JP2014114545A - Hydraulic unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic unit with a control function capable of continuing operation safely by effectively preventing overheating of an engine and a rise in temperature of hydraulic oil.SOLUTION: A hydraulic unit controller 17 which controls a hydraulic unit includes: temperature detection means (a water temperature sensor 18 and a water temperature switch 19) of detecting the temperature of cooling water of an engine; first warning generation means of generating a first temperature rise warning when the detected temperature of the temperature detection means rises above a preset first set temperature; and second warning generation means of generating a second temperature rise warning different from the first temperature rise warning when the detected temperature of the temperature detection means rises above a preset second set temperature higher than the first set temperature.

Description

  The present invention relates to a hydraulic unit, and more particularly, to a hydraulic unit suitable for supplying hydraulic oil (pressure oil) boosted by driving a hydraulic pump with an engine as a drive source of a full-rotation tubing device.

  Various working devices used at construction sites, such as cranes and pile driving machines equipped with traveling means, power shovels (hydraulic excavators), etc., are hydraulic pumps with engines as drive sources for hydraulic actuators such as hydraulic motors and hydraulic cylinders. A full-rotation tubing device that is equipped with a hydraulic unit that drives the vehicle and that does not have traveling means is configured to receive hydraulic oil supplied from a separately formed engine-driven hydraulic unit via a hydraulic hose. Yes.

  As a safety device in such a hydraulic unit, the engine coolant temperature and hydraulic oil temperature are monitored, and when these temperatures rise, the discharge amount of the hydraulic pump is reduced to avoid engine overheating. A safety device that protects various devices provided in a hydraulic circuit is known (see, for example, Patent Document 1).

JP-A-6-248666

  The safety device described in Patent Document 1 can exhibit a sufficient effect for a hydraulic unit that supplies hydraulic oil to a hydraulic cylinder as exemplified in Patent Document 1, and for a crane. A sufficient effect can be expected even in a hydraulic motor that operates a winch. However, in a full-rotation tubing device that press-fits while rotating a large-diameter casing tube, the rotational resistance and rotational reaction force of the casing tube are large, and furthermore, it varies depending on the diameter of the casing tube, the depth of press-fit, and the state of earth and sand. Therefore, if the discharge amount of the hydraulic pump is simply reduced due to the temperature rise of the engine cooling water, the casing tube may not continue to rotate.

  In particular, the situation where the engine is overheated by a high load is a situation where the casing tube has a large rotational resistance and a large amount of hydraulic oil is continuously supplied to the hydraulic motor to rotate the casing tube. When the rotation of the casing tube stops, the earth and sand in the ground sticks to the casing tube, and the rotation resistance becomes larger, which may make it very difficult to restart. Further, when the temperature of the hydraulic oil rises, there is a possibility that the oil pump is cut off and the operation cannot be continued.

  In view of this, the present invention provides a control that can safely continue work by effectively preventing engine overheating and hydraulic oil temperature rise for work requiring high load operation such as rotary press-fitting of a casing tube. The object is to provide a hydraulic unit having a function.

  In order to achieve the above object, a hydraulic unit according to the present invention is a hydraulic unit that drives a variable displacement hydraulic pump with an engine and supplies hydraulic oil boosted by the variable displacement hydraulic pump as a drive source of a hydraulic actuator. A hydraulic unit controller that controls the temperature of the cooling water of the engine, and a first temperature rise when the detected temperature of the temperature detection means is equal to or higher than a preset first set temperature. The first alarm generation means for issuing an alarm and the first temperature increase alarm when the temperature detected by the temperature detection means is equal to or higher than a second set temperature set higher than the first set temperature. And a second alarm generation means for issuing a different second temperature rise alarm.

  Furthermore, the hydraulic unit according to the present invention includes a temperature detection means for detecting the temperature of the hydraulic oil, and a temperature rise of the hydraulic oil when the temperature detected by the temperature detection means becomes equal to or higher than a preset temperature of the hydraulic oil. An alarm generating means for issuing an alarm is provided.

  According to the hydraulic unit of the present invention, when the temperature of the cooling water is equal to or higher than the first set temperature set lower than the second set temperature, the first temperature rise alarm is issued to cope with the temperature rise. Since the operator is urged to perform the operation, the operator reduces the engine load by performing low-load operation such as reducing the discharge amount of the variable displacement hydraulic pump while checking the status of the hydraulic oil supply destination, and cooling The temperature of the water can be lowered, and the operation can be continued while avoiding the stop of the engine due to overheating.

  In addition, even if the low temperature operation is performed with the first temperature rise alarm, when the temperature of the cooling water or the hydraulic oil rises to be equal to or higher than the second set temperature, a second temperature rise alarm different from the first temperature rise alarm is obtained. Is issued, and it is strongly urged to perform the operation with a lower load, and the operation can be continued by suppressing the temperature rise more reliably. This makes it possible to reliably and continuously supply hydraulic oil to applications where interruption of work is not desirable, such as a full-rotation tubing device that rotationally press-fits a casing tube. Can be carried out safely and continuously. Furthermore, by detecting an increase in the temperature of the hydraulic oil and issuing an alarm, it is possible to reliably prevent the occurrence of an oil film break due to the increase in the hydraulic oil temperature.

It is explanatory drawing which shows the example of 1 form of the hydraulic unit of this invention. It is a flowchart which shows an example of the procedure which monitors the temperature rise of the cooling water at the time of a driving | operation, and hydraulic fluid.

  The hydraulic unit shown in the present embodiment includes an engine 11 serving as a drive source, a variable displacement hydraulic pump 12 driven by the engine 11, and hydraulic oil boosted by the variable displacement hydraulic pump 12 with a control valve 13 and a relief valve. 14 and a hydraulic circuit 15 that supplies a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder via 14, an engine controller (engine work machine) 16 that controls the engine, a variable displacement hydraulic pump 12, and a control valve 13. And a hydraulic unit controller 17 for controlling the above.

  Further, the engine 11 is provided with a water temperature sensor 18 for displaying the temperature of the cooling water on the engine controller 16, and a temperature detecting means for operating the hydraulic unit controller 17 according to the temperature of the cooling water. A water temperature switch 19 is provided. Further, the discharge path 12a of the variable displacement hydraulic pump 12 is provided with an oil temperature switch 20 serving as a temperature detecting means for operating the hydraulic unit controller 17 in accordance with the increased temperature of the hydraulic oil.

  The hydraulic unit controller 17 controls the variable displacement hydraulic pump 12 and the control valve 13 by the operation of the operator, controls the pressure, flow rate and direction, and supplies the hydraulic oil to the hydraulic actuator. In addition, the water temperature switch 19 And a temperature control unit for monitoring the temperature rise of the cooling water and hydraulic oil during operation by a signal from the oil temperature switch 20 and preventing the engine and the like from being stopped due to the temperature rise of the cooling water and hydraulic oil. Yes.

  This temperature control unit monitors the temperature of the cooling water and hydraulic oil during operation (overheat monitoring) according to the procedure shown in FIG. 2, and gives a predetermined alarm when the temperature of the cooling water or hydraulic oil rises. By informing the operator of the temperature rise and prompting the operator to perform a low load operation, the hydraulic unit is prevented from being stopped due to the temperature rise of the cooling water or hydraulic oil.

  First, engine cooling water temperature monitoring starts from step 51, and whether the engine cooling water temperature detected by the water temperature switch 19 in step 52 has risen to a first set temperature of the cooling water, for example, 100 ° C. or higher. If the temperature of the cooling water has not risen to 100 ° C. or higher, the process returns to the first step 51 and the operation is continued as it is. If it is determined in step 52 that the temperature of the cooling water has risen to 100 ° C. or higher, the process proceeds to step 53 where the first alarm generation means is activated to sound a first temperature increase alarm, for example, a buzzer, or a warning lamp. , Etc., to notify the operator of a temperature rise warning and to encourage low-load operation. While the first temperature rise warning is issued, in step 54, the operator confirms the state of the hydraulic actuator that supplies hydraulic oil from the hydraulic unit, for example, the hydraulic motor for rotary press-fitting of the casing tube in the full-rotation tubing device. A low-load operation is performed to reduce the engine load by reducing the discharge amount while keeping the discharge pressure of the displacement hydraulic pump 12 constant, and the rotational speed is lowered while keeping the rotation torque of the casing tube by the hydraulic motor constant. To continue working.

  During low-load operation, the first temperature rise alarm continues, and in the next step 55, it is determined whether the temperature of the cooling water has dropped below 100 ° C, and the temperature of the cooling water has dropped below 100 ° C. If so, the first temperature rise alarm is stopped and the routine returns to the first step 51 to resume normal work. If the temperature of the cooling water has not dropped below 100 ° C., the process proceeds from step 55 to step 56, where the temperature of the cooling water monitored by the engine controller and detected by the water temperature sensor 18 is a second set temperature, for example, 105 ° C. It is determined whether or not it has risen above. When the temperature of the cooling water has not risen to 105 ° C. or higher, the flow returns to step 54 to continue the low load operation, and the discharge amount of the variable displacement hydraulic pump 12 is further reduced as necessary.

  When it is determined in step 56 that the temperature of the cooling water has risen to 105 ° C. or higher, the routine proceeds to step 57, where the second alarm generating means is operated. A second temperature rise warning is issued which is a stronger warning than the first temperature rise warning. For the second temperature increase alarm stronger than the first temperature increase alarm, for example, an appropriate combination of red for yellow and buzzer volume can be selected. When the second temperature rise warning is issued, the operator reduces the discharge pressure, that is, the output torque, of the variable displacement hydraulic pump 12 to the extent that the rotation of the casing tube does not stop while checking the rotation state of the casing tube. Do low-load operation to reduce the load. During the low load operation in step 57, as in step 54, the determination of the temperature of the cooling water in steps 55 and 56 is repeated, and it is determined in step 55 that the temperature of the cooling water has dropped below 100 ° C. When this happens, all alarms are released and the process returns to step 51 to return to the normal working state.

  In this way, an alarm is issued in response to the temperature rise of the cooling water, prompting the operator to perform a low load operation, and adjusting the discharge pressure and flow rate of the variable displacement hydraulic pump 12 to such an extent that the operator does not interrupt the work. By doing so, the engine will not overheat and stop suddenly, and the work can be continued safely.

  The temperature monitoring of the hydraulic oil starts from step 61, and it is determined whether or not the temperature of the hydraulic oil detected by the oil temperature switch 20 in step 62 has risen to a set temperature of the hydraulic oil, for example, 80 ° C. or higher. If the temperature of the hydraulic oil has not risen above 80 ° C., the process returns to the first step 61. When it is determined in step 62 that the temperature of the hydraulic oil has risen to 80 ° C. or higher, the routine proceeds to step 63, where an alarm generating means similar to the monitoring of the cooling water temperature is activated to issue a hydraulic oil temperature increase alarm. The operator is notified of the temperature rise warning and urged to perform low-load operation. During the temperature rise warning issuance, in step 64, the operator adjusts the discharge pressure and discharge amount of the variable displacement hydraulic pump 12 to perform low load operation and reduce the flow rate of the hydraulic oil as described above. To lower the temperature. In this way, by monitoring the temperature of the hydraulic oil and performing low-load operation when the temperature rises, it is possible to avoid the occurrence of oil film breakage due to the rise in the temperature of the hydraulic oil, Can continue safely.

  In the procedure of FIG. 2, the determination at the second set temperature is performed using the water temperature sensor provided in the engine controller. However, a plurality of water temperature switches with different settings may be used as a determination standard. . Further, a procedure that does not monitor the temperature rise of the hydraulic oil can be adopted.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Variable displacement hydraulic pump, 12a ... Discharge path, 13 ... Control valve, 14 ... Relief valve, 15 ... Hydraulic circuit, 16 ... Engine controller, 17 ... Hydraulic unit controller, 18 ... Water temperature sensor, 19 ... Water temperature switch, 20 ... Oil temperature switch

Claims (2)

  In a hydraulic unit that drives a variable displacement hydraulic pump by an engine and supplies hydraulic oil boosted by the variable displacement hydraulic pump as a drive source of a hydraulic actuator, a hydraulic unit controller that controls the hydraulic unit includes cooling water for the engine Temperature detection means for detecting the temperature of the first temperature, first alarm generation means for issuing a first temperature rise alarm when the temperature detected by the temperature detection means is equal to or higher than a preset first set temperature, and the temperature detection means Second alarm generating means for issuing a second temperature increase alarm different from the first temperature increase alarm when a detected temperature of the first temperature becomes equal to or higher than a second set temperature set higher than the first set temperature. A hydraulic unit comprising:   Temperature detection means for detecting the temperature of the hydraulic oil; and alarm generation means for issuing a temperature rise warning for the hydraulic oil when the temperature detected by the temperature detection means is equal to or higher than a preset temperature of the hydraulic oil. The hydraulic unit according to claim 1, wherein:

Images