating the hydraulic oil for operating the throttle valve is provided at the throttle valve itself or in the vicinity of the throttle valve,
A working machine equipped with a hydraulic oil heating device.

Images