JP2014062469A - Hydraulic pump control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an engine to be easily started up at a low temperature.SOLUTION: A hydraulic pump control device comprises: a plurality of hydraulic pumps which are driven by power of an engine 3; a clutch 50 which is arranged at an input shaft side of a lifting pump 45, one of the plurality of hydraulic pumps serving as a working hydraulic pump, and connects or disconnects the power; a water temperature sensor 90 which detects a temperature relevant to the engine 3; a motor 51 which serves as an actuator to operate the clutch 50; and control means 60 which controls the motor 51 serving as the actuator. The control means 60 operates the motor 51 serving as the actuator and disengages the clutch when a detected value of temperature detection means indicates a low temperature equal to or lower than a set temperature.

Description

  The present invention relates to a technique for improving startability of an engine mounted on a work vehicle at a low temperature.

In a working vehicle in which a hydraulic pump is connected to the output shaft of the engine, if the ambient temperature is low, such as in winter, the viscosity of the hydraulic oil increases, and the load at the start of the engine increases, which may make starting difficult. In order to improve the startability at such a low temperature, various measures have been conventionally taken. For example, a bypass oil passage is arranged between the discharge port of the hydraulic pump and the hydraulic device and connected via a three-way switching valve, the other side of the bypass oil passage is connected to a hydraulic oil tank, and the temperature is lower than the set temperature when starting the engine. In this case, the three-way switching valve is switched to the bypass oil passage side to reduce the resistance of the hydraulic pump (see Patent Document 1).
Also known is a technique in which the hydraulic pump is of a variable displacement type, the angle of the swash plate can be changed by a flow rate control regulator, and the tilt angle of the hydraulic pump is controlled to the minimum by the flow rate control regulator when the engine is started ( Patent Document 2).

JP-A-6-129359 JP 2008-151111 A

However, in the case of the technique disclosed in Patent Document 1, a bypass oil passage and a three-way switching valve are required, which increases the number of parts, and it is necessary to separately pipe the bypass oil passage. In the case of the techniques disclosed in Patent Documents 1 and 2, since the hydraulic pump is always connected, there is a limit to the reduction of the load at the time of starting.
The present invention has been made in view of the above situation, and makes it possible to easily start an engine at a low temperature.

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
That is, in claim 1, a plurality of hydraulic pumps driven by power from the engine, a clutch arranged on the input shaft side of the working hydraulic pump among the plurality of hydraulic pumps to connect and disconnect the power, A temperature detecting means for detecting a temperature related to the engine; an actuator for operating the clutch; and a control means for controlling the actuator, wherein the control means has a detection value at a low temperature equal to or lower than a set temperature. In this case, when starting the engine, the actuator is operated to disengage the clutch.

According to a second aspect of the present invention, load detecting means is provided in the control means, and after the engine is started, the control means operates the actuator to engage the clutch when the engine load becomes a set value or less. ".
According to a third aspect of the present invention, an engine speed detecting means is provided in the control means, and after the engine is started, the control means operates the actuator when the engine speed becomes equal to or higher than a set speed to The clutch is set to “contact”.

According to a fourth aspect of the present invention, the control means is provided with a load detection means and a rotation speed detection means. After the engine is started, the control means is configured such that the engine load is not more than a set value and the engine rotation speed is a set rotation speed. When the above is reached, the actuator is operated to bring the clutch into “contact”.
According to a fifth aspect of the present invention, after the engine is started, the control means operates the actuator to bring the clutch into “contact” when the detected value of the temperature detecting means becomes equal to or higher than a set temperature. .

In claim 6, the control means is connected to the lift position detection means of the work implement, the lifting operation position detection means, and a control valve for switching oil supply to the hydraulic actuator, and when the clutch is "contact", The control means detects and compares the lift position and the lift operation position of the work implement, and stops the operation of the control valve that controls the hydraulic actuator when the lift position does not match the operation position.
According to a seventh aspect of the present invention, the control means is connected to a lift position detecting means, a lifting operation position detecting means and a hydraulic actuator control valve of a work implement, and when the clutch is “contacted”, the control means The lift position and the lift operation position are detected and compared, and if the lift position and the operation position do not match, the lift lowering operation by the hydraulic actuator is prohibited and the lift operation is permitted.

In an eighth aspect of the present invention, the temperature detecting means detects a cooling water temperature or a lubricating oil temperature.
According to a ninth aspect of the present invention, the control means is connected to a low temperature start control selection means for selecting execution or non-execution of the low temperature engine start control so that the low temperature engine start control can be arbitrarily selected.

As effects of the present invention, the following effects can be obtained.
When starting the engine at a low temperature, the hydraulic pump as a load is disconnected, so that the starting load is reduced and the engine can be started easily.

The side view of a tractor provided with the hydraulic pump control device of the present invention. The side view of an engine and a mission case. Schematic which shows a hydraulic circuit structure. The side view of the connection / disconnection operation mechanism of a clutch. The perspective view which shows the connection / disconnection operation mechanism of a clutch. Control block diagram. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. The front-rear direction is defined with the arrow F direction as the front direction.
The work vehicle according to the present invention will be described from the overall configuration as a crawler tractor 1. The crawler tractor 1 is provided with a lifting / lowering connection mechanism 2 for the working machine at the rear, and is configured to be able to be lifted / lowered by connecting various working machines via the lifting / lowering connection mechanism 2.

  In the crawler tractor 1, an engine 3 is disposed as a prime mover at a front portion on a vehicle body frame 7, and an operation unit 4 is disposed at a rear position of the engine 3. The driving unit 4 is covered with a cabin 5, and a steering wheel, a seat, a transmission lever that serves as an operation means 95, a PTO lever, a lift lever, and the like (not shown) are disposed in the cabin 5.

  The vehicle body frame 7 is supported by a traveling unit 6, and the traveling unit 6 has driving wheels 11 attached to a front end portion of a traveling frame 10 extending in the front-rear direction via a front transmission case 25 described later. On the other hand, a driven wheel 12 is attached to the rear end of the traveling frame 10, and a crawler belt 14 is wound between the driving wheel 11 and the driven wheel 12. An upper rolling wheel 15 is disposed at the upper center of the traveling frame 10, and equalizers 16 and 16 are disposed at the lower portion of the traveling frame 10.

  As shown in FIG. 2, a front gear case 30 is disposed at a front position of the engine 3 to transmit power via a transmission shaft and a universal joint, and a turning HST (hydrostatic non-hydraulic type) is provided on the output side of the front gear case 30. The input side of the front transmission case 25 is linked and connected to the output side of the turning HST 32.

  A traveling HST (hydrostatic continuously variable transmission) 34 is linked to the rear position of the engine 3 via a rear gear case 33, and the input side of the rear mission case 36 is linked to the output side of the traveling HST 34. ing. Further, the front transmission side of the rear transmission case 36 is linked to the input side of the front transmission case 25 via a transmission shaft and a universal joint so that power for turning from the front gear case 30 can be synthesized. On the other hand, another output side of the rear gear case 33 is interlocked with a sub gear case 47 provided in the rear mission case 36, and the PTO shaft 38 is projected rearward from the sub gear case 47.

  A plurality of hydraulic pumps are connected to the output shaft of the engine 3 through a gear case, and are driven simultaneously when the engine 3 is started. More specifically, as shown in FIG. 3, power is transmitted from the front output shaft of the engine 3 to the front gear case 30, and the variable pump 40 and the charge pump 41 of the turning HST 32 that are linked to the front gear case 30. Is driven. On the other hand, power is transmitted from the rear output shaft of the engine 3 to the rear gear case 33, and the variable pump 42, the charge pump 43, the transfer lubrication pump 44, and the lift lubrication pump 44 of the traveling HST 34, which are linked to the rear gear case 33, The pump 45 and the PTO clutch pump 46 are driven. However, when only one lift pump 45 is driven from the engine 3, for example, it is also possible to drive it directly connected without a gear case.

  The variable pump 40, charge pump 41, variable pump 42, charge pump 43, transfer lubrication pump 44, lift pump 45, and PTO clutch lubrication pump 46 are driven when the engine 3 is started. Since 40 and the variable pump 42 do not run at the same time as starting the engine, they are operated (or controlled) to the neutral position and are in a light load state in which no pressure oil is fed. Among a plurality of other fixed displacement pumps, the hydraulic pump having the largest capacity is a lift pump 45 for work, and a power connection / disconnection clutch 50 is interposed on the input shaft 45a. However, in an atmosphere below the set temperature, the clutch 50 is controlled to be “disengaged” to reduce the load when starting the engine so that it can be started easily.

  That is, in the present embodiment, the lift pump 45 has the largest capacity among the fixed capacity pumps connected to the gear case. A clutch 50 is interposed between the input shaft 45a of the lift pump 45 and the output shaft 33a of the rear gear case 33, and the clutch 50 is "disconnected" or "contacted" by the operation of a motor 51 serving as an actuator. The motor 51 is connected to the control means 60 and controlled.

  Power is transmitted to the output gear 33a of the rear gear case 33 to the sub gear case 47 via a transmission shaft and a universal joint. The sub-gear case 47 is attached to the rear transmission case 36. The sub-gear case 47 is provided with a lift pump 45 for operating a working hydraulic actuator via a clutch 50, and a PTO clutch pump 46 is attached in parallel. .

A lift control valve 48, an inclination control valve 49, and a sub control valve 58 are connected to the discharge side of the lift pump 45 through a diversion valve 57. A lift cylinder 52 serving as a hydraulic actuator is connected to the elevation control valve 48 via a pipe, an inclination cylinder 53 is connected to the inclination control valve 49 via a pipe, and a sub control valve 58 is connected to the sub control valve 58 in this embodiment. Although not provided, it can be connected to a hydraulic actuator such as a front loader or mower. The elevation control valve 48, the inclination control valve 49, and the sub control valve 58 are composed of electromagnetic valves, and the solenoids of the elevation control valve 48, the inclination control valve 49, and the sub control valve 58 are connected to the control means 60 (see FIG. 6). ).
The lift control valve 48 is switched by the operation of the lift lever of the operation unit 4 and the lift cylinder 52 is expanded and contracted, so that the work machine (rotary tillage device) connected to the lift connection mechanism 2 can be lifted and lowered to a desired height. When the tilling device is controlled in depth, the lift cylinder 52 is driven to extend and contract so as to reach the set depth. In addition, when the tilt control valve 49 is switched by operating the tilt angle setting dial of the operation unit 4 and the tilt cylinder 53 is expanded and contracted, the tilt cylinder 53 can be tilted to a desired tilt angle, and the aircraft is controlled horizontally. When tilted, the tilt control valve 49 is switched and the tilt cylinder 53 is extended and retracted to control the work implement to be horizontal. The sub control valve 58 is a hydraulic valve for external take-off. When an attachment such as a front loader is mounted, the sub control valve 58 is connected to a hydraulic actuator such as a hydraulic cylinder or a hydraulic motor via a pipe at the output port of the sub control valve 58. Thus, the attachment can be operated by switching the sub control valve 58.

  The discharge side of the PTO clutch pump 46 is connected to a PTO clutch 55 and a lubricating oil passage 56 via a PTO switching valve 54. The PTO switching valve 54 is composed of an electromagnetic valve, and the solenoid of the PTO switching valve 54 is connected to the control means 60. When the engine 3 is operated, the PTO clutch pump 46 is driven, and when the PTO “ON” operation of the operation unit 4 is performed, the PTO switching valve 54 is switched and pressure oil is fed to the PTO clutch 55. The PTO clutch 55 is “contacted”, the PTO shaft 38 is rotationally driven, and the excess pressure oil is sent to the lubricating oil passage 56. When the PTO “disconnect” operation is performed, the PTO switching valve 54 is switched and the PTO clutch 55 is disengaged.

Next, a configuration for operating the clutch 50 by the motor 51 will be described with reference to FIGS.
A clutch case 70 that houses the clutch 50 is fixed to the front surface of the sub gear case 47, and a lift pump 45 is fixed to the front surface of the clutch case 70. A clutch shaft 71 for connecting and disconnecting the clutch 50 is projected upward from the upper surface of the clutch case 70, and one end of a clutch arm 72 is fixed to the upper portion of the clutch shaft 71. A roller 74 that is in contact with the operation cam 73 is rotatably supported on the upper end of the other end of the clutch arm 72.
The clutch 50 is composed of a multi-plate clutch, and is normally “contacted” (when the actuator is not actuated). The friction plate provided on the output shaft 47a of the sub gear case 47 and the input shaft 45a of the lift pump 45 (see FIG. 3) The friction plate provided on the upper surface is pressed by an urging member such as a spring to transmit power. When the clutch arm 72 is rotated by the operation of the actuator and the clutch shaft 71 is rotated, the fork provided on the clutch shaft 71 in the clutch case 70 is rotated, and the friction plate and the input shaft on the output shaft 47a are rotated. The friction plate on 45a is separated and the transmission of power is cut off, resulting in a “break”. However, the clutch 50 is not limited to the friction plate type, and may be a meshing type or the like.

  The operation cam 73 is eccentrically fixed to the lower end of the cam shaft 76, and the operation cam 73 is disposed at substantially the same height as the roller 74 so as to be in contact with the outer peripheral surface of the roller 74. The cam shaft 76 is supported by a support boss 83 in the middle of the upper and lower portions, and the support boss 83 is supported by a bracket 75 fixed on the clutch case 70 via a support stay 84. The upper part of the cam shaft 76 is linked to the motor 51 via the position adjusting unit 61 and the reduction gear box 85. However, the motor 51 can be directly driven without providing the reduction gear box 85. Thus, when the cam shaft 76 is rotated via the position adjustment unit 61 by the operation of the motor 51, the operation cam 73 is rotated, the clutch arm 72 is rotated via the roller 74, and the clutch 50 is turned "off". be able to.

  The position adjusting unit 61 interposed between the cam shaft 76 and the motor 51 is caused by an assembly error or the like between the output shaft 85a of the reduction gear box 85 to which the output of the motor 51 is transmitted and the cam shaft 76. It is intended to absorb the generated shaft misalignment, eliminates assembly adjustment work, and allows the cam shaft 76 to rotate smoothly without applying excessive force during operation.

The position adjustment unit 61 includes a first arm 77 whose one end is fixed to the upper part of the cam shaft 76, a second arm 78 whose one end is fixed to the lower part of the output shaft 85a, the other end of the first arm 77, and a second arm. The arm 78 includes a pin 79 that connects the other end of the arm 78. The first arm 77 and the second arm 78 are configured to have substantially the same length, and a long hole 77a is opened at the other end of the first arm 77 in parallel with the longitudinal direction. It is provided to project.
When the position adjustment unit 61 is assembled, the reduction gear box 85 (motor 51) is fixed to the bracket 75 so that the output shaft 85a is substantially aligned with the shaft center above the cam shaft 76, and the pin 79 is inserted into the long hole 77a. By inserting, the first arm 77 and the second arm 78 are connected. However, the first arm 77 may be provided with a pin 79 and the second arm 78 may be provided with a long hole.
Thus, even if the shaft centers of the cam shaft 76 and the output shaft 51a are slightly displaced, the pin 79 can move within the elongated hole 77a to absorb the error, and the motor 51 is operated to rotate the output shaft 85a. In this case, the cam shaft 76 can be rotated in a substantially synchronized manner without applying an excessive force.

Further, a manual operation means 62 is provided in the vicinity of the operation cam 73, which can manually turn the clutch arm 72 to make the clutch 50 "disengaged" in the event of a failure or abnormality in the motor 51. .
The manual operation means 62 includes a release arm 80 disposed so as to be able to contact the side surface of the clutch arm 72, an arm shaft 81 that fixes one end of the release arm 80, and an upper portion of the arm shaft 81 when rotating. The upper support plate 82 and the like are supported freely. The manual operation means 62 is disposed on the side of the clutch arm 72 on the same side as the operation cam 73 on the bracket 75. The arm shaft 81 is rotatably supported by a support hole having a lower portion opened in the bracket 75, and an upper portion is rotatably supported by the tip of the upper support plate 82. An operation hole 81a is opened through the arm shaft 81 in the diameter (horizontal) direction in the middle of the upper and lower sides. The operation hole 81a is configured to have a size capable of inserting a tool such as a screwdriver. One end of the release arm 80 is fixed to the lower portion of the operation hole 81a, and the release arm 80 and the clutch arm 72 are arranged close to each other at substantially the same height.
Thus, in the event of an emergency such as when the motor 51 fails, the clutch 50 cannot be switched to “disengaged” and the engine 3 cannot be started, and a driver or the like is inserted into the operation hole 81a to By manually rotating 81, the release arm 80 is rotated, the distal end side surface of the release arm 80 is pressed against the side surface of the clutch arm 72, the clutch arm 72 is rotated, and the clutch 50 is disconnected. ". Therefore, by manually rotating the arm shaft 81 when starting the engine, the lift pump 45 is not driven, the load is reduced, and the engine 3 can be started easily.

  In addition, a delay mechanism is provided between the clutch 50 and the operation cam 73 so as to gradually “contact” the clutch 50. This delay mechanism is determined by the outer shape of the outer periphery where the operation cam 73 contacts the clutch arm 72 (profile shape of the operation cam 73). That is, the radius of the contact portion of the operation cam 73 is gradually reduced in the rotation range of the operation cam 73 from “disengagement” to “contact” of the clutch 50, and a portion serving as a half-clutch is provided. As a result, the lift pump 45 is prevented from suddenly rotating. That is, it is possible to prevent the engine 3 from being subjected to a large load or an impact when the clutch 50 is “contacted”. In the delay mechanism, instead of the configuration in which the profile shape of the operation cam 73 is changed, the return spring serving as a biasing member that presses the friction plate of the clutch 50 is doubled or a plurality of springs having different spring forces are combined. Can also be configured.

Further, instead of providing the operation cam 73 with the delay mechanism of the clutch 50, the control means 60 for controlling the motor 51 may be provided with a delay means 60a for gradually making the clutch "contact". In other words, the delay means 60a reduces the rotational speed of the motor 51 by reducing the rotational speed per hour of the motor 51 in order to gradually “contact” the clutch 50.
Thus, the clutch 50 is not suddenly “contacted”, the lift pump 45 is not suddenly actuated, and the lift cylinder 52 is suddenly actuated even when the operating means 95 is operated to the ascending side. Will not rise.

Next, the control configuration will be described with reference to FIG.
The motor 51 serving as the actuator serves as a drive source for switching the clutch 50 and is connected to and controlled by the control means 60.
The control means 60 is connected to temperature detection means for detecting the temperature related to the engine 3. The temperature related to the engine 3 refers to the temperature of the engine 3, the temperature of a generator, a hydraulic pump, a cooling pump, a governor, a controller, etc. as accessories attached to the engine 3, the ambient temperature of the engine, and the transmission linked to the engine 3 And the temperature of a power transmission member such as a gear case. The temperature of the engine 3 includes the temperature of the cooling water, the temperature of the lubricating oil, the intake air temperature, the exhaust gas temperature, the supply fuel temperature, the oil pan surface temperature, and the like. A water temperature sensor 90 that detects the cooling water temperature is connected to the control means 60 as the temperature detection means of the present embodiment.

The control means 60 is connected to a rotational speed sensor 91 that serves as a rotational speed detection means of the engine 3. The control means 60 controls the clutch 50 to be “engaged” when the engine speed becomes equal to or higher than the release setting speed during the low temperature start control. The release setting rotation speed can be changed by a cancellation setting rotation speed changing means 92 connected to the control means 60.
A display means 93 is connected to the control means 60. The display means 93 displays the engine speed, an error, etc., and indicates the value of the release setting speed and whether or not the low temperature start control is being performed (or whether the clutch 50 is “disconnected” or “contacted”). indicate. The display means 93 is provided in the operation unit 4. Thus, the operator can easily recognize whether or not the cold start control is being performed, and can easily recognize that the hydraulic lift or the work machine cannot be operated when the cold start control is being performed.
Connected to the control means 60 is a cold start control selection means 96 for selecting whether to execute or prohibit the cold start control. When it is desired to operate the work implement simultaneously with the engine start or when the work implement is to be raised or lowered, the low temperature start control selection means 96 is turned off.

The control means 60 is connected to a start switch 97 and a cell motor 98 which are constituted by a key switch or the like serving as an engine start means. When starting the engine 3, the start switch 97 is operated to activate the cell motor 98. After the engine is started, the control means 60 controls a fuel injection device (not shown) and the like so as to achieve a set rotational speed set by the operator.
The control means 60 is provided with a load detection means 60b, which controls the fuel injection amount so as to reach a set rotational speed according to the load increase / decrease. The load can be calculated from the difference between the set rotational speed and the actual rotational speed, and the load detecting means is not limited.

An operation means 95 is connected to the control means 60. The operation means 95 includes a rotation speed setting lever (accelerator), a speed change lever, a PTO lever, a lifting lever, a tilling depth setting dial, an inclination angle setting dial, etc. Input to means 95.
The control means 60 is connected to the elevation control valve 48, the inclination control valve 49, the PTO switching valve 54, and the sub control valve 58, and is switched according to the operation of the operation means 95 provided in the operation unit 4.
The control means 60 is connected to a lift position sensor 99 that detects the position of the lift arm, and the control means 60 switches the elevation control valve 48 so that the position (height) set by the operation means 95 is reached.
The control means 60 is connected to an inclination sensor 94 that detects the inclination of the work implement, and the control means 60 switches the inclination control valve 49 so that the inclination set by the operation means 95 is obtained.

Next, the cold start control will be described with reference to FIG.
When the start switch 97 is turned on to start the engine 3 (S1), the operation means 95 determines whether or not the low temperature start control selection means 96 is switched on (execution) (S2). Activates the cell motor 98 to start the engine 3 (S3). If the temperature is low at this time, the engine may not be started. After the start, normal rotation speed control is performed so that the set rotation is achieved (S3).

In step S2, when it is ON (low temperature start control is performed), the process proceeds to step S11, the water temperature T1 is detected by the water temperature sensor 90 (S11), and it is determined whether the water temperature T1 is equal to or higher than the set temperature T0 (S12). In addition, it is not limited to water temperature, You may determine whether it is low temperature by detecting oil temperature (lubricating oil or hydraulic oil), ambient temperature, etc. When the water temperature T1 is equal to or higher than the set value T0, the cell motor 98 is operated to start the engine 3 (S13), and the load is detected (S14). It is determined whether or not the load is equal to or greater than the set value (S15). If the load is equal to or greater than the set value, the motor 51 is operated to set the clutch 50 to “disengaged” (S16), and the process returns to Step 14. When the load is less than the set value, the clutch 50 is set to “contact” (S17), and normal engine operation control is performed (S18).
This is because when the engine is about to be stalled due to overload during work, for example, when it reaches a climbing slope during towing work or control work, or when it is deeply plowed during plowing work, etc. As a result, the driving of the lift pump 45 can be stopped, and the power can be used for traveling and work, and the engine stall can be avoided.

In step 12, when the water temperature T1 is not equal to or higher than the set value T0 (the water temperature T1 is lower than the set value T0), it is determined that the temperature is low, the motor 51 is operated, the clutch 50 is turned off (S21), and the cell motor 98 is operated. The engine 3 is started (S22).
Then, after the engine 3 is started, the current engine speed N1 and the release setting speed N for canceling the low temperature start control are read (S23), and the speed N1 is compared with the release setting speed N (S24). ) When the rotational speed N1 is less than the release setting rotational speed N, the engine 3 is not warmed and the load is large. Therefore, the engine 3 is operated with the clutch 50 disengaged, and the rotational speed N1 is the release setting rotational speed. When the number is greater than the number N, the clutch 50 is set to “contact” (S25), and the engine 3 is controlled to perform normal operation (S26). The release setting rotation speed can be changed by the release setting rotation speed changing means 92, and is set to the idle rotation speed in the present embodiment. That is, when the engine speed increases to the idling speed, the engine 3 is normally operated with the clutch 50 set to “contact”. However, instead of setting the rotation speed as a target for switching determination of the clutch 50, the water temperature, the oil temperature, or the load may be used, or a plurality of these may be combined. For example, the water temperature is detected in step S23, and it is determined whether the water temperature detected in step S24 is equal to or higher than the set temperature. When the temperature is higher than the set temperature, the clutch 50 is set to “contact” or the load is detected in step S23. It is determined whether or not the load detected in step S is equal to or lower than the set load. If the load is lower than the set load, the clutch 50 is set to “engaged”, or the engine speed is set to be equal to or higher than the set temperature in step S24 In such a case, the clutch 50 can be “contacted”.

  When the clutch 50 is in the “contact” state, the lift pump 45 is actuated, so that the lift cylinder 52 is driven, and the working machine attached to the lift coupling mechanism 2 may be lifted or lowered unintentionally. In order to prevent this, the following control is performed. After setting the clutch 50 to “contact” (S25), the height of the work implement is detected by the lift position sensor 99. The lift position sensor 99 may be provided in the lift cylinder 52 to detect the stroke thereof, or may detect the rotation angle of the lift arm of the lifting / lowering connection mechanism 2. Further, the operation position of the elevating lever serving as the operation means 95 of the operation unit 4 or the value of the setting dial is read (S27), and the detected value of the lift position sensor 99 is compared with the value of the operation position of the operation means 95. It is determined whether or not (S28). If they match, the state is kept as it is, waiting for operation, and when the operator operates the operation means 95, the elevation control valve 48 is switched to raise and lower the work implement (S30).

If the detected value of the lift position sensor 99 does not match the value of the operation position of the operation means 95, the lift is stopped (S31). In other words, if the detection value of the lift position sensor 99 and the value of the operation position of the operation means 95 do not match, the control means 60 performs control to switch the valve so as to match, so that it moves unexpectedly. In order to prevent this unintentional lifting of the work machine, the lift control valve 48 is not operated when the detected value of the lift position sensor 99 and the value of the operation position of the operation means 95 do not coincide immediately after the clutch “contact”. . However, it is also possible to perform control so that lowering is prohibited and rising is possible. This can also be selected.
Note that the control of the elevation control valve 48 can be similarly controlled in the tilt control valve 49 and the sub control valve 58. In the case of the sub control valve 58, for example, a front loader is attached to the front of the machine body, and means for setting the height of the front loader and means for detecting the height of the front loader are connected to the control means 60. The above-described control is performed when the engine is started.
The above control is similarly controlled during restart.

  As described above, in the configuration in which power is transmitted from the output shaft of the engine 3 to the hydraulic pump via the power transmission means, the engine starting means, the temperature detection means for detecting the temperature related to the engine 3, and the power transmission are connected and disconnected. A clutch 50, a motor 51 serving as an actuator for connecting / disconnecting the clutch 50, and a control means 60 for controlling the motor 51 serving as the actuator are provided. Since the clutch 51 is disengaged by operating the motor 51 serving as an actuator when it is lower, the clutch 50 is disposed on the power transmission path between the output shaft of the engine 3 and the input shaft 45a of the hydraulic pump 45. When the engine 3 is started, the load by the hydraulic pump 45 is disconnected from the power transmission path to reduce the load. It is possible to easily start. Therefore, there is no need to provide an oil passage or switching valve for bypassing the oil discharged from the hydraulic pump 45, and control for reducing the flow rate of the hydraulic oil is not required. it can.

  A gear case is interposed between the output shaft of the engine 3 and a hydraulic pump, and a plurality of hydraulic pumps 40, 41, 42, 43, 44, 45, and 46 are attached to the gear cases 30, 33, and 47. Since the clutch 50 is disposed between the lift pump 45 and the sub gear case 47, which is the hydraulic pump having the largest capacity among the plurality of hydraulic pumps, when starting the engine at a low temperature, the hydraulic pump with a large load is disconnected. Therefore, it can be started easily. Further, since the hydraulic pressure source required at the start is not stopped, a safe and proper start can be performed.

  The actuator is constituted by a motor 51, and an operation cam 73 is attached to an output shaft 85a from the motor 51 via a position adjusting unit 61 so that the actuator can be rotated. The operation cam 73 disengages the clutch 50. Since it is brought into contact with the clutch arm 72 to be operated, the position adjusting unit 61 can absorb any manufacturing error or assembly error between the motor 51 and the operation cam 73. Therefore, it is possible to protect the clutch 50 from being deformed without causing excessive force when it is operated, to reliably operate the clutch 50 "disconnect" or "contact", and to eliminate adjustment work after assembly. Further, as compared with the configuration in which the clutch arm 72 is directly driven by the motor 51, the manufacturing / assembly accuracy can be lowered, and the cost can be reduced. Further, since the clutch arm 72 is rotated by the operation cam 73 to connect / disconnect the clutch 50, the capacity of the motor 51 can be reduced and the existing power motor can be used, thereby reducing the cost.

  A delay mechanism is provided between the clutch 50 and the operation cam 73 so that the clutch 50 is gradually "contacted", so that the impact when the clutch 50 is "contacted" can be reduced, and the lift pump 45 Will not operate suddenly, and the durability of the hydraulic pump can be improved without the sudden rise of the working machine. The timing at which the “contact” of the clutch 50 is gradually performed can be easily realized by changing the profile shape of the operation cam 73 constituting the delay mechanism or the return spring of the clutch 50.

  Further, the control means 60 for controlling the motor 51 is provided with delay means 60a for gradually performing “contact” of the clutch. Therefore, the clutch 50 is gradually “contacted” easily and inexpensively by the program of the control means 60. Therefore, the lift pump 45 does not operate suddenly.

  Further, since the manual operation means 62 is provided in the vicinity of the operation cam 73, the clutch operation portion can be concentratedly arranged so that the position can be easily understood. In other words, the operation cam 73 is separated from the operation cam 73. The engine 51 can be operated by a route different from the drive transmission system of the motor 51, and the engine 3 can be started by manually disengaging the clutch 50 in an emergency such as a failure.

  A rotation speed sensor 91 serving as a rotation speed detection means for detecting the rotation speed of the engine 3 is provided, and the clutch 50 is brought into “contact” at a set rotation speed substantially the same as the idling rotation speed. The clutch 50 is “contacted” at a stable rotational speed 3, the hydraulic pump 45 can be operated without difficulty, and the lift cylinder 52 serving as a hydraulic actuator can be reliably operated.

Since the release setting rotation speed changing means 92 that can change the setting rotation speed of the engine 3 that makes the clutch 50 “contact” is provided, the timing of “contact” is set and operated according to the operator's feeling. Can improve workability and workability.
Since the operation unit 4 is provided with the display means 93 for displaying the state of "disengaged" and "contacted" of the clutch 50, the control at the time of low temperature start is performed or the clutch 50 becomes "disconnected" and the hydraulic pump It is possible to easily recognize whether the motor 51 is stopped, whether the motor 51, the hydraulic pump or the like is in a failure state.

  A plurality of hydraulic pumps that are driven by power from the engine 3 and a clutch 50 that is disposed on the input shaft side of the lift pump 45 that is a working hydraulic pump among the plurality of hydraulic pumps and connects and disconnects the power. A temperature detecting means (a water temperature sensor 90 or an oil temperature sensor) for detecting a temperature related to the engine 3, a motor 51 serving as an actuator for operating the clutch 50, and a control means 60 for controlling the motor 51 serving as the actuator. The control means 60 operates the motor 51 serving as an actuator to “disengage” the clutch when the engine is started when the detected value of the temperature detection means is a low temperature that is equal to or lower than a set temperature. This makes it possible to start the engine easily by reducing the load at the time of starting the engine without driving a hydraulic pump having a large size. And since the load at the time of engine starting is reduced, the engine can be downsized, and the airframe can be downsized and the cost can be reduced.

  The control means 60 is provided with a load detection means 60b. After the engine 3 is started, the control means 60 operates the motor 51 serving as an actuator to operate the clutch 50 when the engine load becomes a set value or less. Is set to “contact”, so that the clutch 50 is set to “contact” in a state where the load of the engine 3 is reduced and the rotation is stable, the load on the engine 3 is suppressed, the durability of the engine 3 can be improved, and the hydraulic pump Can be driven reliably.

  The control means is provided with a rotational speed sensor 91 that serves as an engine rotational speed detection means. After the engine 3 is started, the control means 60 is a motor that acts as an actuator when the engine rotational speed is equal to or higher than a set rotational speed. 51 is operated to make the clutch “contact”, so that the hydraulic pump is operated after the engine 3 is stably rotated, the durability of the engine 3 can be improved, and the hydraulic pump is driven reliably. it can.

  After the engine 3 is started, the control means 60 operates the motor 51 serving as an actuator when the engine load is equal to or lower than a set value and the engine speed is equal to or higher than the set speed, thereby engaging the clutch 50. Therefore, the hydraulic pump is operated after the engine 3 has been stably rotated, the load at the time of starting is further reduced, the durability of the engine 3 can be improved, and the hydraulic pump is driven reliably. it can.

  After the engine 3 is started, the control means 60 operates the motor 51 serving as an actuator to “engage” the clutch 50 when the detected value of the temperature detection means becomes equal to or higher than a set temperature. The hydraulic pump is operated after 3 is warmed and has a stable rotation, so that the durability of the engine 3 can be improved and the hydraulic pump can be driven reliably.

  The control means 60 is connected to a lift valve position detecting means, a lifting operation position detecting means and a control valve for switching oil supply to the hydraulic actuator, and when the clutch 50 is "contacted", the control means includes: The lift position and the lift operation position of the work implement are detected and compared. When the lift position and the operation position do not match, the operation of the lift control valve 48 that controls the hydraulic actuator is stopped, so that the clutch 50 becomes “contact”. At the same time, the lift cylinder 52 does not operate, the work implement does not move up and down unintentionally, and the surrounding equipment or the like is not damaged.

  When the clutch 50 is “contacted”, the control means 60 detects and compares the lift position of the work implement and the lift operation position, and if the lift position and the operation position do not match, the lift lowering operation by the hydraulic actuator is Prohibit and allow ascending operation, and at the same time the clutch 50 is “contacted”, the work machine will not descend, the equipment located under the work machine will not be crushed by mistake, and the clutch At the same time as 50 becomes “contact”, it is raised when the work implement is not in the set position, so that preparation for the start of work can be performed smoothly.

Since the temperature detection means detects the temperature of the cooling water or the temperature of the lubricating oil or hydraulic oil, it is possible to appropriately determine whether the engine 3 can be easily started at a low temperature.
The control means 60 is connected to a low-temperature start control selection means 96 for selecting whether or not to perform low-temperature engine start control, and can arbitrarily select low-temperature engine start control. Can be selected to operate or not required and can be selected according to work.

3 Engine 45 Lift pump 50 Clutch 51 Actuator (motor)
60 Control means 90 Temperature detection means (water temperature sensor)

Claims (9)

  A plurality of hydraulic pumps driven by power from the engine, a clutch disposed on the input shaft side of the working hydraulic pump among the plurality of hydraulic pumps, and a temperature for detecting a temperature related to the engine A detecting means, an actuator for operating the clutch, and a control means for controlling the actuator. The control means, when the detected value of the temperature detecting means is a low temperature below a set temperature, A hydraulic pump control device that is actuated to disengage the clutch.   The control means is provided with a load detection means, and after the engine is started, the control means operates the actuator to make the clutch “contact” when the engine load becomes a set value or less. The hydraulic pump control device according to claim 1.   The control means is provided with an engine speed detecting means, and after the engine is started, the control means operates the actuator to bring the clutch into an “engaged” state when the engine speed becomes equal to or higher than a set speed. The hydraulic pump control device according to claim 1, wherein:   The control means is provided with a load detection means and a rotation speed detection means, and after starting the engine, the control means is an actuator when the engine load is equal to or lower than a set value and the engine speed is equal to or higher than the set rotation speed. The hydraulic pump control device according to claim 1, wherein the clutch is brought into “contact” by actuating the valve.   2. The control unit according to claim 1, wherein after the engine is started, the control unit operates the actuator to bring the clutch into “contact” when a detected value of the temperature detection unit becomes equal to or higher than a set temperature. The hydraulic pump control device described.   The control means is connected to a lift position detecting means, a lifting operation position detecting means of the work implement, and a control valve for switching oil supply to the hydraulic actuator, and when the clutch is "contacted", the control means The lift position and the lift operation position are detected and compared, and if the lift position does not match the operation position, the operation of the control valve that controls the hydraulic actuator is stopped. The hydraulic pump control device according to claim 1.   The control means is connected to a lift position detecting means, a lifting operation position detecting means and a hydraulic actuator control valve of the work implement, and when the clutch is "contacted", the control means 6. The position of the vehicle is detected and compared, and if the lift position and the operation position do not match, the lift lowering operation by the hydraulic actuator is prohibited and the lifting operation is permitted. The hydraulic pump control device described in 1.   The hydraulic pump control device according to claim 5, wherein the temperature detection unit detects a cooling water temperature or a temperature of the lubricating oil.   The low temperature start control selection means for selecting execution or non-execution of low temperature engine start control is connected to the control means, and low temperature engine start control can be arbitrarily selected. Item 8. The hydraulic pump control device according to any one of Items 7.

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