Work machines and operating devices for work machines

Abstract

The purpose of the present invention is to provide a work machine and an operation device for a work machine with improved operability.　A work machine comprising an operation device that can be operated in a first direction and a second direction, a hydraulic pump that supplies hydraulic oil, a hydraulic actuator, a direction switching valve that controls the hydraulic oil flowing from the hydraulic pump to the hydraulic actuator, and a control device that controls the direction switching valve on the basis of the amount of operation on the operation device, wherein the operation device is configured such that because of its structure or arrangement, force is likely to be released in the second direction when the operation device is operated in the first direction, or force is likely to be released in the first direction when the operation device is operated in the second direction, and the direction in which force is likely to be released has a relatively large insensitive region.

Description

Technical Field

[0001] The present disclosure relates to a working machine and an operating device for a working machine.

Background Art

[0002] A working machine including a lower traveling body, an upper revolving body that is rotatable with respect to the lower traveling body, an attachment attached to the upper revolving body, a swing hydraulic motor that swings the upper revolving body, and a hydraulic actuator that drives the attachment is known (Patent Document 1). Further, Patent Document 2 discloses an operating device for a hydraulic working machine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, an operating device for operating a working machine can be operated in, for example, the left-right direction and the front-rear direction. One hydraulic actuator operates in response to an operation amount in the left-right direction, and another hydraulic actuator operates in response to an operation amount in the front-rear direction. Therefore, when operating the operating device in one direction, there is a risk of unintentionally operating the operating device in another direction.

[0005] Therefore, an object of the present invention is to provide a working machine and an operating device for a working machine that improve operability.

Means for Solving the Problems

[0006] A working machine according to an embodiment of the present invention is The operating leverAn operating device that can be operated in a first and second direction, and a hydraulic pump that supplies hydraulic fluid, 1 Hydraulic actuators and The second hydraulic actuator and From the hydraulic pump 1 Controlling the hydraulic fluid flowing through the hydraulic actuator. 1 Directional control valve and A second directional control valve controls the hydraulic fluid flowing from the hydraulic pump to the second hydraulic actuator, and the first direction of the operating lever. Based on the amount of manipulation, 1 Controlling the directional control valve The second directional control valve is controlled based on the amount of operation of the operating lever in the second direction. The control device comprises, and the operating device is The device comprises a first return spring for returning the operating lever tilted in the first direction to a neutral position, and a second return spring for returning the operating lever tilted in the second direction to a neutral position, wherein the spring constant of the second return spring is greater than the spring constant of the first return spring. When operated in the second direction, the force is more easily released in the first direction. The more the amount of manipulation in the second direction increases, the larger the dead zone in the first direction becomes. It is structured in this way. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a work machine and an operating device for a work machine that improve operability. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of an excavator according to an embodiment of the present invention. [Figure 2] Figure 1 is a top view of the shovel. [Figure 3] This figure shows an example of the configuration of a hydraulic system installed in the excavator shown in Figure 1. [Figure 4] This is a diagram showing an example configuration of an electric operating system. [Figure 5] This is a top-down perspective view of the driver's seat inside the cabin. [Figure 6] This is a cross-sectional view of the operating device. [Figure 7] This is a schematic diagram illustrating the strength of the return springs in the left-right and front-back directions in the operating device. [Figure 8] This is a schematic diagram illustrating the movement of the control lever when the operator tilts it backward. [Figure 9] This diagram shows the dead zone for left-right operation in a conventional excavator. [Figure 10] This figure shows the dead zone during left-right operation of the shovel in this embodiment. [Figure 11] It is a diagram showing a dead zone in the front - rear direction operation of the excavator in this embodiment. [Figure 12] It is a schematic diagram explaining the strength of the return springs in the left - right direction and the front - rear direction of the operating device. [Figure 13] It is a schematic diagram explaining the movement of the operation lever when performing the boom - raising operation and the bucket - closing operation simultaneously. [Figure 14] It is a schematic diagram showing an example of the operable range of the operating device in the excavator according to this embodiment and the maximum operation amount at which the spool stroke amount of the direction switching valve becomes maximum. [Figure 15] It is a diagram showing an example of the operation of the operating device. [Figure 16] It is a diagram showing another example of the operation of the operating device. [Figure 17] It is a schematic diagram showing an example of the operable range of the operating device in the excavator according to the modified example and the maximum operation amount at which the spool stroke amount of the direction switching valve becomes maximum.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and the description thereof is omitted.

[0010] First, referring to FIGS. 1 and 2, an excavator (working machine) 100 as an embodiment of the present invention will be described. FIG. 1 is a side view of the excavator 100, and FIG. 2 is a top view of the excavator 100.

[0011] In this embodiment, the lower traveling body 1 of the excavator 100 includes crawlers 1C. The crawlers 1C are driven by a traveling hydraulic motor 2M as a traveling actuator mounted on the lower traveling body 1. Specifically, the crawlers 1C include a left crawler 1CL and a right crawler 1CR. The left crawler 1CL is driven by a left traveling hydraulic motor 2ML, and the right crawler 1CR is driven by a right traveling hydraulic motor 2MR.

[0012] The upper rotating body 3 is mounted on the lower traveling body 1 via a rotating mechanism 2 so as to be able to rotate. The rotating mechanism 2 is driven by a rotating hydraulic motor 2A, which is mounted on the upper rotating body 3 as a rotating actuator.

[0013] A boom 4 is attached to the upper rotating body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6, which serves as an end attachment, is attached to the tip of the arm 5. The boom 4, arm 5, and bucket 6 constitute an excavation attachment AT, which is an example of an attachment. The boom 4 is driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is driven by a bucket cylinder 9. The boom cylinder 7, arm cylinder 8, and bucket cylinder 9 constitute an attachment actuator.

[0014] The boom 4 is supported so as to be able to rotate up and down relative to the upper slewing body 3. A boom angle sensor S1 is attached to the boom 4. The boom angle sensor S1 can detect the boom angle θ1, which is the rotation angle of the boom 4. The boom angle θ1 is, for example, the angle of upward movement from the lowest position of the boom 4. Therefore, the boom angle θ1 is maximum when the boom 4 is raised to its highest position.

[0015] Arm 5 is rotatably supported relative to boom 4. An arm angle sensor S2 is attached to arm 5. The arm angle sensor S2 can detect the arm angle θ2, which is the rotation angle of arm 5. The arm angle θ2 is, for example, the opening angle from the most closed position of arm 5. Therefore, the arm angle θ2 is maximum when arm 5 is fully open.

[0016] The bucket 6 is rotatably supported on the arm 5. A bucket angle sensor S3 is attached to the bucket 6. The bucket angle sensor S3 can detect the bucket angle θ3, which is the rotation angle of the bucket 6. The bucket angle θ3 is, for example, the opening angle from the most closed position of the bucket 6. Therefore, the bucket angle θ3 is maximum when the bucket 6 is fully open.

[0017] In the embodiment shown in Figure 1, the boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3 are each composed of a combination of an acceleration sensor and a gyro sensor. However, they may also be composed of only an acceleration sensor. Furthermore, the boom angle sensor S1 may be a stroke sensor attached to the boom cylinder 7, or it may be a rotary encoder, potentiometer, or inertial measuring device, etc. The same applies to the arm angle sensor S2 and bucket angle sensor S3.

[0018] The upper rotating body 3 is equipped with a cabin 10 that serves as the operator's cab, and is also fitted with a power source such as an engine 11. The upper rotating body 3 is also fitted with a spatial recognition device 70, a direction detection device 71, a positioning device 73, a machine tilt sensor S4, and a rotational velocity sensor S5. Inside the cabin 10 are an operating device 26, a controller 30, an information input device 72, a display device D1, and an audio output device D2. For convenience, in this document, the side of the upper rotating body 3 to which the excavation attachment AT is attached is referred to as the front, and the side to which the counterweight is attached is referred to as the rear.

[0019] The spatial recognition device 70 is configured to recognize objects in the three-dimensional space surrounding the shovel 100. The spatial recognition device 70 is also configured to calculate the distance from the spatial recognition device 70 or the shovel 100 to the recognized object. The spatial recognition device 70 may be, for example, an ultrasonic sensor, millimeter-wave radar, monocular camera, stereo camera, LIDAR, distance image sensor, or infrared sensor. In the example shown in Figures 1 and 2, the spatial recognition device 70 includes a forward sensor 70F mounted on the front upper end of the cabin 10, a rear sensor 70B mounted on the rear upper end of the upper rotating body 3, a left sensor 70L mounted on the left upper end of the upper rotating body 3, and a right sensor 70R mounted on the right upper end of the upper rotating body 3. An upward sensor for recognizing objects in the space above the upper rotating body 3 may be mounted on the shovel 100.

[0020] The orientation detection device 71 is configured to detect information regarding the relative relationship between the orientation of the upper rotating body 3 and the orientation of the lower traveling body 1. The orientation detection device 71 may consist of, for example, a combination of a geomagnetic sensor attached to the lower traveling body 1 and a geomagnetic sensor attached to the upper rotating body 3. Alternatively, the orientation detection device 71 may consist of a combination of a GNSS receiver attached to the lower traveling body 1 and a GNSS receiver attached to the upper rotating body 3. The orientation detection device 71 may also be a rotary encoder or a rotary position sensor. In a configuration in which the upper rotating body 3 is driven to rotate by a rotating motor generator, the orientation detection device 71 may be configured as a resolver. The orientation detection device 71 may be attached to, for example, a center joint provided in relation to a rotation mechanism 2 that realizes relative rotation between the lower traveling body 1 and the upper rotating body 3.

[0021] The orientation detection device 71 may consist of a camera mounted on the upper rotating body 3. In this case, the orientation detection device 71 applies known image processing to the image (input image) captured by the camera mounted on the upper rotating body 3 to detect the image of the lower traveling body 1 included in the input image. Then, the orientation detection device 71 identifies the longitudinal direction of the lower traveling body 1 by detecting the image of the lower traveling body 1 using known image recognition techniques. Then, it derives the angle formed between the longitudinal axis direction of the upper rotating body 3 and the longitudinal direction of the lower traveling body 1. The longitudinal axis direction of the upper rotating body 3 is derived from the camera mounting position. Since the crawler 1C protrudes from the upper rotating body 3, the orientation detection device 71 can determine the longitudinal direction of the lower traveling body 1 by detecting the image of the crawler 1C. In this case, the orientation detection device 71 may be integrated into the controller 30.

[0022] The information input device 72 is configured to allow the excavator operator to input information to the controller 30. In this embodiment, the information input device 72 is a switch panel installed in close proximity to the display unit of the display device D1. However, the information input device 72 may be a touch panel placed on top of the display unit of the display device D1, or an audio input device such as a microphone located inside the cabin 10. Furthermore, the information input device 72 may be a communication device. In this case, the operator can input information to the controller 30 via a communication terminal such as a smartphone.

[0023] The positioning device 73 is configured to measure the current position. In this embodiment, the positioning device 73 is a GNSS receiver that detects the position of the upper rotating body 3 and outputs the detected value to the controller 30. The positioning device 73 may also be a GNSS compass. In this case, the positioning device 73 can detect the position and orientation of the upper rotating body 3.

[0024] The machine body tilt sensor S4 is configured to detect the tilt of the upper rotating body 3 with respect to a predetermined plane. In this embodiment, the machine body tilt sensor S4 is an acceleration sensor that detects the tilt angle of the upper rotating body 3 around the longitudinal axis and the tilt angle around the left-right axis with respect to the horizontal plane. The longitudinal axis and left-right axis of the upper rotating body 3 are, for example, orthogonal to each other and pass through the shovel center point, which is a point on the rotation axis of the shovel 100.

[0025] The rotational angular velocity sensor S5 is configured to detect the rotational angular velocity of the upper rotating body 3. In this embodiment, the rotational angular velocity sensor S5 is a gyro sensor. The rotational angular velocity sensor S5 may also be a resolver or a rotary encoder, etc. The rotational angular velocity sensor S5 may also detect the rotational speed. The rotational speed may be calculated from the rotational angular velocity.

[0026] Hereinafter, at least one of the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine tilt sensor S4, and slewing angular velocity sensor S5 will also be referred to as an attitude detection device. The attitude of the excavation attachment AT is detected, for example, based on the outputs of the boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3.

[0027] Display device D1 is a device that displays information. In this embodiment, display device D1 is a liquid crystal display installed inside the cabin 10. However, display device D1 may also be the display of a communication terminal such as a smartphone.

[0028] The audio output device D2 is a device that outputs sound. The audio output device D2 includes at least one device that outputs sound to an operator inside the cabin 10, and a device that outputs sound to a worker outside the cabin 10. The audio output device D2 may also be a speaker attached to a communication terminal.

[0029] The operating device 26 is a device used by the operator to operate the actuator. The operating device 26 is installed inside the cabin 10 so that it can be used by the operator seated in the driver's seat.

[0030] The controller 30 is a control device for controlling the shovel 100. In this embodiment, the controller 30 is composed of a computer equipped with a CPU, RAM, NVRAM, and ROM. The controller 30 reads programs corresponding to functional elements such as the information acquisition unit 30a and the control unit 30b from ROM and loads them into RAM, causing the CPU to execute the processing corresponding to each functional element. In this way, each functional element is implemented in software. However, at least one of each functional element may be implemented in hardware or firmware. Note that each functional element is distinguished for the sake of explanation, and it remains part of the controller 30; it does not need to be configured to be physically distinguishable.

[0031] Next, with reference to Figure 3, an example of the configuration of the hydraulic system installed in the excavator 100 will be described. Figure 3 is a diagram showing an example of the configuration of the hydraulic system installed in the excavator 100. In Figure 3, the mechanical power transmission system, hydraulic fluid lines, pilot lines, and electrical control system are shown with double lines, solid lines, dashed lines, and dotted lines, respectively.

[0032] The hydraulic system of the Shovel 100 mainly includes an engine 11, a regulator 13, a main pump 14, a pilot pump 15, a control valve unit 17, an operating device 26, a discharge pressure sensor 28, an operating sensor 29, and a controller 30, etc.

[0033] In Figure 3, the hydraulic system is configured to circulate hydraulic fluid from the main pump 14, driven by the engine 11, to the hydraulic fluid tank via the center bypass pipeline 40 or the parallel pipeline 42.

[0034] The engine 11 is the power source for the shovel 100. In this embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined rotational speed. The output shaft of the engine 11 is connected to the input shafts of the main pump 14 and the pilot pump 15, respectively.

[0035] The main pump 14 is configured to supply hydraulic fluid to the control valve unit 17 via a hydraulic fluid line. In this embodiment, the main pump 14 is a swashplate type variable displacement hydraulic pump.

[0036] The regulator 13 is configured to control the discharge rate of the main pump 14. In this embodiment, the regulator 13 controls the discharge rate of the main pump 14 by adjusting the swash plate tilt angle of the main pump 14 in response to a control command from the controller 30.

[0037] The pilot pump 15 is configured to supply hydraulic fluid to hydraulic control equipment (for example, the pilot ports of the directional control valves 171 to 176, described later) via the pilot line 25 (see Figure 4, described later). In this embodiment, the pilot pump 15 is a fixed-displacement hydraulic pump. The pilot pump 15 may be omitted. In this case, the function that the pilot pump 15 performed may be realized by the main pump 14. That is, the main pump 14 may have a function to supply hydraulic fluid to the hydraulic control equipment after reducing the pressure of the hydraulic fluid by throttling or the like, in addition to the function of supplying hydraulic fluid to the control valve unit 17.

[0038] The control valve unit 17 is a hydraulic control device that controls the hydraulic system in the excavator 100. In this embodiment, the control valve unit 17 includes directional control valves 171 to 176. Directional control valve 175 includes directional control valve 175L and directional control valve 175R, and directional control valve 176 includes directional control valve 176L and directional control valve 176R. The control valve unit 17 is configured to selectively supply hydraulic fluid discharged by the main pump 14 to one or more hydraulic actuators through the directional control valves 171 to 176. Directional control valves 171 to 176 control, for example, the flow rate of hydraulic fluid flowing from the main pump 14 to the hydraulic actuators, and the flow rate of hydraulic fluid flowing from the hydraulic actuators to the hydraulic fluid tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel hydraulic motor 2ML, a right travel hydraulic motor 2MR, and a slewing hydraulic motor 2A.

[0039] The operating device 26 is a device used by the operator to operate the actuator. The operating device 26 includes, for example, an operating lever and an operating pedal. The actuator includes at least one of a hydraulic actuator and an electric actuator. In this embodiment, an electric operating system including an electric operating lever can be used. The amount of lever operation of the electric operating lever is input to the controller 30 as an electrical signal. Solenoid valves (hydraulic control valves 31X1, 31X2, which will be described later in Figure 4) are placed between the pilot pump 15 and the pilot port of each control valve. The solenoid valves are configured to operate in response to electrical signals from the controller 30. With this configuration, when manual operation is performed using the electric operating lever, the controller 30 can move each control valve within the control valve unit 17 by controlling the solenoid valves with an electrical signal corresponding to the amount of lever operation to increase or decrease the pilot pressure. Note that each control valve may be composed of an electromagnetic spool valve. In this case, the electromagnetic spool valve operates in response to an electrical signal from the controller 30 corresponding to the amount of lever operation of the electric operating lever.

[0040] The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In this embodiment, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0041] The operation sensor 29 is configured to detect the operation of the operating device 26 by the operator. In this embodiment, the operation sensor 29 detects the operating direction and amount of the operating device 26 corresponding to each actuator and outputs the detected values ​​to the controller 30. For example, the operation sensor 29 is an angle sensor that detects the operating angle of the operating lever. The operation of the operating device 26 may also be detected using sensors other than the angle sensor.

[0042] The main pump 14 includes a left main pump 14L and a right main pump 14R. The left main pump 14L circulates the hydraulic fluid to the hydraulic fluid tank via the left center bypass pipeline 40L or the left parallel pipeline 42L, while the right main pump 14R circulates the hydraulic fluid to the hydraulic fluid tank via the right center bypass pipeline 40R or the right parallel pipeline 42R.

[0043] The left center bypass pipeline 40L is a hydraulic fluid line that passes through directional control valves 171, 173, 175L, and 176L located within the control valve unit 17. The right center bypass pipeline 40R is a hydraulic fluid line that passes through directional control valves 172, 174, 175R, and 176R located within the control valve unit 17.

[0044] The directional control valve 171 is a spool valve that switches the flow of hydraulic fluid in order to supply the hydraulic fluid discharged by the left main pump 14L to the left travel hydraulic motor 2ML, and to discharge the hydraulic fluid discharged by the left travel hydraulic motor 2ML to the hydraulic fluid tank.

[0045] The directional control valve 172 is a spool valve that switches the flow of hydraulic fluid in order to supply the hydraulic fluid discharged by the right main pump 14R to the right travel hydraulic motor 2MR, and to discharge the hydraulic fluid discharged by the right travel hydraulic motor 2MR to the hydraulic fluid tank.

[0046] The directional control valve 173 is a spool valve that switches the flow of hydraulic fluid in order to supply the hydraulic fluid discharged by the left main pump 14L to the swivel hydraulic motor 2A, and to discharge the hydraulic fluid discharged by the swivel hydraulic motor 2A to the hydraulic fluid tank.

[0047] The directional control valve 174 is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the bucket cylinder 9 and switches the flow of hydraulic fluid in order to discharge the hydraulic fluid in the bucket cylinder 9 to the hydraulic fluid tank.

[0048] Directional control valve 175L is a spool valve that switches the flow of hydraulic fluid to supply the hydraulic fluid discharged by the left main pump 14L to the boom cylinder 7. Directional control valve 175R is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the boom cylinder 7 and also switches the flow of hydraulic fluid to discharge the hydraulic fluid inside the boom cylinder 7 to the hydraulic fluid tank.

[0049] The directional control valve 176L is a spool valve that supplies the hydraulic fluid discharged by the left main pump 14L to the arm cylinder 8, and also switches the flow of hydraulic fluid in order to discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank.

[0050] The directional control valve 176R is a spool valve that supplies the hydraulic fluid discharged by the right main pump 14R to the arm cylinder 8 and switches the flow of hydraulic fluid in order to discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank.

[0051] The left parallel pipeline 42L is a hydraulic fluid line running parallel to the left center bypass pipeline 40L. The left parallel pipeline 42L is configured to supply hydraulic fluid to a downstream directional control valve when the flow of hydraulic fluid through the left center bypass pipeline 40L is restricted or blocked by any of the directional control valves 171, 173, and 175L. The right parallel pipeline 42R is a hydraulic fluid line running parallel to the right center bypass pipeline 40R. The right parallel pipeline 42R is configured to supply hydraulic fluid to a downstream directional control valve when the flow of hydraulic fluid through the right center bypass pipeline 40R is restricted or blocked by any of the directional control valves 172, 174, and 175R.

[0052] The regulator 13 includes a left regulator 13L and a right regulator 13R. The left regulator 13L controls the discharge volume of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in accordance with the discharge pressure of the left main pump 14L. Specifically, the left regulator 13L reduces the discharge volume by adjusting the swash plate tilt angle of the left main pump 14L in accordance with an increase in the discharge pressure of the left main pump 14L. The same applies to the right regulator 13R. This is to ensure that the absorption power of the main pump 14 (e.g., absorbed horsepower), which is expressed as the product of the discharge pressure and the discharge volume, does not exceed the output power of the engine 11 (e.g., output horsepower).

[0053] The operating device 26 includes a left operating lever 26L, a right operating lever 26R, and a travel lever 26D. The travel lever 26D includes a left travel lever 26DL and a right travel lever 26DR.

[0054] The left operating lever 26L is used for slewing and operating the arm 5. When the left operating lever 26L is operated in the forward / backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the directional control valve 176. When it is operated in the left / right direction, it uses the hydraulic fluid discharged by the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the directional control valve 173.

[0055] Specifically, when the left operating lever 26L is operated in the arm closing direction, it introduces hydraulic fluid into the right pilot port of the directional control valve 176L and into the left pilot port of the directional control valve 176R. When the left operating lever 26L is operated in the arm opening direction, it introduces hydraulic fluid into the left pilot port of the directional control valve 176L and into the right pilot port of the directional control valve 176R. Furthermore, when the left operating lever 26L is operated in the left rotation direction, it introduces hydraulic fluid into the left pilot port of the directional control valve 173, and when operated in the right rotation direction, it introduces hydraulic fluid into the right pilot port of the directional control valve 173.

[0056] The right operating lever 26R is used to operate the boom 4 and the bucket 6. When the right operating lever 26R is operated in the forward / backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the directional control valve 175. When it is operated in the left / right direction, it uses the hydraulic fluid discharged by the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the directional control valve 174.

[0057] Specifically, when the right operating lever 26R is operated in the boom lowering direction, it introduces hydraulic fluid into the left pilot port of the directional control valve 175R. When the right operating lever 26R is operated in the boom raising direction, it introduces hydraulic fluid into the right pilot port of the directional control valve 175L and into the left pilot port of the directional control valve 175R. Furthermore, when the right operating lever 26R is operated in the bucket closing direction, it introduces hydraulic fluid into the right pilot port of the directional control valve 174, and when it is operated in the bucket opening direction, it introduces hydraulic fluid into the left pilot port of the directional control valve 174.

[0058] The travel lever 26D is used to operate the crawler 1C. Specifically, the left travel lever 26DL is used to operate the left crawler 1CL. The left travel lever 26DL may be configured to be linked with the left travel pedal. When the left travel lever 26DL is operated in the forward / backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the directional control valve 171. The right travel lever 26DR is used to operate the right crawler 1CR. The right travel lever 26DR may be configured to be linked with the right travel pedal. When the right travel lever 26DR is operated in the forward / backward direction, it uses the hydraulic fluid discharged by the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the directional control valve 172.

[0059] The discharge pressure sensor 28 includes discharge pressure sensors 28L and 28R. Discharge pressure sensor 28L detects the discharge pressure of the left main pump 14L and outputs the detected value to the controller 30. The same applies to discharge pressure sensor 28R.

[0060] The operation sensor 29 includes operation sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. Operation sensor 29LA detects the operation performed by the operator on the left operation lever 26L in the forward and backward directions and outputs the detected value to the controller 30. The operation details include, for example, the direction of lever operation and the amount of lever operation (lever operation angle).

[0061] Similarly, the operation sensor 29LB detects the operator's left-right operation of the left operation lever 26L and outputs the detected value to the controller 30. The operation sensor 29RA detects the operator's forward-backward operation of the right operation lever 26R and outputs the detected value to the controller 30. The operation sensor 29RB detects the operator's left-right operation of the right operation lever 26R and outputs the detected value to the controller 30. The operation sensor 29DL detects the operator's forward-backward operation of the left travel lever 26DL and outputs the detected value to the controller 30. The operation sensor 29DR detects the operator's forward-backward operation of the right travel lever 26DR and outputs the detected value to the controller 30.

[0062] The controller 30 receives the output of the operation sensor 29 and, if necessary, outputs a control command to the regulator 13 to change the discharge amount of the main pump 14. The controller 30 also receives the output of the control pressure sensor 19 located upstream of the throttle 18 and, if necessary, outputs a control command to the regulator 13 to change the discharge amount of the main pump 14. The throttle 18 includes a left throttle 18L and a right throttle 18R, and the control pressure sensor 19 includes a left control pressure sensor 19L and a right control pressure sensor 19R.

[0063] In the left center bypass pipeline 40L, a left throttle 18L is located between the downstream directional control valve 176L and the hydraulic fluid tank. Therefore, the flow of hydraulic fluid discharged by the left main pump 14L is restricted by the left throttle 18L. The left throttle 18L then generates a control pressure to control the left regulator 13L. The left control pressure sensor 19L is a sensor for detecting this control pressure and outputs the detected value to the controller 30. The controller 30 controls the discharge amount of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in accordance with this control pressure. The controller 30 decreases the discharge amount of the left main pump 14L as the control pressure increases, and increases the discharge amount of the left main pump 14L as the control pressure decreases. The discharge amount of the right main pump 14R is controlled in the same way.

[0064] Specifically, when the hydraulic system is in a standby state with none of the hydraulic actuators in the excavator 100 being operated, as shown in Figure 3, the hydraulic fluid discharged from the left main pump 14L passes through the left center bypass pipe 40L to the left constrictor 18L. The flow of hydraulic fluid discharged from the left main pump 14L increases the control pressure generated upstream of the left constrictor 18L. As a result, the controller 30 reduces the discharge volume of the left main pump 14L to the minimum allowable discharge volume, suppressing the pressure loss (pumping loss) when the hydraulic fluid discharged from the left main pump 14L passes through the left center bypass pipe 40L. On the other hand, when any of the hydraulic actuators are operated, the hydraulic fluid discharged from the left main pump 14L flows into the hydraulic actuator being operated via the directional control valve corresponding to the hydraulic actuator being operated. The flow of hydraulic fluid discharged from the left main pump 14L reduces or eliminates the amount reaching the left constrictor 18L, lowering the control pressure generated upstream of the left constrictor 18L. As a result, the controller 30 increases the discharge volume of the left main pump 14L, circulating sufficient hydraulic fluid to the hydraulic actuator being operated, and ensuring reliable operation of the hydraulic actuator. The controller 30 also controls the discharge volume of the right main pump 14R in the same manner.

[0065] With the configuration described above, the hydraulic system in Figure 3 can suppress unnecessary energy consumption in the main pump 14 when in standby mode. Unnecessary energy consumption includes pumping losses caused by the hydraulic fluid discharged by the main pump 14 in the center bypass pipeline 40. Furthermore, when operating a hydraulic actuator, the hydraulic system in Figure 3 can reliably supply the necessary and sufficient hydraulic fluid from the main pump 14 to the hydraulic actuator being operated.

[0066] Next, the information acquisition unit 30a and control unit 30b, which are functional elements of the controller 30, will be described. The information acquisition unit 30a is configured to acquire information about the shovel 100. In this embodiment, the information acquisition unit 30a is configured to acquire information about the shovel 100 from at least one of the following: boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine tilt sensor S4, slewing angular velocity sensor S5, cylinder pressure sensor, slewing pressure sensors (slewing pressure sensors 27X1, 27X2, which will be described later in Figure 4), travel pressure sensor, boom cylinder stroke sensor, arm cylinder stroke sensor, bucket cylinder stroke sensor, discharge pressure sensor 28, operation sensor 29, spatial recognition device 70, orientation detection device 71, information input device 72, positioning device 73, and communication device. The cylinder pressure sensor includes, for example, at least one of the following: boom rod pressure sensor, boom bottom pressure sensor, arm rod pressure sensor, arm bottom pressure sensor, bucket rod pressure sensor, and bucket bottom pressure sensor.

[0067] The information acquisition unit 30a acquires, for example, at least one of the following as information about the shovel 100: boom angle, arm angle, bucket angle, machine tilt angle, slewing angular velocity, boom rod pressure, boom bottom pressure, arm rod pressure, arm bottom pressure, bucket rod pressure, bucket bottom pressure, slewing pressure, travel pressure, boom stroke amount, arm stroke amount, bucket stroke amount, discharge pressure of the main pump 14, operation of the operating device 26 (operating direction, operating amount), information about objects in the three-dimensional space around the shovel 100, information about the relative relationship between the orientation of the upper slewing body 3 and the orientation of the lower traveling body 1, information input to the controller 30, and information about the current position.

[0068] Furthermore, the information acquisition unit 30a acquires information regarding the operation of the shovel 100 based on the acquired information regarding the shovel 100. The information regarding the operation of the shovel 100 includes, for example, information regarding the operations performed by the shovel 100. The operations performed by the shovel 100 include, for example, a single rotation operation that rotates the upper rotating body 3, a combined boom-raising rotation operation that rotates the upper rotating body 3 while raising the boom 4, a combined boom-lowering rotation operation that rotates the upper rotating body 3 while lowering the boom 4, a combined arm-opening rotation operation that rotates the upper rotating body 3 while opening the arm 5, a combined arm-closing rotation operation that rotates the upper rotating body 3 while closing the arm 5, a combined bucket-opening rotation operation that rotates the upper rotating body 3 while opening the bucket 6, and a combined bucket-closing rotation operation that rotates the upper rotating body 3 while closing the bucket 6.

[0069] The control unit 30b is configured to control the movement of the shovel 100 based on the information acquired by the information acquisition unit 30a.

[0070] Next, the operating system of the shovel 100 will be explained using Figure 4. Figure 4 is a diagram showing an example of the configuration of an electric operating system. Specifically, the electric operating system in Figure 4 is an example of a slewing operating system. Note that the electric operating system in Figure 4 can also be similarly applied to the boom operating system, arm operating system, bucket operating system, and travel operating system, etc.

[0071] The electric operating system mainly consists of a pilot-operated control valve unit 17 with a directional control valve 173 (see Figure 3), an operating device 26 as an electric operating lever, a hydraulic control valve 31X1 for left turn operation, a hydraulic control valve 31X2 for right turn operation, a pressure sensor 32X1, a pressure sensor 32X2, and a controller 30.

[0072] The directional control valve 173 controls the flow rate of hydraulic fluid from the main pump 14 to the swivel hydraulic motor 2A, which is a hydraulic actuator. Specifically, the directional control valve 173 has pilot ports P1 and P2, and the spool is moved by supplying hydraulic fluid (pilot pressure) to the pilot ports P1 and P2.

[0073] The operating device 26, which functions as an electric operating lever, has an operating sensor 29 that detects the content of the operator's operation of the operating device 26 (direction of operation, amount of operation) and outputs the detected value to the controller 30.

[0074] The hydraulic control valve 31X1 is located on the pilot line 25 connecting the pilot pump 15 and the pilot port P1 of the directional control valve 173, and supplies hydraulic fluid (pilot pressure) to the pilot port P1 of the directional control valve 173. As a result, the hydraulic control valve 31X1 moves the spool of the directional control valve 173 from the neutral position to one end (right side in Figure 4) in the axial direction. The hydraulic fluid supplied from the main pump 14 is supplied to the left port of the swing hydraulic motor 2A, allowing the upper swing body 3 to swing to the left.

[0075] The hydraulic control valve 31X2 is located on the pilot line 25 connecting the pilot pump 15 and the pilot port P2 of the directional control valve 173, and supplies hydraulic fluid (pilot pressure) to the pilot port P2 of the directional control valve 173. As a result, the hydraulic control valve 31X1 moves the spool of the directional control valve 173 from the neutral position to the other end (left side in Figure 4) in the axial direction. The hydraulic fluid supplied from the main pump 14 is supplied to the right port of the swing hydraulic motor 2A, allowing the upper swing body 3 to swing to the right.

[0076] The pressure sensor 32X1 detects the pressure of the hydraulic fluid on the secondary side of the hydraulic control valve 31X1. The pressure sensor 32X1 outputs the detected value to the controller 30.

[0077] The pressure sensor 32X2 detects the pressure of the hydraulic fluid on the secondary side of the hydraulic control valve 31X2. The pressure sensor 32X2 outputs the detected value to the controller 30.

[0078] The slewing pressure sensor 27X1 detects the hydraulic fluid pressure (load pressure during left turn) at the left port of the slewing hydraulic motor 2A, which is a hydraulic actuator. The slewing pressure sensor 27X1 outputs the detected value to the controller 30.

[0079] The slewing pressure sensor 27X2 detects the hydraulic fluid pressure (load pressure during rightward rotation) at the right port of the slewing hydraulic motor 2A, which is a hydraulic actuator. The slewing pressure sensor 27X2 outputs the detected value to the controller 30.

[0080] The discharge pressure sensor 28 detects the discharge pressure of the main pump 14. The discharge pressure sensor 28 outputs the detected value to the controller 30.

[0081] The controller 30 can control the pilot pressure supplied to the pilot port P1 of the directional control valve 173 by controlling the hydraulic control valve 31X1 based on the pressure of the hydraulic fluid on the secondary side of the hydraulic control valve 31X1 detected by the pressure sensor 32X1. Furthermore, the controller 30 can control the pilot pressure supplied to the pilot port P2 of the directional control valve 173 by controlling the hydraulic control valve 31X2 based on the pressure of the hydraulic fluid on the secondary side of the hydraulic control valve 31X2 detected by the pressure sensor 32X2. In other words, the controller 30 is configured to control the spool stroke amount of the directional control valve 173 by controlling the hydraulic control valves 31X1 and 31X2.

[0082] The controller 30 controls the hydraulic control valves 31X1 and 31X2 to control the spool stroke amount of the directional control valve 173 based on the operation details (operation direction, operation amount) of the operating device 26 detected by the operation sensor 29. The controller 30 also controls the hydraulic control valves 31X1 and 31X2 to control the spool stroke amount of the directional control valve 173 based on the operation details (operation direction, operation amount) of the operating device 26 detected by the operation sensor 29 and the discharge pressure of the main pump 14 detected by the discharge pressure sensor 28. The controller 30 also controls the hydraulic control valves 31X1 and 31X2 to control the spool stroke amount of the directional control valve 173 based on the operation details (operation direction, operation amount) of the operating device 26 detected by the operation sensor 29 and the differential pressure between the discharge pressure of the main pump 14 detected by the discharge pressure sensor 28 and the load pressure of the hydraulic actuator.

[0083] Next, an example of the operating device 26 (left operating lever 26L, right operating lever 26R) installed inside the cabin 10 will be explained using Figure 5. Figure 5 is a top perspective view of the driver's seat inside the cabin 10.

[0084] The left control lever 26L is located to the front left of the driver's seat, and the right control lever 26R is located to the front right of the driver's seat.

[0085] When the left control lever 26L is moved forward, the arm 5 opens, and when the left control lever 26L is moved backward, the arm 5 closes. Also, when the left control lever 26L is moved to the left, the upper slewing body 3 rotates counterclockwise to the left when viewed from above, and when the left control lever 26L is moved to the right, the upper slewing body 3 rotates clockwise to the right when viewed from above. Also, when the right control lever 26R is moved forward, the boom 4 descends, and when the right control lever 26R is moved backward, the boom 4 rises. Also, when the right control lever 26R is moved to the left, the bucket 6 closes, and when the right control lever 26R is moved to the right, the bucket 6 opens.

[0086] Next, an example of the operating device 26 (left operating lever 26L, right operating lever 26R) will be explained using Figure 6. Figure 6 is a cross-sectional view of the operating device 26.

[0087] The operating device 26 comprises a rod-shaped operating lever 901, a cam 902, a universal joint 903, a cover 904, a housing 905, a pusher 911 (911A, 911B), a return spring 912 (912A, 912B), and a stroke sensor 913 (913A, 913D).

[0088] The rod-shaped operating lever 901 is attached to the cover 904 and housing 905 via a universal joint 903. This configuration allows the operating lever 901 to be tilted in the forward / backward and left / right directions.

[0089] The cam 902 is fixed below the operating lever 901. The lower surface of the cam 902 contacts the upper end of the pusher 911 which protrudes from the cover 904.

[0090] The cover 904 and housing 905 house the pusher 911, return spring 912, stroke sensor 913, etc. The pusher 911, return spring 912, and stroke sensor 913 are provided in four sets, positioned to the left, right, front, and rear when viewed from above the operating device 26. Figure 6 is a cross-sectional view from the rear towards the front, illustrating the left-facing pusher 911A, return spring 912A, and stroke sensor 913A, and the right-facing pusher 911B, return spring 912B, and stroke sensor 913B. The front-facing pusher 911, return spring 912 (912C, described later in Figure 7, etc.), and stroke sensor 913, as well as the rear-facing pusher 911, return spring 912 (912D, described later in Figure 7, etc.), and stroke sensor 913, have similar configurations, and redundant explanations are omitted.

[0091] The pusher 911 has a cylindrical portion that is placed inside the chamber 906 of the housing 905 and has its upper side closed, and a shaft portion that is placed above the cylindrical portion and protrudes from the hole 907 of the lid 904. The cylindrical portion of the pusher 911 is configured to be movable vertically within the chamber 906 of the housing 905. Furthermore, the shaft portion of the pusher 911 is configured to move vertically as the cylindrical portion of the pusher 911 moves vertically within the chamber 906.

[0092] The return spring 912 returns the tilted operating lever 901 to the neutral position, as will be described later. The return spring 912 is a compression spring located inside the cylindrical part of the pusher 911, with its lower end in contact with the bottom surface of the chamber 906 and its upper end in contact with the top surface of the cylindrical part of the pusher 911. As a result, the return spring 912 biases the pusher 911 upward.

[0093] The stroke sensor 913 detects the vertical movement of the pusher 911. The stroke sensor 913 is an example of an operation sensor 29 (see Figure 3) that detects the operation of the operating device 26 by the operator. The value detected by the stroke sensor 913 is output to the controller 30.

[0094] When the operating lever 901 is not being operated by the operator, the left-right pushers 911A and 911B are biased upward by the return springs 912A and 912B. As a result, the head of pusher 911A pushes the lower left surface of the cam 902, and the head of pusher 911B pushes the lower right surface of the cam 902, thereby returning the operating lever 901 to its neutral position in the left-right direction. Similarly, the front-rear pushers 911 are biased upward by the return springs 912C and 912D. As a result, the head of the front pusher 911 pushes the lower front surface of the cam 902, and the head of the rear pusher 911 pushes the lower rear surface of the cam 902, thereby returning the operating lever 901 to its neutral position in the front-rear direction.

[0095] When the operator operates the operating lever 901, in this case, as shown in Figure 6, if the operator pushes the operating lever 901 to the left, the lower left surface of the cam 902 pushes the pusher 911A. The stroke sensor 913A can detect the amount of leftward movement of the operating lever 901 by detecting the amount of movement of the pusher 911A. The same applies to the rightward, forward, and backward directions.

[0096] Figure 7 is a schematic diagram illustrating the strengths of the left-right and front-back return springs 912A to 912D in the operating device 26. In Figure 7, the operable range 920 of the operating lever 901 is shown. The operating lever 901 is configured to be operable in the left-right and front-back directions within the operable range 920. Also in Figure 7, the strengths of the return springs 912A to 912D are schematically illustrated by the size of the circles.

[0097] Here, the spring constants of the left-right return springs 912A and 912B are set to be smaller than the spring constants of the front-rear return springs 912C and 912D. When an operator operates the control lever 901, the force with which the operator pushes the control lever 901 in the left-right direction is smaller than the force with which the operator pushes the control lever 901 in the front-rear direction. Therefore, as shown in Figure 7, by making the spring constants of the left-right return springs 912A and 912B smaller than the spring constants of the front-rear return springs 912C and 912D, the operator's operability can be improved.

[0098] Furthermore, when an operator operates the operating lever 901, the force with which the operator pushes the operating lever 901 outward (to the left in the case of operating the operating lever 901 operated with the left hand) is smaller than the force with which the operator pushes the operating lever 901 inward (to the right in the case of operating the operating lever 901 operated with the left hand). For this reason, the operator's operability may be improved by making the spring constant of the return spring 912 in the outward direction smaller than the spring constant of the return spring 912 in the inward direction.

[0099] Note that the spring constants of the return springs 912A to 912D are not limited to the relationship shown in Figure 7, and may be equal.

[0100] Figure 8 is a schematic diagram illustrating the movement of the control lever 901 when the operator tilts the control lever 901 backward.

[0101] When the operator moves the operating lever 901 in the direction where the return spring 912 with a large spring constant is located, for example, when the operating lever 901 is moved from the neutral position 901A towards the rear operating position 901B (see white arrow) as shown in Figure 8, the force pushing the operating lever 901 escapes in the direction where the return spring 912 with a small spring constant is located (left and right in the example of Figure 8), causing the operating lever 901 to move in the direction shown by the black arrow. As a result, the operating lever 901 moves to the operating position 901C. This may cause an unintended rotational movement to be input, for example, when performing an arm closing operation.

[0102] Even if the spring constants of the return springs 912A to 912D are equal, the further the operating lever 901 is tilted backward from the neutral position 901A, the greater the pushing force from the rearward return spring 912D becomes. This causes the force pushing the operating lever 901 to escape to the left or right, potentially causing the operating lever 901 to move in the direction indicated by the black arrow. As a result, the operating lever 901 moves to the operating position 901C. This could, for example, cause an unintended rotational movement to be input when performing an arm closing operation.

[0103] Furthermore, when the operator moves the control lever 901 (for example, the left control lever 26L) in the forward and backward directions, there is a tendency to apply force more inward (to the right) than outward (to the left) of the neutral position 901A. As a result, the force pushing the control lever 901 in the forward and backward directions may escape to the right, potentially causing the control lever 901 to move inward (to the right) of the neutral position 901A. This could, for example, unintentionally trigger a rotational movement when performing an arm closing operation.

[0104] Furthermore, when the operator moves the control lever 901 (for example, the left control lever 26L) in the left-right direction, there is a tendency to apply force more inward (rearward) than outward (frontward) of the neutral position 901A. As a result, the force pushing the control lever 901 in the left-right direction escapes to the rearward side, and there is a risk that the control lever 901 will move inward (rearward) of the neutral position 901A. This could, for example, cause an unintended arm closing operation to be input when performing a rotational movement.

[0105] Furthermore, when the operator moves the control lever 901 (for example, the right control lever 26R) in the forward and backward directions, there is a tendency for the force to be applied more inward (to the left) than outward (to the right) of the neutral position 901A. As a result, the force pushing the control lever 901 in the forward and backward directions may escape to the left, potentially causing the control lever 901 to move inward (to the left) of the neutral position 901A. This could, for example, unintentionally trigger a slewing motion when performing a boom raising operation.

[0106] Furthermore, when the operator moves the control lever 901 (for example, the right control lever 26R) in the left-right direction, there is a tendency to apply force more inward (rearward) than outward (frontward) of the neutral position 901A. As a result, the force pushing the control lever 901 in the left-right direction escapes to the rearward side, and there is a risk that the control lever 901 will move inward (rearward) of the neutral position 901A. This could, for example, cause an unintended boom raising operation to be input when performing bucket opening and closing operations.

[0107] Figure 9 shows the insensitive area 921 for left-right operation in a reference example of an excavator.

[0108] A dead zone 921 is provided in which the hydraulic actuator does not operate in response to input from the operating device 26. As shown in Figure 9, in the excavator according to the reference example, the dead zone 921 for left-right operation is constant regardless of the amount of operation in the front-rear direction. For this reason, for example, as shown in Figure 8, when operating the operating lever 901 in the rearward direction to perform the arm closing operation, there is a risk that a slewing operation may be unintentionally input.

[0109] Figure 10 shows the dead zone 922 in the left-right direction of operation in the shovel 100 of this embodiment.

[0110] As shown in Figure 10, in the excavator 100 of this embodiment, the dead zone 922 for left-right operation is set such that the width of the dead zone for left-right operation increases as the amount of operation in the front-back direction increases. Furthermore, as shown in Figure 4, the excavator 100 of this embodiment is an electrically operated system, and the width of the dead zone can be changed by the control of the controller 30.

[0111] In other words, in an operating device 26 that can be operated in the left-right direction (first direction) and the front-back direction (second direction), the dead zone in the left-right direction increases as the amount of operation in the front-back direction increases. For example, as shown in Figure 8, when operating the operating lever 901 in the rearward direction to perform an arm closing operation, even if the force pushing the operating lever 901 escapes to the left or right, resulting in unintended input in the left-right direction, it is possible to prevent unintended rotational movement by increasing the width of the dead zone in the left-right direction, which is the direction in which the force escapes most easily.

[0112] Figure 11 shows the dead zone in the forward and backward movement of the shovel 100 of this embodiment.

[0113] As shown in Figure 11, in the shovel 100 of this embodiment, the insensitive region 923 for forward and backward operation may be set to increase as the amount of operation in the left and right direction increases. Here, the spring constants of the forward and backward return springs 912C and 912D are larger than the spring constants of the left and right return springs 912A and 912B. As a result, when tilting the operating lever 901 in the left and right direction, even if the force pushing the operating lever 901 flows in the forward and backward direction, the forward and backward return springs 912C and 912D, which have larger spring constants, can return it to the neutral position in the forward and backward direction, thus preventing unintended input in the forward and backward direction. However, the insensitive region 923 for forward and backward operation may be set to remain constant regardless of the amount of operation in the left and right direction.

[0114] As described above, according to the shovel 100 of this embodiment, when operating the operating lever 901 in a certain direction, even if the operating lever 901 tilts in another direction where force is easily released, the operation in the other direction can be made insensitive, thereby preventing unintended operation of the shovel 100. This improves the operability of the shovel 100.

[0115] The direction in which force is most easily released is determined, for example, by the strength of the four return springs 912A to 912D, which are positioned in the front, back, left, and right directions of the neutral position 901A. For example, if the spring constants of the return springs 912C and 912D in the front-back direction are greater than the spring constants of the return springs 912A and 912B in the left-right direction, the operating lever 901 will be more likely to unintentionally tilt to the left or right when operated in the front-back direction.

[0116] Furthermore, the direction in which force is most easily released can be determined, for example, by the structure of the human arm. For instance, when an operator pushes the control lever 901 (left control lever 26L) backward, they tend to pull it slightly inward (to the right). Alternatively, when pushing the control lever 901 (right control lever 26R) backward, they tend to pull it slightly inward (to the left). As a result, the control lever 901 may unintentionally tilt to the left or right when pushed backward.

[0117] Although the explanation uses the operating device 26 (left operating lever 26L) operated by the operator with their left hand as an example, the same can be applied to the operating device 26 (right operating lever 26R) operated by the operator with their right hand. Furthermore, the relationship between the operating direction of the operating device 26 shown in Figure 3, etc., and the operation of each hydraulic actuator (slewing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, bucket cylinder 9) is just an example and is not limited to this.

[0118] Furthermore, as shown in Figure 11, in the excavator 100 according to this embodiment, the insensitive area 923 for forward and backward operation was described as being constant regardless of the amount of operation in the left and right directions. However, this is not limited to this, and the insensitive area in the forward and backward directions may increase as the amount of operation in the left and right directions increases.

[0119] Furthermore, in this embodiment of the shovel 100, the example described is when the spring constants of the front-rear return springs 912C and 912D are larger than the spring constants of the left-right return springs 912A and 912B (see Figures 7 and 8), but this is not the only example. The spring constants of the return springs 912A to 912D may be equal.

[0120] In a configuration where the spring constants of the return springs 912A to 912D are equal, as shown in Figure 10, the dead zone in the left-right direction may increase as the amount of operation in the front-rear direction increases. This allows, for example, when operating the operating lever 901 in the rearward direction to perform the arm closing operation, the more the operating lever 901 is tilted backward, the greater the force pushing back by the rearward return spring 912D becomes. As a result, even if the force pushing the operating lever 901 escapes to the left or right, causing unintended left-right input, increasing the width of the dead zone in the left-right direction, which is the direction in which the force escapes most easily, can prevent unintended rotational movement.

[0121] Furthermore, in a configuration where the spring constants of the return springs 912A to 912D are equal, the dead zone in the front-to-back direction may be increased as the amount of operation in the left-to-right direction increases. This allows, for example, when operating the operating lever 901 to the left to perform a leftward rotation, the more the operating lever 901 is tilted to the left, the greater the force pushing back by the return spring 912A on the left side becomes. As a result, even if the force pushing the operating lever 901 escapes vertically and an unintended vertical input occurs, increasing the width of the dead zone in the vertical direction, which is the direction in which the force escapes most easily, can prevent unintended arm opening and closing movements.

[0122] It should be noted that the operating device 26 has been described as having a direction in which force is easily released due to its structure (spring constant of the return spring), but this is not the only case. The description can also be applied when the arrangement of the operating device 26 has a direction in which force is easily released. That is, the operating device 26, which can be operated in a first direction and a second direction, may be configured such that, structurally or in terms of its arrangement, force is easily released in the second direction when operated in the first direction, or vice versa, and the insensitive region is relatively large in the direction in which force is easily released.

[0123] Incidentally, the operating device is equipped with return springs that return the operating lever to the neutral position in the left-right and front-back directions. Therefore, when the operating lever is moved diagonally, for example, when the operating lever is moved diagonally to the right and forward, it is necessary to press both the front return spring and the right return spring, which requires a large operating force to operate the operating lever and also increases the amount of movement from the neutral position of the operating lever.

[0124] Figure 12 is a schematic diagram illustrating the strengths of the left-right and front-back return springs 912A to 912D in the operating device 26. Figure 12 shows the operating range 920 of the operating lever 901. The operating lever 901 is configured to be operable in the left-right and front-back directions within the operating range 920. Figure 12 also schematically illustrates the strengths of the return springs 912A to 912D using the size of the circles.

[0125] Here, the spring constants of the left-right return springs 912A and 912B are set to be smaller than the spring constants of the front-rear return springs 912C and 912D. When an operator operates the control lever 901, the force with which the operator pushes the control lever 901 in the left-right direction is smaller than the force with which the operator pushes the control lever 901 in the front-rear direction. Therefore, as shown in Figure 12, by making the spring constants of the left-right return springs 912A and 912B smaller than the spring constants of the front-rear return springs 912C and 912D, the operator's operability can be improved.

[0126] Furthermore, when an operator operates the operating lever 901, the force with which the operator pushes the operating lever 901 outward (to the left in the case of operating the operating lever 901 operated with the left hand) is smaller than the force with which the operator pushes the operating lever 901 inward (to the right in the case of operating the operating lever 901 operated with the left hand). For this reason, the operator's operability may be improved by making the spring constant of the return spring 912 in the outward direction smaller than the spring constant of the return spring 912 in the inward direction.

[0127] Note that the spring constants of the return springs 912A to 912D are not limited to the relationship shown in Figure 12, and may be equal.

[0128] Figure 13 is a schematic diagram illustrating the movement of the operating lever 901 when the boom raising operation and bucket closing operation are performed simultaneously.

[0129] Here, we will describe the excavator in the reference example. In the excavator in the reference example, the controller 30 controls the spool stroke amount of the directional control valve 174 corresponding to the bucket cylinder 9 based on the amount of left-right movement of the operating lever 901. Therefore, to maximize the spool stroke amount of the directional control valve 174, the operating lever 901 is operated to the maximum left-right position within the operable range 920. In addition, the controller 30 controls the spool stroke amount of the directional control valve 175 corresponding to the boom cylinder 7 based on the amount of front-back movement of the operating lever 901. Therefore, to maximize the spool stroke amount of the directional control valve 175, the operating lever 901 is operated to the maximum front-back position within the operable range 920.

[0130] For example, when performing boom raising and bucket closing operations simultaneously, the operator moves the operating lever 901 to the rear left, from the neutral position 901A to the operating position 901H. In this case, the cam 902 (see Figure 6) fixed to the operating lever 901 pushes in the return springs 912A and 912D. Therefore, when the operating lever 901 is moved diagonally, it is necessary to push in both return springs, requiring a large operating force to operate the operating lever 901, and the amount of movement from the neutral position 901A to the operating position 901H is also large. The same applies when the operating lever 901 is moved to the rear right, front left, or front right. Thus, the operable range 920 of the operating lever 901 includes a difficult-to-operate region 925 where the operating force and the amount of movement are large.

[0131] In the example excavator, the operation is performed using a difficult operating region 925, which requires a large operating force and a large operating range. Operating in such a difficult operating region 925 causes fatigue to the operator.

[0132] FIG. 14 is a schematic diagram showing an example of the operable range 920 of the operating device 26 in the excavator 100 according to the present embodiment and the maximum operation amount 926 at which the spool stroke amount of the direction switching valve becomes maximum.

[0133] As shown in FIG. 14, the controller 30 has different maximum operation amounts 926 in the left - right direction at which the spool stroke amount (control amount) of the direction switching valve 174 corresponding to the bucket cylinder 9 becomes maximum, according to the operation amount of the front - rear direction operation lever 901. In other words, according to the operation amount in the front - rear direction (first direction), the relationship between the operation amount of the operation lever 901 in the left - right direction (second direction) and the maximum operation amount 926 at which the spool stroke amount (control amount) becomes maximum changes. That is, the operation amount of the operation lever 901 in the left - right direction does not match the stroke amount (control amount), and the relationship between the operation amount in the left - right direction (second direction) and the control amount changes depending on the operation amount in the front - rear direction (first direction).

[0134] For example, when the operation lever 901 is operated backward by an operation amount B1, the maximum operation amount 926 in the left direction is the operation amount L1. That is, when the operation lever 901 is operated to the left by the operation amount L1, the controller 30 controls so that the spool stroke amount of the direction switching valve 174 corresponding to the bucket cylinder 9 becomes maximum.

[0135] Also, when the operation lever 901 is operated backward by an operation amount B2 (B2 > B1), the maximum operation amount 926 in the left direction is the operation amount L2 (L2 < L1). That is, when the operation lever 901 is operated to the left by the operation amount L2, the controller 30 controls so that the spool stroke amount of the direction switching valve 174 corresponding to the bucket cylinder 9 becomes maximum. When the operation lever 901 is further tilted to the left, the spool stroke amount of the direction switching valve 174 maintains the maximum.

[0136] Also, when the operation lever 901 is operated in the rearward direction with an operation amount B3 (B3 > B2), the maximum operation amount 926 in the leftward direction becomes the operation amount L3 (L3 < L2). That is, when the operation lever 901 is operated to the leftward direction up to the operation amount L3, the controller 30 controls so that the spool stroke amount of the direction switching valve 174 corresponding to the bucket cylinder 9 becomes maximum. When the operation lever 901 is further tilted to the leftward direction, the spool stroke amount of the direction switching valve 174 maintains the maximum value.

[0137] That is, the controller 30 changes the value (for example, L1 to L3) of the maximum operation amount 926 in the left-right direction at which the spool stroke amount of the direction switching valve 174 corresponding to the bucket cylinder 9 becomes maximum according to the operation amount (for example, B1 to B3) of the operation lever 901 in the front-rear direction. Then, the controller 30 controls the spool stroke amount of the direction switching valve 174 based on the maximum operation amount 926 and the operation amount of the operation lever 901 in the left-right direction. For example, the controller 30 controls the spool stroke amount of the direction switching valve 174 based on the ratio of the maximum operation amount 926 and the operation amount of the operation lever 901 in the left-right direction.

[0138] Similarly, the controller 30 varies the maximum operation amount 926 in the front-rear direction at which the spool stroke amount (control amount) of the direction switching valve 175 corresponding to the boom cylinder 7 becomes maximum according to the operation amount of the operation lever 901 in the left-right direction. In other words, according to the operation amount in the left-right direction, the relationship between the operation amount of the operation lever 901 in the front-rear direction and the maximum operation amount 926 at which the spool stroke amount (control amount) becomes maximum changes. That is, the operation amount of the operation lever 901 in the front-rear direction and the stroke amount (control amount) do not match, and the relationship between the operation amount and the control amount in the front-rear direction changes depending on the operation amount in the left-right direction.

[0139] For example, when the operation lever 901 is operated in the rightward direction with an operation amount R1, the maximum operation amount 926 in the forward direction becomes the operation amount F1. That is, when the operation lever 901 is operated in the forward direction up to the operation amount F1, the controller 30 controls so that the spool stroke amount of the direction switching valve 175 corresponding to the boom cylinder 7 becomes maximum.

[0140] Also, when the operation lever 901 is operated in the right direction with an operation amount R2 (R2 > R1), the maximum operation amount 926 in the forward direction becomes an operation amount F2 (F2 < F1). That is, when the operation lever 901 is operated in the forward direction up to the operation amount F2, the controller 30 controls so that the spool stroke amount of the direction switching valve 175 corresponding to the boom cylinder 7 becomes maximum. When the operation lever 901 is further tilted forward, the spool stroke amount of the direction switching valve 175 maintains the maximum value.

[0141] Also, when the operation lever 901 is operated in the right direction with an operation amount R3 (R3 > R2), the maximum operation amount 926 in the forward direction becomes an operation amount F3 (F3 < F2). That is, when the operation lever 901 is operated in the forward direction up to the operation amount F3, the controller 30 controls so that the spool stroke amount of the direction switching valve 175 corresponding to the boom cylinder 7 becomes maximum. When the operation lever 901 is further tilted forward, the spool stroke amount of the direction switching valve 175 maintains the maximum value.

[0142] That is, the controller 30 changes the value (for example, F1 to F3) of the maximum operation amount 926 in the front - rear direction at which the spool stroke amount of the direction switching valve 175 corresponding to the boom cylinder 7 becomes maximum according to the operation amount (for example, R1 to R3) of the operation lever 901 in the left - right direction. Then, the controller 30 controls the spool stroke amount of the direction switching valve 175 based on the maximum operation amount 926 and the operation amount of the operation lever 901 in the front - rear direction. For example, the controller 30 controls the spool stroke amount of the direction switching valve 175 based on the ratio of the maximum operation amount 926 and the operation amount of the operation lever 901 in the front - rear direction.

[0143] Figure 15 shows an example of operation of the control device 26. The operator moves the control lever 901 backward from the neutral position 901A to the operating position 901D. This causes the controller 30 to maximize the spool stroke of the directional control valve 175 corresponding to the boom cylinder 7. In this state, the operator moves the control lever 901 to the left to the operating position 901E. This causes the controller 30 to maximize the spool stroke of the directional control valve 174 corresponding to the bucket cylinder 9.

[0144] Figure 16 shows another example of operation of the control device 26. The operator moves the control lever 901 from the neutral position 901A to the left, up to the operating position 901F. This causes the controller 30 to maximize the spool stroke of the directional control valve 174 corresponding to the bucket cylinder 9. In this state, the operator moves the control lever 901 backward, up to the operating position 901G, thereby maximizing the spool stroke of the directional control valve 175 corresponding to the boom cylinder 7.

[0145] According to the excavator 100 of this embodiment, hydraulic actuators such as the boom cylinder 7 and bucket cylinder 9 can be operated without using the difficult-to-operate region 925 (see Figure 13), which requires a large operating force and a large operating range. This reduces operator fatigue and improves operability.

[0146] The maximum operating amount 926 was explained using the example of it being set within the operable range 920, but it is not limited to this. Figure 17 is a schematic diagram showing the operable range 920 of the operating device 26 in the modified shovel 100 and an example of the maximum operating amount 926A at which the spool stroke amount of the directional control valve is maximized. As shown in Figure 17, the maximum operating amount 926A may be set outside the operable range 920. In the example shown in Figure 17, even if the operating lever 901 is operated to the maximum of the operable range 920, the spool stroke amount of the directional control valve will not be maximized.

[0147] In complex operations where multiple hydraulic actuators are operated simultaneously, a control method is known that prioritizes the flow rate of hydraulic fluid to a specific hydraulic actuator. In contrast, with the control method shown in Figure 17, even when the operating lever 901 is operated to the maximum of its operable range 920, the spool stroke amount of the directional control valve does not reach its maximum, and hydraulic fluid can be supplied to each of the multiple hydraulic actuators. This allows for complex operations of the shovel 100 in accordance with the operator's actions, thereby improving operability.

[0148] In other words, in the modified excavator 100, the controller 30 changes the value of the maximum left-right operating amount 926A that maximizes the spool stroke amount of the directional control valve 174 corresponding to the bucket cylinder 9, according to the amount of operation of the front-rear operating lever 901. The controller 30 then controls the spool stroke amount of the directional control valve 174 based on the maximum operating amount 926 and the left-right operating amount of the operating lever 901. The controller 30 also changes the value of the maximum front-rear operating amount 926A that maximizes the spool stroke amount of the directional control valve 175 corresponding to the boom cylinder 7, according to the amount of operation of the left-rear operating lever 901. The controller 30 then controls the spool stroke amount of the directional control valve 175 based on the maximum operating amount 926 and the front-rear operating amount of the operating lever 901. For example, the controller 30 controls the spool stroke amount of the directional control valve 175 based on the ratio of the maximum operating amount 926 and the front-rear operating amount of the operating lever 901.

[0149] This allows for minute control of the spool stroke amount of the directional control valve in response to the operation of the operating lever 901.

[0150] Furthermore, the maximum operating range 926 may be partially set within the operating range 920 and partially set outside the operating range 920.

[0151] Although the operating device 26 has been described as being located inside the cabin 10 of the shovel 100, it is not limited to this. It may also be applied to an operating device for a work machine located inside the cabin of the work machine. Furthermore, it may be applied to an operating device for a work machine that is remotely controlled from an external location.

[0152] This application claims priority based on Japanese Patent Application No. 2021-062319, filed on 31 March 2021, and the entire contents of that Japanese Patent Application are incorporated herein by reference.

[0153] Furthermore, this application claims priority based on Japanese Patent Application No. 2021-062449, filed on March 31, 2021, and the entire contents of this Japanese Patent Application are incorporated herein by reference. [Explanation of Symbols]

[0154] 2A Swivel Hydraulic Motor (Hydraulic Actuator) 14. Main pump (hydraulic pump) 26 Operating device 30 Controller (control device) 100 Shovel 171-176 Directional control valve 901 Operating lever 902 Cam 903 Universal Joint 904 Lid 905 enclosure 911 Pusher 912 Return spring 913 Stroke Sensor 920 Operating range 921~923 Blind area 925 Difficult to operate area 926 Maximum operation amount

Claims

1. An operating device that allows the operating lever to be operated in a first direction and a second direction, A hydraulic pump that supplies hydraulic fluid, First hydraulic actuator and The second hydraulic actuator and A first directional control valve controls the hydraulic fluid flowing from the hydraulic pump to the first hydraulic actuator, A second directional control valve controls the hydraulic fluid flowing from the hydraulic pump to the second hydraulic actuator, The control device includes a control device that controls the first directional control valve based on the amount of operation of the operating lever in the first direction, and controls the second directional control valve based on the amount of operation of the operating lever in the second direction, The aforementioned operating device is A first return spring that returns the operating lever tilted in the first direction to the neutral position, The device comprises a second return spring that returns the operating lever, which is tilted in the second direction, to a neutral position, The spring constant of the second return spring is greater than that of the first return spring, so that when operated in the second direction, the force is more easily released in the first direction. The configuration is such that the dead zone in the first direction increases as the amount of operation in the second direction increases. A type of machinery used for industrial work.

2. The first direction is the left-right direction, The second direction is the front-to-back direction. The work machine according to claim 1.

3. As the amount of manipulation in the first direction increases, the dead region in the second direction increases. A working machine according to claim 1 or claim 2.

4. The control device is Depending on the amount of operation in the first direction, the amount of operation in the second direction at which the control amount of the second directional control valve is maximized is different. The work machine according to claim 1.

5. The control device is The control amount of the second directional control valve is controlled based on the operating amount in the second direction that maximizes the control amount of the second directional control valve, and the operating amount in the second direction. The work machine according to claim 4.

6. The larger the amount of operation in the first direction, the smaller the amount of operation in the second direction at which the control amount of the second directional control valve is maximized. The working machine according to claim 4 or claim 5.

7. The aforementioned operating device has an operable range, The control device is Within the aforementioned operable range, the control amount of the first directional control valve and / or the second directional control valve becomes maximum. The work machine according to any one of claims 4 to 6.

8. An operating device for a work machine, wherein the operating lever is operable in a first direction and a second direction, and which can control a first directional control valve that controls the flow of hydraulic fluid from a hydraulic pump to a first hydraulic actuator based on the amount of operation of the operating lever in the first direction, and which can control a second directional control valve that controls the flow of hydraulic fluid from a hydraulic pump to a second hydraulic actuator based on the amount of operation of the operating lever in the second direction, The aforementioned operating device is A first return spring that returns the operating lever tilted in the first direction to the neutral position, The device comprises a second return spring that returns the operating lever, which is tilted in the second direction, to a neutral position, The spring constant of the second return spring is greater than that of the first return spring, so that when operated in the second direction, the force is more easily released in the first direction. The configuration is such that the dead zone in the first direction increases as the amount of operation in the second direction increases. An operating device for industrial machinery.

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