JPS61106833A - Bucket levelling device for loading and unloading vehicle - Google Patents

Abstract

PURPOSE:To simplify levelling of a bucket, by a method wherein, during control of a damp cylinder, a control signal is outputted to a control valve in priority to or through addition to a correction control signal. CONSTITUTION:According to a detecting signal from an arm angle sensor 10 and a detecting signal from a bucket angle sensor 11, the angles of a lift arm and a bucket are computed, and the two angles are compared with bucket angle holding data in memories 18 and 28 to compute a correction signal necessary to levelling of the bucket. During control of a control pedal 15 of a damp cylinder 9, the output of a control signal from the pedal 15 is outputted to a control valve 19 of the cylinder 9 in priority of the control signal to a correction control signal or addition to the correction control signal. During control of a control pedal 17 of a lift cylinder 6, a control signal for the pedal 17 is outputted to a control valve part 20 of the lift cylinder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a bucket leveling device for a shovel in a cargo handling vehicle such as a skid steer shovel or a shovel loader.

(Prior Art) A conventional bucket leveling device for a skid steer excavator will be described with reference to FIG. 17. A pair of support plate portions 32 are provided on both sides of the rear end of a vehicle body frame 31 to protrude upward. A pair of lift arms 3 are provided on the upper part of each support plate part 32.
3 is rotatably supported vertically, and a base end portion of a lift cylinder 34 is rotatably supported at the bottom of each support plate portion 32 . The tip of the lift cylinder 34 is rotatably supported at the center of the lift arm 33.

The center portion of each of the lift arms 33 near the tip is bent downward, and a bucket 35 is rotatably supported at the tip on both sides of the rear end. A bracket 36 is rotatably supported on the bent portion of the lift arm 33, and a base end of a dump cylinder 37 is rotatably supported on the bracket 36. Same dump cylinder 3
The tip end of the bucket 35 is rotatably supported on the upper part of the rear end of the bucket 35.

A leveling link 38 is rotatably supported between the support plate portion 32 and the bracket 36 at both ends thereof, and the leveling link 38 of the lift arm 33 is rotatably supported at both ends thereof.
8. Bracket 36. A parallel link was configured from the support plate portion 32. And lift cylinder 34
When the bucket 35 is operated, even if the lift arm 33 moves up and down, the attitude of the bucket 35 does not change due to the parallel link.

(Problems to be Solved by the Invention) However, as described above, since the brackets 36 and (bearing links 38) must be provided, there is a problem that there are significant restrictions in terms of design layout and strength, and There is a problem that assembly is troublesome and the weight of the entire vehicle increases.

In addition, some vehicles are not provided with the leveling link 38, but in this type of vehicle, the operator must always maintain the attitude of the bucket 35 when raising or lowering the lift arm 33. This has to be done under control, making the work very troublesome and complicated.

Structure of the Invention (Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and the bucket leveling device of the present invention uses a lift cylinder to raise and lower a vehicle body frame, a chain arm, etc. A cargo handling vehicle "1" is provided with a lift arm that operates, and a bucket that is rotated up and down by a dump cylinder at the tip of the lift arm; and a dump cylinder operating means □ for operating the dump cylinder by smell. , a lift cylinder operating means for operating the lift cylinder, a lift arm movement sensor for detecting the movement amount of the lift arm, a bucket movement sensor for detecting the movement amount of the bucket, and a bucket angle holding data. The storage memory, the detection signals detected by the lift arm movement sensor at each time, and the detection signals detected by the bucket movement sensor at each time are input, and the angle of the lift arm and the angle of the bucket are determined based on each detection signal. and leveling of the bucket corresponding to the rotation angle of the lift arm at that time by comparing both angles calculated by the first calculation means with the bucket angle holding data in the memory. a second calculation means for calculating the amount of operation of the dump cylinder necessary for the operation; and when the dump cylinder operation means is operated, the output of the operation signal of the dump cylinder operation means is corrected based on the amount of operation calculated by the second calculation means. a first drive control means that allows output of a signal obtained by adding the operation signal of the dump cylinder operation means to the correction control signal to the control valve section of the dump cylinder with priority over the control signal; and the lift cylinder operation means. The gist thereof is that the second drive control means outputs an operation signal of the lift cylinder operating means to the control valve section of the lift cylinder when the means is operated.

(Function) With the above configuration, the detection signals detected by the lift arm movement amount sensor from time to time and the detection signals detected from the bucket movement amount sensor from time to time are inputted, and the angle of the lift arm is determined based on each detection signal. A first calculation means calculates the angle of the bucket. Then, the second calculation means compares both the calculated angles with the bucket angle holding data in the memory and operates the dump cylinder necessary for leveling the bucket corresponding to the rotation angle of the lift arm at that time. Calculate quantities.

When the dump cylinder operating means is operated, the first drive control means outputs the operation signal of the dump cylinder operating means with priority over the correction control signal based on the operation amount of the dump cylinder calculated by the calculation means, or A signal obtained by adding the operation signal of the cylinder operation means to the correction control signal is output to the control valve section of the dump cylinder.

Further, when the lift cylinder operating means is operated, the second drive control means outputs an operating signal of the lift cylinder operating means to the control valve section of the lift cylinder.

(Embodiments) First Embodiment A first embodiment in which the present invention is embodied in a skid steer shovel will be described below with reference to FIGS. 1 to 4.

A front wheel 2 and a rear wheel 3 are provided on the lower surfaces of the front and rear ends of the vehicle body frame 1, respectively, and a pair of support plate portions 4 are provided on both sides of the rear end of the vehicle body frame 1 to protrude upward. A pair of lift arms 5 are rotatably supported on the upper part of each support plate part 4, and a base end of a lift cylinder 6 is rotatably supported on the lower part of each support plate part 4. ing.

The tip of the lift cylinder 6 is rotatably supported by the center of the lift arm 5.

The central portion of each of the lift arms 5 near the tip is bent downward as shown in FIG. There is. A bracket 8 is fixed to the bent portion of the lift arm 5, and a base end of a dump cylinder 9 is rotatably supported on the bracket 8. The tip of the dump cylinder 9 is rotatably supported on the upper part of the rear end of the bucket 7.

An arm angle sensor 10 as a lift arm movement amount sensor is provided at the base end of the lift arm 5, and the arm angle sensor 10 detects the movement amount, that is, the rotation angle of the lift arm 5. Further, a bucket angle sensor 11 as a bucket movement amount sensor is provided at the pivot point of the bucket 7 at the tip of the lift arm 5, and detects the movement amount, that is, the rotation angle of the bucket 7.

Next, an electric circuit provided in the skid steer shovel constructed as described above will be explained with reference to FIG.

The dump pedal opening sensor 14 consists of a potentiometer, and the dump pedal 15 serves as a dump cylinder operating means.
Detects the amount of depression. Also, lift pedal opening sensor 1
Numeral 6 also includes a potentiometer, which detects the amount of depression of the lift pedal 17, which serves as a start command means for instructing the start of bucket leveling and a lift cylinder operating means.

A central processing unit (hereinafter referred to as
CPU) is driven based on the control program stored in the ROM 28, and also controls each of the arm angle sensors 10. Bucket angle sensor 11. Each detection signal from the dump pedal opening sensor 14 and the lift pedal opening sensor 16 is input.

The CPU 13 uses the arm angle sensor 1 that is input from time to time.
0 and the rain detection signal from the bucket angle sensor 11, the amount of rotation of the lift arm 5 and the bucket 7, that is, the rotation angle is calculated. Further, the CPU 13 uses detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input at the time when the operation of the dump pedal 15 is completed, that is, when the bucket 7 has finished rotating by the dump cylinder 9. Memory 18 (hereinafter referred to as RAM) that can read and rewrite the rotation angles of the lift arm 5 and bucket 7 at that time as bucket angle holding data
Store in.

Further, the CPU 13 determines whether or not the lift pedal 17 is depressed, and if it is determined that the lift pedal 17 is depressed, calculates the amount of depression of the lift pedal 17, and calculates the distance between the lift pedals at that time. A proportional operating signal is output to the control valve 20 of the lift cylinder 6 via the interface 12. The control valve 20 drives and controls the lift cylinder 6 based on an operation signal from the CPU 3.

Next, the CPtJ13 determines whether or not the dump pedal 15 is depressed, and if it is determined that the dump pedal 15 is depressed, the CPU 13 resets the angle holding data and adjusts the dump cylinder according to the amount of depression of the dump pedal 15. The operation amount is calculated, and an operation signal proportional to the dump pedal opening amount at that time is output to the control valve 19 of the dump cylinder 9 via the interface 12. The core roll valve 19 drives and controls the dump cylinder 9 based on an operation signal output from the CPU 13.

On the other hand, when the CPIJ 13 determines that the dump pedal 15 is not depressed, it reads out the bucket angle holding data stored in the RAM 18 and detects the arm angle sensor 0 and the bucket angle sensor 1 that are input from time to time. The rotation angle of the lift arm 5 and bucket 7 based on the signal is compared with the bucket angle holding data, and the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time is determined. The operation amount is calculated, and a correction control signal based on the operation amount is output to the control valve 19 of the dump cylinder 9 via the interface 12.

13. On the other hand, if it is determined that the lift pedal 17 is not depressed, then it is determined whether or not the dump pedal 15 is depressed, and if it is determined that the dump pedal 15 is depressed, then the The dump cylinder operation amount is calculated, and an operation signal proportional to the dump pedal opening amount at that time is output to the control valve 19 of the dump cylinder 9 via the interface 12. The control valve 19 drives and controls the dump cylinder 9 based on an operation signal output from the CPU 13.

Next, the operation of the skid steer shovel constructed as described above will be explained.

Now, when only the dump pedal 15 is depressed so that the bucket 7 rotates upward from the state indicated by the solid line in FIG. It is input to the CPU 13. Then, the CPU 13 calculates the amount of depression of the dance pedal 15 based on the detection signal of the dump pedal opening sensor 14, and interfaces the operation signal proportional to the dump pedal opening amount at that time to the control valve 19 of the dump cylinder 9. output via 12.

As a result, the control valve 19 controls and drives the dump cylinder 9 in response to the manipulation signal, thereby rotating the bucket 7 upward.

At this time, the CPtJ 13 calculates the amount of rotation, that is, the rotation angle, of the lift arm 5 and the bucket 7 based on the rain detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input from time to time.

Then, when the depression operation of the dump pedal 15 is completed, the arm angle sensor inputted at the time when the depression operation is completed (that is, when the bucket 7 finishes rotating by the dump cylinder 9, the state shown by the chain line in FIG. 1) The rotation angles of the lift arm 5 and the bucket 7 at that time based on the detection signals from the lift arm 5 and the bucket angle sensor 11 are stored in the RAM 18 as bucket angle holding data.

Next, when the bucket 7 is in the state shown by the chain line in FIG. via CPtJ
13. The CP (Jl 3) calculates the amount of depression of the lift pedal 17 based on the detection signal of the lift pedal opening sensor 16, and sends an operation signal proportional to the distance between the lift pedals to the control valve of the lift cylinder 6. 20 via the interface 12.

As a result, the control valve 20 controls and drives the lift cylinder 6 in response to the lift operation signal, and rotates the lift arm 5 upward.

At this time, the CPU 13 determines whether or not the dump pedal 15 is depressed, and if it determines that the dump pedal 15 is depressed, the CPU 13 resets the angle holding data and adjusts the dump cylinder according to the amount of depression of the dump pedal 15. The operation amount is calculated, and an operation signal proportional to the dump pedal opening amount at that time is output to the control valve 19 of the dump cylinder 9 via the interface 12. The control valve 19 drives and controls the dump cylinder 9 based on the operation signal output from the CPIJ 13.

On the other hand, when the CPtJ13 determines that the dump pedal 15 is not depressed, it reads the bucket angle holding data stored in the RAM 18, and reads out the bucket angle holding data stored in the RAM 18, based on the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input from time to time. The rotation angle of the lift arm 5 and the bucket 7 at that time is compared with the bucket angle holding data, and the operation of the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time is performed. A correction control signal based on the operation amount is output to the control valve 19 of the dump cylinder 9 via the interface 12.

As a result, the control valve 19 drives and controls the dump cylinder 9 based on the correction control signal from the CPU 13, and maintains the attitude of the bucket 7 in the same state as the chain line in FIG. 1, as shown in FIG. Move upwards.

``In order to return the state shown in FIG. 2 to the state shown in FIG. It moves downward together with the lift arm 5 while maintaining its posture by the cylinder 9.

In this way, unlike the conventional method, the bucket 7 can be easily leveled without using a parallel link and without requiring the operator to operate the lift arm 5 while controlling the attitude of the bucket 7 himself.

Next, as a modification of the first embodiment, the following configuration may be adopted.

In the first embodiment, when the CPU 13 depresses the dump pedal 15 as a dump cylinder operating means, the CPU 13 outputs C.
The PU 13 resets the angle holding data and calculates the depression amount of the dump pedal 15 with priority, and at that time outputs an operation signal proportional to the dump pedal opening amount to the control valve 19 of the dump cylinder 9. CP to
U13 is configured to add an operation signal proportional to the current distance of the dump pedal to the correction control signal and output the result to the control valve 19 of the dump cylinder 9.

In the first embodiment, the lift pedal 17 is used as the leveling start command means, but instead, no leveling start command means is provided and the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 are constantly transmitted to the CPLI 1.
3 is input, the operation amount of the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time is calculated in the same manner as in the first embodiment, and the operation amount is calculated based on the operation amount. The correction control signal is sent to the interface, S12.
The configuration is such that the output signal is output to the dump syringe 99 control valve 19 via the dump syringe 99 control valve 19.

Therefore, the flowchart when the dump pedal 15 is depressed in this first modification is as shown in FIG.

Second example Next, a second embodiment will be described with reference to FIGS. 6 and 7.

Note that the same reference numerals are given to the same or corresponding configurations as those of the first embodiment, and the explanation thereof will be omitted.

In this embodiment, in the configuration of the first embodiment, a lift cylinder stroke sensor 21 for detecting the stroke movement amount of the lift cylinder 6 is provided as a lift arm movement amount sensor instead of the arm angle sensor 10, corresponding to the lift cylinder 6. The only difference is that instead of the bucket angle sensor 11, a dump cylinder stroke sensor 22 for detecting the amount of stroke movement of the dump cylinder 9 is placed close to the dump cylinder 9 as a bucket movement sensor. There is.

Therefore, in this second embodiment, the CPU 13 controls the lift arm 5 based on the rain detection signals from the lift cylinder stroke sensor 21 and the dump cylinder stroke sensor 22.
Then, the amount of rotation of the bucket 7, that is, the rotation angle is calculated.

Third Embodiment Next, a third embodiment will be explained with reference to FIGS. 8 and 9.

In this embodiment, the control valve section of the dump cylinder 9 is a main control valve 23 which inputs a detection signal detected by the dump pedal opening sensor 14 of the dump pedal 15.
, a sub-control valve 24 that inputs a correction control signal from the CPU 13, and the main control valve 2.
3 and the sub control valve 24, and the CPLI
The switching valve 25 selectively connects the main control valve 23 or the auxiliary control valve 24 to the dump cylinder 9 in response to a switching signal output from the dump cylinder 13. Furthermore, when the dump pedal 15 is depressed, the CPU 13 inputs the detection signal from the dump pedal opening sensor 14, and based on the detection signal, switches the switching signal to switch the switching valve 25 to the main control valve 23 side. It is output to the valve 25.Then, the CP'L113 resets the angle holding data and calculates the dump cylinder operation amount according to the dump pedal depression amount, and then outputs an operation signal proportional to the dump pedal opening amount. is output to the main control valve 23 via the interface 12.The main control valve 23 outputs the CP
The dump cylinder 9 is driven by the operation signal output from L113.

Further, when the dump pedal 15 is not depressed V1, the CPU 13 outputs a switching signal to the switching valve 25 to switch the switching valve 25 to the auxiliary control valve 24 side. Then, the bucket angle holding data stored in the RAM 18 is read out, and the rotation angles of the lift arm 5 and the bucket 7 are calculated based on the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input from time to time. Compare the bucket angle holding data, calculate the operation amount of the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time, and generate a correction control signal based on the operation amount. It is output to the auxiliary control valve 24 of the dump cylinder 9 via the interface 12. The difference from the first embodiment is that the sub control valve 24 drives the dump cylinder 9 in response to a correction control signal output from the CPU 13.

Therefore, in this embodiment, when the lift pedal 17 is depressed so that the bucket 7 rotates the lift arm 5 upward, a detection signal from the lift pedal opening sensor 16 is input to the CPU 13 via the interface 12. . The CPU 13 then controls the lift pedal opening sensor 1.
The amount of depression of the lift pedal 17 is calculated based on the detection signal of the lift cylinder 6, and an operation signal proportional to the amount of lift pedal opening at that time is sent to the control valve 20 of the lift cylinder 6.
The data is outputted via the interface 12.

As a result, the control valve 20 controls and drives the lift cylinder 6 in response to the lift operation signal, and rotates the lift arm 5 upward.

At this time, the CPU 13 reads the amount of depression of the dump pedal and roughly determines whether the dump pedal 15 is being depressed. When determining that the dump pedal 15 is depressed, the CPtJ 13 resets the angle holding data, calculates the amount of dump cylinder operation corresponding to the moment when the dump pedal is depressed, and outputs an operation signal proportional to the amount of dump pedal opening at that time. It outputs to the main control valve 23 via the interface 12. The main control valve 23
drives the redump cylinder 9 based on the operation signal output from the CPU 13.

Further, when the dump pedal 15 is not depressed, the CPU 13 controls the switching valve 25 to
outputs a switching signal to switch the control valve to the sub-control valve 24 side. Then, the bucket angle holding data stored in the RAM 18 is read out, and the lift arm 5 and bucket 7 are selected based on the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input from time to time.
Compare the rotation angle of and the bucket angle holding data,
The amount of operation of the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time is calculated, and a correction control signal based on the amount of operation is sent to the secondary of the dump cylinder 9 via the interface 12. Output to control valve 24. The auxiliary control valve 24 drives the dump cylinder 9 based on the correction control signal output from the CPU 13.

In addition, in the third embodiment, the switching valve 25 is operated by the CPU 13.
The main control valve 23 or the auxiliary control valve 24 is selectively connected to the dump cylinder 9 by a switching signal output from the switch. You may.

That is, when the dump pedal 15 is depressed, the CPU 13 inputs a detection signal from the dump pedal opening sensor 14, and controls the switching valve 25 based on the detection signal.
A switching signal is output to the switching valve 25 to switch the control valve to the merging side with the main control valve 23 and the sub-control valve 24. Further, when the dump pedal 15 is not depressed, the CPU 13 controls the switching valve 25 as a sub-controller.
/lz /E /L/ 724 side′″+J) @
;h 6 tJ) M*? 'i 'i: :ni3''
1 is supposed to be done.

Therefore, in this modification, when the dump pedal 15 is depressed, the CPU 13 outputs a switching signal to the switching valve 25, and switches the switching valve 25 to the main control valve 25.
3 and the auxiliary control valve 24. Then, the dump cylinder 9 is controlled and driven based on the result of adding the detection signal from the dump pedal opening sensor 14 and the correction control signal from the CPU 13.

In addition, when only the lift pedal 17 is depressed, the dump pedal 15 is not depressed, so the CPU 1
3 outputs a switching signal to the switching valve 25 to switch the switching valve 25 to the sub-control valve 24 side.

Figures 10 and 11 roughly explain the modification of the third embodiment.
This will be explained according to the diagram.

In this modification, the switching valve 25 is omitted from the configuration of the third embodiment, and the main control valve 23 and the sub-control valve 24 are merged and connected to the dump cylinder 9.

When the lift pedal 17 is depressed, the CPIJ 13 calculates the amount of depression of the lift pedal 17 based on the detection signal of the lift pedal opening sensor 16, and sends an operation signal proportional to the lift pedal opening amount to the lift pedal. It outputs to the control valve 20 of the cylinder 6 via the interface 12.

At this time, the CPU 13 reads the bucket angle holding data stored in the RAM 18, reads the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input from time to time, and adjusts the lift arm 5 at the time based on the detection signals. The rotation angle of the bucket 7 and the bucket angle holding data are compared, and the lift arm 5 at that time is
calculates the amount of operation of the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of , and outputs a correction control signal based on the amount of operation to the sub control valve 24 of the dump cylinder 9 via the interface 12. It looks like this.

Further, the CPU 13 calculates a dump cylinder operation amount according to the amount of depression of the dump pedal, and outputs an operation signal based on the operation amount to the main control valve.

Accordingly, in this modification, the bucket 7 is connected to the lift arm 5.
When the lift pedal 17 is depressed so as to rotate upward, the CPU 3 calculates the amount of depression of the lift pedal 17 based on the detection signal of the lift pedal opening sensor 16, and calculates the amount of depression of the lift pedal 17 in proportion to the amount of lift pedal opening at that time. The generated operation signal is output to the control valve 20 of the lift cylinder 6.

As a result, the control valve 20 controls and drives the lift cylinder 6 in response to the lift operation signal, and rotates the lift arm 5 upward.

At this time, the CPU 13 reads the bucket angle holding data stored in the RAM 18, reads the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 that are input from time to time, and adjusts the lift arm 5 and position at the time based on the detection signals. The rotation angle of the bucket 7 is compared with the bucket angle holding data, and the operation amount of the dump cylinder 9 necessary for leveling the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time is calculated. A correction control signal based on this is output to the sub control valve 24 of the dump cylinder 9 via the interface 12.

Further, the CPU 13 calculates the amount of operation of the dump cylinder according to the amount of depression of the dump pedal, and outputs an operation signal based on the amount of operation to the main control valve. It is driven by 24 control valves.

Other operations are similar to those of the third embodiment.

Fourth Embodiment Next, a fourth embodiment will be explained with reference to FIGS. 12 to 14.

In this embodiment, in addition to the control program stored in the ROM 28 in the configuration of the first embodiment, the rotation angle of the bucket 7 when the bucket 7 is in a horizontal state is stored in advance. The difference is that fJ angle 8'771 is stored in advance as angle holding data.

In this embodiment, the horizontal state of the bucket 7 refers to the state in which the front plate 7a of the bucket 7 is horizontal, ie, the state when scooping earth and sand, etc., as shown in FIG.

Therefore, in this embodiment, when the lift pedal 17 is depressed to the lowering side or the floating state, the lift arm 5
As the bucket 7 moves downward, the bucket 7 maintains a horizontal state as shown in FIGS. 12 and 13, and is leveled.
Guiding will be carried out.

Fifth Embodiment Next, a fifth embodiment will be explained with reference to FIGS. 15 and 16.

In this embodiment, in addition to the configuration of the first embodiment, a CPU
13 is provided with a ROM 26, in which the rotation angle of the bucket 7 when the bucket 7 is in a horizontal state and the rotation angle of the lift arm 5 are stored in advance as bucket angle holding data. Further, the lift pedal 17 for instructing the start of bucket leveling in the first embodiment is used as the first start command means, and in addition to this configuration, a push button 27 for instructing the start of bucket leveling to maintain the bucket 7 in a horizontal state is used. is used as the second start command means.

When the lift pedal 17, which is the first start command means, is depressed, the CPU 13 controls the bucket 7 to be leveled in the same way as in the first embodiment. Turn on the push button switch 27, which is the second start command means.
Then, the dump cylinder 9 is controlled and driven to maintain the bucket 7 in a horizontal state.

Other operations are similar to those in the first embodiment.

Therefore, in this embodiment, by appropriately selecting the first start command means and the second start command means, it is possible to level the bucket 7 in accordance with the work content.

More than just the effects of the invention, as detailed above, this invention is a bucket! - Since parallel links are not used for leveling of the bucket, constraints in terms of design layout and strength are eliminated, assembly is less troublesome than before, and the weight of the vehicle can be reduced, making it possible to level the bucket. It is an excellent invention for industrial use because it is easy to carry out and has good effects.

[Brief explanation of the drawing]

Fig. 1 is a side view of a cargo handling vehicle according to a first embodiment of the present invention, Fig. 2 is a side view when the lift arm is moved upward from the state shown in Fig. 1, and Fig. 3 is an electric block circuit diagram. 4 is a flowchart for explaining the processing operation of the central processing unit (CPU), FIG. 5 is a floating state of a modification of the first embodiment, and FIG. 6 is a side view of the cargo handling vehicle of the second embodiment. FIG. 7 is the same electric block circuit diagram, FIG. 8 is the electric block circuit diagram of the third embodiment, and FIG. 9 is the same central processing unit (
A flowchart for explaining the processing operation of the CPU,
FIG. 10 is an electrical block circuit diagram showing a modification of the third embodiment, FIG. 11 is a flowchart, and FIG. 12 is a fourth embodiment.
A side view when the lift arm of the cargo handling vehicle of the example is raised,
Fig. 13 is a side view when the lift arm is moved downward from the state shown in Fig. 12, Fig. 14 is an electrical block circuit diagram, Fig. 15 is an electrical block circuit diagram of the fifth embodiment, and Fig. 16 is the same central view. A flowchart for explaining the processing operation of the processing device (CPU), and FIG. 17 is a side view of a conventional cargo handling vehicle. 1 is a vehicle body frame, 5 is a lift arm, 6 is a lift cylinder, 7 is a bucket, 9 is a dump cylinder, 10 is an arm angle sensor, 11 is a bucket angle sensor, 12 is an interface, 13 is a central processing bag @ (CPU), 14 is a dump pedal opening sensor, 15 is a dump pedal, 16 is a lift pedal opening sensor, 17 is a lift pedal, and 18 is a RAM. 19 is a control valve, 20 is a control valve, 21 is a lift cylinder stroke sensor, 22 is a dump cylinder stroke sensor, 23 is a main control valve, 24 is a sub control valve, 25 is a switching valve, 27 is a push button switch, 28 is R ,0,M. 1 Patent Applicant: Toyota Automatic Oridan Manufacturing Co., Ltd.□
゛□゛ (Representative Patent Attorney On 1) Hironobu Diagram 1

Claims (1)

[Scope of Claims] 1. In a cargo handling vehicle in which a lift arm is provided on the vehicle body frame, reach arm, etc. to be raised and lowered by a lift cylinder, and a bucket is provided at the tip of the lift arm to be rotated up and down by a dump cylinder. , a dump cylinder operating means for operating the dump cylinder; a lift cylinder operating means for operating the lift cylinder; a lift arm movement sensor for detecting the amount of movement of the lift arm; and the amount of movement of the bucket. A bucket movement sensor that detects the bucket angle, a memory that stores bucket angle holding data, a detection signal detected by the lift arm movement sensor from time to time, and a detection signal detected by the bucket movement sensor from time to time are input, a first calculating means for calculating the angle of the lift arm and the angle of the bucket based on each detection signal; and comparing both angles calculated by the first calculating means with bucket angle holding data in the memory. a second calculation means for calculating the operation amount of the dump cylinder necessary for leveling the bucket corresponding to the rotation angle of the lift arm; A signal obtained by adding the operation signal of the dump cylinder operating means to the correction control signal is output to the control valve section of the dump cylinder with priority over the correction control signal based on the operation amount calculated by the second calculation means. and a second drive control means that outputs an operation signal for the lift cylinder operation means to a control valve section of the lift cylinder when the lift cylinder operation means is operated. Bucket leveling device for cargo handling vehicles. 2. The bucket leveling device for a cargo handling vehicle according to claim 1, wherein the lift arm movement amount sensor is an arm angle sensor that detects a rotation angle of the lift arm. 3. Claim 1, wherein the bucket movement amount sensor is a bucket angle sensor that detects the rotation angle of the bucket.
A bucket leveling device for a cargo handling vehicle according to item 1 or 2. 4. The bucket leveling device for a cargo handling vehicle according to claim 1 or 3, wherein the lift arm movement amount sensor is a lift cylinder stroke sensor that detects the amount of movement of the stroke of the lift cylinder. 5. The bucket leveling device for a cargo handling vehicle according to claim 4, wherein the bucket movement amount sensor is a dump cylinder stroke sensor that detects the amount of stroke movement of the dump cylinder. 6. The control valve section of the dump cylinder includes: a main control valve that inputs an operation signal from the dump cylinder operating means; a sub-control valve that inputs a correction control signal from the first drive control means; and the main control valve. and the auxiliary control valve, and by a switching signal from the first drive control means,
Claim 1 comprising a switching valve that switches to the main control valve when the dump cylinder operating means is operated, and switches to the auxiliary control valve when the dump cylinder operating means is not operated. A bucket leveling device in a cargo handling vehicle described in . 7. The control valve section of the dump cylinder includes: a main control valve that inputs an operation signal from the dump cylinder operating means; a sub-control valve that inputs a correction control signal from the first drive control means; and the main control valve. and the auxiliary control valve, and by a switching signal from the first drive control means,
It is composed of a switching valve that switches to the confluence side of the main control valve and the auxiliary control valve when the dump cylinder operating means is operated, and switches to the auxiliary control valve when the dump cylinder operating means is not operated. A bucket leveling device for a cargo handling vehicle according to claim 1. 8. The memory is a readable and rewritable memory that stores detection signals detected by the lift arm movement amount sensor and the bucket movement amount sensor as bucket angle holding data when the operation of the dump cylinder operating means is completed. A bucket leveling device for a cargo handling vehicle according to any one of items 1 to 5. 9. Any one of claims 1 to 5, wherein the memory is a read-only memory in which the rotation angle of the bucket and the rotation angle of the lift arm when the bucket is in a horizontal state are stored in advance as bucket angle holding data. A bucket leveling device for a cargo handling vehicle according to item 1.