JP2005313819A - Parking brake operation device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parking brake operation device capable of automatically operating a parking brake device without operating a parking brake operation switch when a working vehicle is temporarily stopped in the state of operation of an engine. <P>SOLUTION: The parking brake operation device for a wheel loader is provided with the parking brake device 10 and a brake operation circuit for operating this; and the parking brake operation switch 9. A controller 18 capable of determining whether or not a driver is not seated on a driver's seat and the wheel loader is in the state that traveling is stopped based on a seating detection sensor 15, a vehicle speed detection sensor 16, an advancement/retreating switching switch 17 and the detection values of these is provided. When it is determined that it is in such a state, the parking brake device 10 is operated through the brake operation circuit by the controller 18 even when the engine of the wheel loader is in the operation state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a parking brake actuator for a work vehicle that can apply a braking force to a work vehicle when the vehicle is stopped by operating a parking brake device by operating a parking brake operation switch by a driver, and is particularly useful for a wheel loader. Is.

  For work vehicles that work with work tools such as wheel loaders and forklifts, the braking force is applied to the work vehicle when the vehicle is stopped by the driver's switch operation so that the vehicle body does not move freely when the vehicle is stopped on a slope. A parking brake actuating device is installed so that This parking brake operating device for a work vehicle is usually a parking brake device as a negative brake for applying a braking force to the working vehicle when the vehicle is stopped, a brake operating circuit for operating the parking brake device, and a driver. A parking brake operation switch which is operated to open and close by the operation of the parking brake device and allows the operation of the parking brake device to be released through the brake operation circuit. The parking brake actuating device operates the parking brake device when the driver operates the parking brake actuating switch when the vehicle stops or when the engine of the working vehicle is stopped to stop the supply of hydraulic pressure. A braking force can be applied to the.

  The invention of this application intends to improve such a parking brake operating device in consideration of convenience of work on a work vehicle. In the section of “Best Mode for Carrying Out the Invention” to be described later, an example in which the improvement is applied to a parking brake operating device of a wheel loader that has been conventionally performed by the applicant is shown. In order to facilitate understanding, a wheel loader conventionally used by the applicant and a parking brake operating device installed thereon will be outlined with reference to FIGS.

  3 is a side view showing an overall image of a wheel loader that has been conventionally implemented by the applicant, FIG. 4 is a plan view of the wheel loader of FIG. 3, and FIG. 5 is a state near the driver's seat of the wheel loader of FIG. FIG. 6 is a circuit diagram relating to a parking brake operating device for a wheel loader that has been conventionally implemented by the applicant.

  First, an overview of the wheel loader and basic technical matters will be outlined with reference to FIGS.

  In these drawings, 21 is a vehicle body in a wheel loader as a work vehicle that runs on wheels, 21a is a front vehicle body that forms a front portion of the vehicle body 21 by installing a work machine 25, and 21b is a cab 26. A rear wheel body that forms the rear of the vehicle body 21, 22a is a front wheel that supports the front vehicle body 21a, 22b is a rear wheel that supports the rear vehicle body 21b, and 23 is a front vehicle body 21a and a rear vehicle body 21b. Are connected to each other in a rotatable manner, and 24 is a vehicle body bend for bending the vehicle body 21 by driving the front vehicle body 21a to rotate horizontally with respect to the rear vehicle body 21b. Hydraulic cylinder.

  As shown in FIG. 3, the front vehicle body 21a is pivotally connected to the rear vehicle body 21b at a location of the vehicle body connecting portion 23 so that the front vehicle body 21a can be rotated in the horizontal direction with respect to the rear vehicle body 21b. ing. On the other hand, an end of a vehicle body bending hydraulic cylinder 24 is pivotally connected to the front vehicle body 21a and the rear vehicle body 21b. Therefore, by expanding and contracting the vehicle body bending hydraulic cylinder 24, the front vehicle body 21a is rotated with respect to the rear vehicle body 21b, the vehicle body 21 is bent, the wheel loader is bent, and various operations are performed. can do. Although not shown in the drawing, a traveling hydraulic motor for rotationally driving the front wheels 22a and the rear wheels 22b is installed in the rear vehicle body 21b.

  Reference numeral 25 denotes a work machine (front) configured to provide a lift arm 25a, a bucket 25b, a lift arm cylinder 25c, and a bucket cylinder 25d. A lift arm 25b is attached to the front body body 21a so as to be swingable in the vertical direction, 25b is a bucket attached to the front end portion of the lift arm 25a so as to be able to rotate in the vertical direction, and 25c is extended and retracted to extend the lift arm 25a. A lift arm cylinder that is hydraulically driven so as to swing up and down, 25 d is a bucket cylinder that is hydraulically driven to rotate the bucket 25 b by extending and contracting, and 26 is a vehicle body 21 and a work machine 25 that are driven by the driver. The cab where the maneuver is performed, 27 is the building cover that forms the engine room, etc. 8 is a counterweight to balance the external force acting on the vehicle body 21 at the time of work by the working machine 25.

  As shown in FIG. 4, a pair of lift arms 25a and lift arm cylinders 25c are provided on the left and right sides of the front vehicle body 21a, and one bucket cylinder 25d is provided between the pair of lift arms 25a. The bucket cylinder 25d is connected to the bucket 25b via a link mechanism. By transmitting the expansion and contraction of the bucket cylinder 25d to the link mechanism, the bucket 25b is rotated about a horizontal axis in the vehicle body width direction. Be able to. In the work machine 25, the driver drives the lift arm cylinder 25c and the bucket cylinder 25d, and further drives the vehicle body bending hydraulic cylinder 24 and the traveling hydraulic motor as necessary, so that loose objects such as earth and sand and snow are driven. The excavation work and the snow removal work are performed by scooping up and taking in the bucket 25b. Further, these actuators are appropriately driven to carry the bulk material taken in by the bucket 25b to a transport vehicle such as a dump truck and load it on the loading platform, or to load the bulk material loaded on the transport vehicle in the bucket 25b. Also work.

  As shown in FIG. 5, a driver's seat 30 is installed in the driver's cab 26, and a handle 31 is disposed at the front center of the driver's seat 30. 32 is arranged. An accelerator pedal (traveling pedal) 33 is disposed on the right side of the right brake pedal 32, and a forward / reverse switching lever 34 for switching a forward / reverse switching switch 17 described later is disposed below the handle 31. Has been. Further, a parking brake operation switch 9 (described later) operated by a key is disposed in the vicinity of the right windshield of the handle 31.

  Next, a parking brake operating device for a conventional wheel loader will be described with reference to FIG.

  The parking brake operating device includes a parking brake device 10, a brake operating circuit for operating the parking brake device 10, and a parking brake operating switch 9. When the driver operates the parking brake operating switch 9, The parking brake device 10 is operated through a brake operation circuit so that a braking force can be applied to the wheel loader when the vehicle is stopped. For convenience of explanation, first, the brake operation circuit and the parking brake operation switch 9 will be described sequentially.

  In FIG. 6, 1 is a hydraulic oil tank, 2 is a hydraulic pump that is driven to rotate by an engine (not shown) to generate pressure oil, and 3 is a pressure pump for supplying hydraulic oil to the rod side of the parking brake cylinder 14. The electromagnetic direction switching valve for switching the flow of the pressure oil so as to discharge the pressurized oil to the hydraulic oil tank 1, 4 a is a first for filtering the hydraulic oil supplied from the hydraulic oil tank 1 to the hydraulic pump 2. 4b is a second filter for filtering the pressure oil on the discharge side of the hydraulic pump 2, 5 is a check valve provided in the bypass line of the second filter 4b, 6 is a relief valve, and 7 is A power source for exciting the solenoid of the electromagnetic direction switching valve 3, 8 is a fuse, and 9 is a parking brake operation switch.

  The hydraulic pump 2 also serves as a source of hydraulic pressure for driving the above-described vehicle body bending hydraulic cylinder 24. In the engine for driving the hydraulic pump 2, a traveling hydraulic pump (not shown) for supplying pressure oil to a traveling hydraulic motor is usually driven together with the hydraulic pump 2. Therefore, if the engine is stopped and the driving of the traveling hydraulic pump is stopped in order to park the wheel loader, the driving of the hydraulic pump 2 is also stopped accordingly. The electromagnetic direction switching valve 3 is switched to the left position shown in FIG. 6 when the solenoid is not energized, and blocks the flow of pressure oil from the hydraulic pump 2 to the rod side of the parking brake cylinder 14. At the same time, the pressure oil supplied to the rod side of the parking brake cylinder 14 is discharged to the hydraulic oil tank 1. Further, when the hydraulic pump 2 is driven to rotate by the engine, when the solenoid is energized, it is switched to the right position to supply the hydraulic oil of the hydraulic pump 2 to the rod side of the parking brake cylinder 14.

  The check valve 5 is opened when the second filter 4b is clogged and the pressure in the pipe upstream of the filter 4b rises, and the pressure oil in the pipe is supplied to the second through the bypass pipe. The upstream side of the filter 4b is protected when the second filter 4b is clogged. The brake operating circuit refers to a circuit for operating the parking brake device 10, and in the example shown in FIG. 6, the hydraulic oil tank 1, the hydraulic pump 2, the directional switching valve 3, a pipe line connecting these devices, and the like. It is provided and configured. The parking brake operation switch 9 can demagnetize the solenoid of the direction switching valve 3 when the driver opens (turns it off), and can operate the parking brake device 10 through the brake operation circuit. Further, when the driver closes (turns on) the solenoid of the direction switching valve 3 is excited, the operation of the parking brake device 10 can be released through the brake operation circuit.

  The parking brake device 10 will be described. Reference numeral 11 denotes a parking brake drum that generates a braking force when the brake pad 12 is pressed. The brake pad 12a is a spring for urging the brake pad 12 away from the parking brake drum 11, and 13a is attached to the parking brake cylinder 14 side for transmitting the telescopic motion of the parking brake cylinder 14 to the brake pad 12. The first link 13b is a second link attached to the parking brake drum 11 for transmitting the telescopic motion of the parking brake cylinder 14 to the brake pad 12 in cooperation with the link 13a. The expansion to the parking brake cylinder to release the actuation and operation of the brake pads 12, 14a is a spring for actuating the brake pad 12 during extension and biased to extend the parking brake cylinder 14.

  In the example shown in FIG. 6, the parking brake device 10 includes a parking brake drum 11, a brake pad 12, links 13 a and 13 b, and a parking brake cylinder 14. The parking brake drum 11 is installed on the rotation transmission mechanism side of the traveling hydraulic motor, and the brake pad 12 is installed on the vehicle body 21 side.

  When the directional control valve 3 is switched to the left position shown in FIG. 6 and the pressure oil on the rod side is discharged to the hydraulic oil tank 1, the parking brake cylinder 14 is extended by the bias of the spring 14 a and the brake pad 12. Is activated. That is, the extension movement of the parking brake cylinder 14 is transmitted to the brake pad 12 via the first link 13a and the second link 13b, and the brake pad 12 is pressed against the parking brake drum 11 against the force of the spring 12a. To generate braking force. Further, when the direction switching valve 3 is switched to the right position and the pressure oil of the hydraulic pump 2 is supplied to the rod side of the parking brake cylinder 14, the pressure oil resists the force of the spring 14a and causes the parking brake cylinder 14 to move. Reduce. If it does so, the brake pad 12 will be urged | biased by the spring 12a, will be released | separated from the parking brake drum 11, and will cancel | release operation | movement.

Since the parking brake operating device of the conventional wheel loader is configured as described above, when the driver opens the parking brake operating switch 9 (in conjunction with key operation) and turns it on when getting off, the direction The solenoid of the switching valve 3 is demagnetized to switch the direction switching valve 3 to the left position shown in FIG. Then, the pressure oil supplied to the rod side of the parking brake cylinder 14 can be discharged to the hydraulic oil tank 1 through the brake operation circuit to operate the parking brake device 10. Further, when the engine is stopped, the driving of the hydraulic pump 2 is also stopped and the pressure oil is not supplied to the rod side of the parking brake cylinder 14, so that the parking brake device 10 is operated. A work vehicle equipped with this type of parking brake operating device is described in Patent Document 1, for example.
Microfilm (No. 4-7, FIG. 1) of Japanese Utility Model No. 4-45280 (Japanese Utility Model Application No. 6-1078)

  As described above, in a work vehicle equipped with a conventional parking brake operating device, if the parking brake operating switch is operated or the engine is stopped, the parking brake device is operated so that the vehicle body does not move freely when the vehicle is stopped. Can be. However, in the process of handling work vehicles, it may be necessary to temporarily stop the vehicle with the engine running and get off, and in such cases, it is necessary to operate the parking brake operation switch one by one. If it is possible, it is desirable to avoid such an operation.

  For example, when stopping a work vehicle for a driver change, it is timely stopping, so it is troublesome for the driver to operate the parking brake operation switch one by one. There is a desire to be able to stop the vehicle safely without performing such operations. In the wheel loader, mud adheres to the bucket in the process of removing snow from the bucket, so it is necessary for the driver to temporarily stop and get off to remove the mud from the bucket. Considering the convenience of snow removal work, it is desired that the above operation is not necessary. In the wheel loader, the bucket is temporarily stopped and the bucket is replaced with various attachments. In this case, it is desirable that the parking brake operation switch need not be operated.

  This type of need also exists in work vehicles other than wheel loaders. For example, in a forklift, the driver may temporarily stop and get off at the time of work to adjust the position of the claw to adjust to the pallet (loading platform) width. Considering flights, it is desirable to be able to stop the vehicle safely without operating the parking brake operation switch. However, the conventional parking brake operating device for a work vehicle cannot meet the above needs.

  The invention of this application was created in order to solve the problems of the prior art, and the technical problem is that the driver temporarily stops the work vehicle with the engine running and gets off the vehicle. It is an object of the present invention to provide a parking brake operating device for a work vehicle that can automatically operate a parking brake device without operating a parking brake operating switch.

  In order to achieve the above technical problem, in the first invention of this application according to claim 1 of the claims, the means shown in the following 1) is adopted, and the second of this application according to claim 2 is adopted. In the second invention, the following means 2) is adopted.

1) A parking brake device, a brake operation circuit for operating the parking brake device, and a parking brake operation that can be opened and closed by a driver and can be operated and released through the brake operation circuit. A parking brake actuating device for a work vehicle, wherein the parking brake actuating switch is operated to operate the parking brake device so that a braking force can be applied to the work vehicle when stopped.
Each detection value of the seating detection means that can detect whether or not the driver is seated in the driver's seat, the vehicle speed detection means that can detect the speed of the work vehicle, and the detection value of the seating detection means and the vehicle speed detection means is input, and these detection Based on the value, a controller is provided that can determine whether the driver is not seated in the driver's seat and the work vehicle is in a stopped state, and is determined to be in such a state. When the engine of the work vehicle is operating, the parking brake device is operated through the brake operation circuit by outputting a control signal from the controller.

2) A parking brake device, a brake operation circuit for operating the parking brake device, and a parking brake operation that can be opened and closed by the driver and can be operated and released through the brake operation circuit. A parking brake actuating device for a work vehicle, wherein the parking brake actuating switch is operated to operate the parking brake device so that a braking force can be applied to the work vehicle when stopped.
Seating detection means that can detect whether the driver is seated in the driver's seat, forward / backward operation detection means that can detect whether the forward or backward operation of the work vehicle is being performed, and seating detection The detection values of the vehicle and the forward / reverse operation detection means are input, and based on these detection values, whether the driver is not seated in the driver's seat and the work vehicle is stopped traveling A controller that can determine whether or not the vehicle is in such a state, and outputs a control signal from the controller to operate the parking brake device through the brake operation circuit even when the engine of the work vehicle is in operation. To be configured.

  In the parking brake operating device for a work vehicle according to the first invention of this application, the means of 1) above is adopted. Therefore, when the work vehicle is stopped on a sloping ground or the like, the driver must operate the parking brake. By operating the switch, a braking force can be applied to the stopped working vehicle as in the conventional parking brake operating device. In addition, in this parking brake operating device, when the driver stops the work vehicle temporarily with the engine running, the parking brake operation switch can be operated without operating the parking brake operation switch. A braking force can be automatically applied.

  That is, the controller determines whether the driver is not seated in the driver's seat and the work vehicle is stopped traveling based on both detection values of the seating detection means and the vehicle speed detection means. Therefore, based on the determination result, it is possible to identify that the driver is about to get off the vehicle by stopping the work vehicle. When this is recognized, a control signal is output to output the parking brake. Activate the device. Therefore, according to this parking brake actuating device, it is possible to conveniently and safely perform a driver change or a short-time work outside the vehicle by temporarily stopping the work vehicle.

  In the parking brake operating device for a work vehicle according to the second invention of this application, the means of 2) above is adopted, so that the work vehicle being stopped is controlled by the same operation as the conventional parking brake operating device. In addition to being able to apply power, the same operational effects as the apparatus according to the first invention can be achieved. That is, in the controller, based on both detection values of the seating detection means and the forward / reverse operation detection means, whether the driver is not seated in the driver's seat and the work vehicle is in a stopped state. Therefore, based on the determination result, it can be identified that the driver is about to get off by stopping the work vehicle, and when this is identified, a control signal is output. Activate the parking brake device.

  As will be apparent from the following description, the parking brake actuating device for a work vehicle according to the first invention and the second invention of this application is shown in the section of [Means for Solving the Problems], respectively. Since the means of 1) and the means of 2) are adopted, when the driver temporarily stops the work vehicle with the engine running, the parking brake operation switch is not operated. The parking brake device can be activated automatically. Therefore, according to the parking brake actuating device according to both inventions, it is possible to conveniently and safely perform a driver change and a short-time work outside the vehicle by temporarily stopping the work vehicle.

  Hereinafter, how the invention of the present application is actualized will be described with reference to FIGS. 1 and 2 to clarify a desirable mode for carrying out the invention of the present application.

  FIG. 1 is a circuit diagram relating to a parking brake operating device for a wheel loader embodying the invention of this application, and FIG. 2 is a flowchart for explaining the operation of the parking brake operating device for the wheel loader shown in FIG. In these drawings, the invention of this application is shown as an example of a wheel loader parking brake operating device. However, the invention of this application is applied to a parking brake operating device of another work vehicle such as a forklift. Can also be applied.

  In these drawings, the portions denoted by the same reference numerals as those in FIG. 6 described above represent the same portions as those in FIG.

  The parking brake actuating device of the wheel loader of the following example embodying the invention of this application is the same as the parking brake actuating device of the conventional wheel loader described above, the parking brake drum 11, the brake pad 12, the links 13a and 13b. A parking brake device 10 having a parking brake cylinder 14, a hydraulic pump 2 and an electromagnetic direction switching valve 3, a brake operating circuit for operating the parking brake device 10, and an opening / closing operation performed by a driver. A parking brake operation switch 9 that can operate the parking brake device 10 and release the operation through a brake operation circuit, and operates the parking brake device switch 10 by operating the parking brake operation switch 9 to The braking force have to be able to grant to Ruroda, the basic structure is not the same as described above of the prior art devices.

  Hereinafter, the characteristic structure of the parking brake operating device of the wheel loader embodying the invention of this application will be mainly described. Since the technical content of the parking brake operating device can be applied to a parking brake operating device for a work vehicle other than a wheel loader, this will be described with reference to this as appropriate.

  In FIG. 1, 15 is a seating detection sensor as seating detection means that can detect whether or not the driver is seated in the driver's seat 30, and 16 is a vehicle speed detection means that can detect the speed of the wheel loader. The vehicle speed detection sensor 17 is a forward / reverse changeover switch serving as a forward / reverse operation detecting means that can detect whether the forward operation or reverse operation of the wheel loader is being performed, 18 is a seating detection sensor 15, The detection results of the vehicle speed detection sensor 16 and the forward / reverse selector switch 17 are input, and based on these detection results, the driver is not seated in the driver's seat 30 and the wheel loader has stopped traveling. It is a controller that can determine whether or not it is in a state.

  For the seating detection sensor 15, for example, a switch that is closed (turned on) by the weight of the driver when the driver is seated in the driver's seat 30 is used. When the driver operates the forward / reverse switching lever 34 in FIG. 5 in order to move the wheel loader forward, backward, and stop, the forward / backward changeover switch 17 corresponds to the forward position, the reverse position, and the neutral position. It can be switched to stages. Since the seating detection sensor 15 is not normally provided in a work vehicle such as a wheel loader, it is necessary to newly install it. Since the vehicle speed detection sensor 16 and the forward / reverse selector switch 17 are the devices normally provided in the wheel loader in order to display the operation status of the wheel loader in the driver's cab 26, the existing devices of the wheel loader should be used. Can do. Since the vehicle speed detection sensor 16 and the forward / reverse selector switch 17 are usually provided in most work vehicles, existing equipment can be used in work vehicles other than wheel loaders.

  The controller 18 determines whether or not the driver is not seated in the driver's seat 30 as described above and the wheel loader has stopped traveling, that is, whether or not the driver is ready to get off. In the wheel loader, due to the nature of the work, the detection result of the seating detection sensor 15 does not detect the driver's seating, the detection value of the vehicle speed detection sensor 16 is zero, and the forward / reverse selector switch When the detection result at 17 is in the neutral position, it is best to determine that the driver is ready to get off.

  The reason for this is that in the wheel loader, the driver may perform the work on the middle waist while traveling, so that the detection result of the seating detection sensor 15 does not detect the driver's seating. The driver cannot be determined to be ready to get off. Therefore, it is confirmed that the wheel loader has stopped traveling by detecting that the detection value of the vehicle speed detection sensor 16 is zero. However, in the wheel loader, the excavation and snow removal are performed while the bucket 25b is digging into the earth and sand and the snow by the forward force during traveling in the earth and sand excavation work and snow removal work. is there. For this reason, it may not be said that the driver is in a starting position for getting off simply by detecting that the detection value of the vehicle speed detection sensor 16 is zero. For this reason, the forward / reverse selector switch 17 is used to confirm that the excavation work and the snow removal work as described above are not performed and to determine that the driver is ready to get off the vehicle. One of the conditions for determining that the driver is in a starting position for getting off the vehicle is that the detection result is in the neutral position, that is, neither forward driving nor reverse driving is performed. In addition, apart from when the wheel loader is stopped in earnest, the vehicle speed becomes zero when the detection result at the forward / reverse selector switch 17 is in the neutral position in a state where the wheel loader is in operation. In practice this is not possible.

  In the example shown here, when the controller 18 determines that the driver is ready to get off with the above conditions as the determination conditions, a control signal is output from the controller 18 to turn on the solenoid of the direction switching valve 3. I try to degauss. Thus, the direction switching valve 3 is switched to the left position shown in FIG. 1 so that the parking brake device 10 is operated through the brake operation circuit even when the wheel loader engine is in an operating state. . It should be noted that a general work vehicle does not perform special work such as a wheel loader, so that the detection result of the seating detection sensor 15 does not detect the driver's seating and the detection value of the vehicle speed detection sensor 16 There is no practical problem even if the driver determines that the vehicle is in the starting position for getting off the vehicle, and that the detection result of the forward / reverse selector switch 17 is in the neutral position.

  Next, the operation of the parking load actuating device for such a wheel loader will be described with reference to FIG.

  If the parking brake operation switch 9 is opened and turned off while the wheel loader engine is in operation, the parking brake device 10 immediately operates as in the case of the conventional parking brake operation device, and the stopped wheel loader is controlled. Power can be applied. On the other hand, when the parking brake operation switch 9 is not opened and is turned on, the controller 18 determines whether or not the driver is seated on the driver's seat 30 based on the detection result of the seating detection sensor 15. judge. As a result, when it is determined that the user is seated, the parking brake device 10 remains released. On the other hand, when it is determined that the driver is not seated in the driver's seat 30, this time, the controller 18 determines whether or not the vehicle speed is zero based on the detection value of the vehicle speed detection sensor 16. As a result, when it is determined that the vehicle speed is not zero, the parking brake device 10 is still released.

  On the other hand, when it is determined that the vehicle speed is zero, the controller 18 determines whether the changeover switch 17 is in the neutral position, the forward position or the reverse position based on the detection result of the forward / reverse changeover switch 17. Judge with. As a result, when it is determined that the vehicle is in either the forward position or the reverse position, the parking brake device 10 is still released. On the other hand, when it is determined that the forward / reverse selector switch 17 is in the neutral position, a control signal is output from the controller 18 to automatically activate the parking brake device 10 even when the driver does not open the parking brake operation switch 9. To operate.

  As described above, in the parking brake operating device of the wheel loader, when the wheel loader stops in earnest on an inclined ground or the like, the driver operates the parking brake operating switch 9 so that it is the same as the conventional parking brake operating device. The braking force can be applied to the stopped working vehicle. In addition, when the driver stops the wheel loader temporarily with the engine running, the parking brake device 10 is automatically activated without the driver operating the parking brake operation switch 9. It is possible to apply a braking force to the wheel loader that is operating and stopped. Further, when the driver gets on again and sits in the driver's seat 30, the operation of the parking brake device 10 can be automatically released without the driver operating the parking brake operation switch 9. Therefore, according to this parking brake operating device, it is possible to conveniently and safely perform a driver change and a short-time operation outside the vehicle by temporarily stopping the wheel loader.

It is a circuit diagram regarding a parking brake operating device of a wheel loader embodying the invention of this application. It is a flowchart for demonstrating an effect | action of the parking brake actuator of the wheel loader of FIG. It is a side view which shows the whole wheel loader conventionally implemented by the applicant. It is a top view of the wheel loader of FIG. It is a top view which shows the state of the driver's seat vicinity of the wheel loader of FIG. It is a circuit diagram regarding the parking brake operating device of the wheel loader that the applicant has conventionally implemented.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic oil tank 2 Hydraulic pump 3 Electromagnetic direction switching valve 9 Parking brake operation switch 10 Parking brake apparatus 11 Parking brake drum 12 Brake pad 12a Spring 13a First link 13b Second link 14 Parking brake cylinder 14a Spring 15 Seating Detection sensor 16 Vehicle speed detection sensor 17 Forward / reverse selector switch 18 Controller 30 Driver's seat 34 Forward / reverse selector lever

Claims (2)

  A parking brake device, a brake operating circuit for operating the parking brake device, a parking brake operating switch that can be opened and closed by a driver and can be operated or released through the brake operating circuit; Whether the driver is seated in the driver's seat in a parking brake operating device for a work vehicle that is capable of applying a braking force to the work vehicle when the vehicle is stopped by operating the parking brake operation switch by operating a parking brake operation switch Seat detection means that can detect whether or not, vehicle speed detection means that can detect the speed of the work vehicle, and detection values of the seat detection means and the vehicle speed detection means are inputted, and based on these detection values, the driver Whether or not the work vehicle is in a state of stopping traveling By providing a controller capable of determining, and outputting a control signal from the controller when it is determined to be in such a state, the parking brake device is operated through the brake operating circuit even when the engine of the work vehicle is operating. A parking brake actuating device for a work vehicle, characterized in that it is configured.   A parking brake device, a brake operating circuit for operating the parking brake device, a parking brake operating switch that can be opened and closed by a driver and can be operated and released through the brake operating circuit; Whether the driver is seated in the driver's seat in a parking brake operating device for a work vehicle that can apply a braking force to the work vehicle when the vehicle is stopped by operating the parking brake operation switch by operating a parking brake operation switch Each detection of a seating detection means capable of detecting whether or not, a forward / backward operation detection means capable of detecting whether a forward operation or reverse operation of the work vehicle is being performed, and a detection of the seating detection means and the forward / backward operation detection means Values are entered and based on these detected values, the driver sits in the driver's seat And a controller that can determine whether or not the work vehicle is in a stopped state, and outputs a control signal from the controller when it is determined that the work vehicle is in such a state. A parking brake operating device for a work vehicle, wherein the parking brake device is operated through a brake operating circuit even when the engine is in an operating state.

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