JPS61106834A - Bucket levelling device for loading and unloading vehicle - Google Patents

Abstract

PURPOSE:To simplify levelling of a bucket, by a method wherein, during the control of a damp cylinder, a control signal is outputted to a control valve in priority thereof to or addition of a correction control signal. CONSTITUTION:By means of 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. The two angles are compared with bucket angle holding data in memories 18 and 28 to compute a correction control signal required for levelling of the bucket. During control of a control pedal 15 of a damp cylinder 9, the output of a control signal for a pedal 15 is outputted to a control valve 19 of a damp cylinder 9 in priority of the control signal to a correction control signal, or the signal for the pedal 15 added to the correction control signal is outputted thereto.

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 at both ends between the support plate portion 32 and the bracket 36, and the lift arm 33° leveling link 38. Bracket 36. A parallel link was configured from the support plate portion 32. And lift cylinder 3
4 is activated, 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, since the bracket 36 and the leveling link 38 must be provided as described above, there is a problem in that there are significant restrictions in terms of design layout and strength, and
It is troublesome to assemble and also increases the weight of the entire vehicle.

Furthermore, some vehicles are not provided with the leveling link 38, but in these types of vehicles, the operator must always control the attitude of the bucket 35 when raising or lowering the lift arm 33. There was a problem in that the work had to be done while doing so, making the work very troublesome and complicated.

Structure of the Invention (Means for Solving the Problems) The present invention solves the above problems. The bucket leveling device of the present invention is provided with a lift arm that is raised and lowered by a lift cylinder on the vehicle body frame, reach arm, etc., and the tip of the lift arm is rotated up and down by a dump cylinder. a dump cylinder operating means for operating the dump cylinder; a lift cylinder operating means for mechanically driving and operating a control valve for the lift cylinder for operating the lift cylinder;
A lift arm movement sensor that detects the movement amount of the lift arm, a bucket movement sensor that detects the movement amount of the bucket, a memory that stores bucket angle holding data, and a lift arm movement sensor that detects the movement amount of the bucket. The first step inputs the detected detection signal and the detection signal detected by the bucket movement amount sensor from time to time, and calculates the angle of the lift arm and the angle of the bucket based on each detection signal.
and a dump cylinder necessary for leveling the bucket corresponding to the rotation angle of the lift arm at that time by comparing both angles calculated by the first calculation means and the bucket angle holding data in the memory. and a second calculation means for calculating the operation amount of . The gist thereof is that it is comprised of a drive control means for preferentially or allowing the 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; .

(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 the amount of operation of the dump cylinder required for leveling the bucket corresponding to the rotation angle of the lift arm at that time. Calculate.

When the dump cylinder operating means is operated, the 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 calculated by the second calculation means, or when the dump cylinder operating means is operated. A signal obtained by adding the operation signal of the 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 control valve of the lift cylinder is mechanically operated by operating the lift cylinder operating means.

(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. 1, and a bucket 7 is rotatably supported at the tip on both sides of the rear end. There is. ., i bent portion 1 of the lift arm 5. :
The base end of the dump cylinder 9 is rotatably supported on the 8104 and 8104 points 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 0 as a lift arm movement sensor is provided at the base end of the lift arm 5, and the arm angle sensor 0 detects the movement amount, that is, the rotation angle of the lift arm 5. A bucket angle sensor 1 as a bucket movement 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 4 consists of a potentiometer, and the dump pedal 15 serves as a dump cylinder operating means.
Detects the amount of depression. The lift pedal opening sensor 6 also includes a potentiometer, and 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.

The central processing unit (hereinafter referred to as CPU) as the first calculation means, second calculation means, and drive control means is in the ROM28.
Each arm angle sensor 10. is driven based on a control program stored in the arm angle sensor 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 rotation angle of the lift arm 5 and the bucket 7 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, at the time when the bucket 7 has finished rotating by the dump cylinder 9). A memory 18 (hereinafter referred to as RAM) that can read and replace the rotation angles of the lift arm 5 and bucket 7 at that time as bucket angle holding data.
Store in.

In addition, the lift pedal 1 as a lift cylinder operating means
7 mechanically controls the control valve 20 via a hydraulic mechanism when the lift pedal 17 is depressed;
It is adapted to drive the lift cylinder 6.

Further, the CPU 13 determines whether the lift pedal 17 is depressed or not, and inputs the start command signal of the lift pedal opening sensor 16. When the CPU 13 determines that the lift pedal 17 is depressed, the CPU 13 It is determined whether the dump pedal 15 is depressed. When the dump pedal is determined to be depressed, the CPU 13
resets the angle holding data, calculates the dump cylinder operation distance according to the depression amount of the dump pedal 15, and sends an operation signal proportional to the dump pedal opening amount at that time to the control valve 19 of the dump cylinder 9 via the interface 12. It is designed to be output via . The control 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 CPU 13 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.

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, the dump pedal is operated according to the amount of depression of the dump pedal. The 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 described in 1.A above 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 depression amount of the dump 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 1.2.

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

At this time, the CPU 13 calculates the rotation m, that is, the rotation angle, of the lifted arm 5 and the bucket 7 based on the rain detection signals from the arm angle sensor 1o and the bucket angle sensor 11 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 bucket angle sensor 10 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. 1, when only the lift pedal 17 is depressed to rotate the lift arm 5 upward, the control valve 20 is mechanically controlled via the hydraulic mechanism. The lift cylinder 6 is driven to rotate the lift arm 5 upward.

When this lift pedal 17 is depressed and operated, the CPU
13 determines that the lift pedal 17 is being depressed based on the start command signal of the lift pedal opening sensor 16, and then determines whether or not the dump pedal 15 is being depressed. Then, when it determines that the dump pedal is depressed, the CPU
i 3 resets the angle holding data and dump pedal 1
Calculate the amount of dump cylinder operation according to the amount of depression in step 5,
An operation signal proportional to the amount of the dump pedal opening 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.

On the other hand, when the CPU 13 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.

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, the dump pedal is operated according to the amount of depression of the dump pedal. The cylinder operation amount is calculated, and an operation signal proportional to the dump pedal opening amount at that time is outputted to one control valve 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 CPLJ 13.
'li to control.

Note that in order to return from the state shown in FIG. 2 to the state shown in FIG. It moves downward together with the lift arm 5 while maintaining that posture.

In this way, unlike the conventional method, a parallel link is not used, and the operator does not control the attitude of the bucket 7 himself, so there is no need to operate the foot arm 5, and the bucket 7 can be easily leveled.

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, calculates the depression amount of the dump pedal 15 with priority, and outputs an operation signal proportional to the dump pedal opening amount at that time to the control valve 19 of the dump cylinder 9. CPU
13 adds an operation signal proportional to the amount of dump pedal opening at that time to the correction control signal to control the dump cylinder 9.
The configuration is such that the output is output to the control valve 19 of.

In the first embodiment, the leveling start command means is the lift pedal 17, but the lift pedal angle sensor 1
6 is omitted and no leveling start command means is provided, and the CPU 13 constantly inputs the detection signals from the arm angle sensor 1o and the bucket angle sensor 11, and adjusts the rotation angle of the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time. The operation amount of the dump cylinder 9 necessary for leveling is calculated in the same manner as in the first embodiment, 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. do.

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 travel date of the stroke of the dump cylinder 9 is placed close to the dump cylinder 9 as a bucket movement amount sensor. There is.

Therefore, in this second embodiment, the CPU 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 lift cylinder stroke sensor 21 and the dump cylinder stroke sensor 22.

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 that is mechanically driven and operated by the dump pedal 15 or a main control valve 23 that inputs a detection signal detected by the dump pedal opening sensor 4 of the dump pedal 15. and a sub-control valve 24 which inputs a correction control signal from the CPU 13, and is connected to the main control valve 23 and the sub-control valve 24, and a switching signal output from the CPU 13,
The switching valve 25 selectively connects the main control valve 23 or the auxiliary control valve 24 to the dump cylinder 9.

Further, when the dump pedal 15 is depressed, the CPU 13 inputs a detection signal from the dump pedal opening sensor 4, and sends a switching signal to the switching valve 25 to switch the switching valve 25 to the main control valve 23 side based on the detection signal. Output for. Also, the dump pedal 15 of the CPU 13 is depressed! When not being operated, a switching signal is output to the switching valve 25 to switch the switching valve 25 to the sub-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. The bucket angle holding data is compared with the bucket angle holding data, the operation amount of the dump cylinder 9 necessary for leveling the bucket corresponding to the rotation angle of the lift arm 5 at that time is calculated, and a correction control signal based on the operation amount is sent to the interface. 1
Secondary control valve 2 of dump cylinder 9 via 2
Output to 4. The difference from the first embodiment is that the 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 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.
Switch to side 3. Then, the dump cylinder 9 is controlled and driven based on the detection signal from the dump pedal opening sensor 14.

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

Note that other functions are similar to those of the first embodiment.

In this embodiment, the configuration in which the dump cylinder 9 is connected to the dump pedal 15 via the main control valve 23 is a conventional configuration.

Therefore, compared to the conventional system, the secondary control valve 2
4. By simply adding the switching valve 25 and the CPU 13, RAM 18, etc. as the calculation means 2 for the first calculation means and the drive control means, the bucket 7 can be operated without using a parallel link.
can be leveled.

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. may be configured.

That is, when the dump pedal 15 is depressed, the CP (J13) inputs the detection signal from the dump pedal opening sensor 14, and switches the switching valve 2 based on the detection signal.
5 to the confluence side with the main control valve i3 and the sub control valve 24.
It is designed to output to. Further, when the dump pedal 15 is not depressed, 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.

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.

Other operations are similar to those of the third embodiment.

Furthermore, FIGS. 10 and 11 regarding a modification of the third embodiment.
This will be explained according to the diagram.

In this modification, in the configuration of the third embodiment, the switching valve 2
5 is omitted, 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 control valve 20 is mechanically driven.

At this time, the CPU 13 stores 1'□<
7. Care, read the angle holding data, and then (7)
ffll: Reads the input detection signals from the arm angle sensor 10 and bucket angle sensor 11, and compares the rotation angles of the lift arm 5 and bucket 7 at each time based on the detection signals with the bucket angle holding data. Then, 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, and a correction control signal based on the operation ω is sent to the dump cylinder 9 via the interface 12. It is designed to output to the sub control valve 24 of.

Further, the CPtJ13 calculates a dance cylinder operation amount according to the dump pedal depression position, and outputs an operation signal based on the operation amount to the main control valve.

Therefore, in this embodiment, the control valve 20 moves the lift cylinder 6 based on the depression operation of the lift pedal 17 so that the bucket 7 rotates the lift arm 5 upward, and the lift arm 5 is rotated upward. make it move.

At this time, the CPU 13 reads the bucket angle holding data stored in the RAM 18 based on the signal from the lift pedal opening sensor 16, reads 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 each time based on the detection signal is compared with the bucket angle holding data, and the leveling of the bucket 7 corresponding to the rotation angle of the lift arm 5 at that time is performed. The operating amount of the dump cylinder 9 is calculated, and a correction control signal based on the operating amount is output to the sub control valve 24 of the dump cylinder 9 via the interface 12.

Further, the CPIJ 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 pulse 723.

Then, the dump cylinder 9 is driven by both the main control valve 23 and the sub control valve 24.

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, 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 in the ROM 28 in the configuration of the first embodiment as bucket angle holding data. What they do is different.

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 to the floating state, the bucket 7 is moved to the state shown in FIGS. 12 to 13 so as to maintain the horizontal state as the lift arm 5 moves downward. Leveling will then take place.

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, CPt
A ROM 26 is provided for J13, and the ROM 26 stores in advance 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 as bucket angle holding data. Also, a lift pedal 17 for instructing the first embodiment to start bucket leveling.
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 as a first start command means.

Then, 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. The push button switch 27, which is the second start command means, is turned to O.
When N is selected, the dump cylinder 1 is controlled and driven by the dump cylinder 9 so as to maintain the bucket 7 in a horizontal state. '1'4 Other operations are the same as 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.

Note that the present invention is not limited to the above-mentioned embodiments; for example, in the configuration of the second to fourth embodiments, the leveling start command means is the lift pedal 17, but the lift pedal angle sensor 16 is omitted. The CPU 13 constantly inputs the detection signals from the arm angle sensor 10 and the bucket angle sensor 11 without providing a leveling start command means,
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 way as in the first embodiment, and a correction control signal based on the operation amount is sent to the interface 12. It may be configured such that the output is outputted to the control valve 19 of the dump cylinder 9 via the control valve 19 of the dump cylinder 9.

Effects of the Invention As detailed above, since this invention does not use parallel links for leveling the bucket, constraints in terms of design layout and strength are eliminated, assembly is not troublesome unlike conventional methods, and it is easy to use in vehicles. This invention is suitable for industrial use because it has the effect of reducing the weight of the bucket and making it easy to level the bucket.

[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 flowchart of a modification of the first embodiment, and FIG. 6 is a side view of the cargo handling vehicle of the second embodiment. Figure 7 is the same electric block circuit diagram, Figure 8 is the electric block circuit diagram of the third embodiment, and Figure 9 is the same central processing unit (
A flowchart for explaining the processing operation of the CPU,
Fig. 10 is an electric block circuit diagram showing a modification of the third embodiment, Fig. 11 is a flowchart as well, Fig. 12 is a side view of the cargo handling vehicle of the fourth embodiment when the lift arm is raised, and Fig. 13 The figure is a side view when the lift arm is moved upward from the state shown in Fig. 12, Fig. 14 is an electrical block circuit diagram, and Fig. 15
The figure is an electric block circuit diagram of the fifth embodiment, FIG. 16 is a flowchart for explaining the processing operation of the central processing unit (CPU), and FIG. 17 is a side view of a conventional cargo handling vehicle. 1 is a vehicle body frame, 2 is a front wheel, 3 is a rear wheel, 4 is a support plate, 5 is a lift arm, 6 is a lift cylinder, 7 is a bucket, 8 is a bracket, 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 unit (CPU), 14
is the dump pedal opening sensor, 15 is the dump pedal, 16
is the lift pedal opening sensor, 17 is the lift pedal, 18
RAM119 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 a ROM
, 31 is a vehicle body frame, 32 is a support plate, 33 is a lift arm, 34 is a foot cylinder, 35 is a bucket, 37
is a dump cylinder, and 38 is a leveling link. Patent applicant Toyota Automatic Machinery Co., Ltd. Representative
Person Patent Attorney On 1) Hironobu'/a'/ Figure 5 Figure 15 Figure 16

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 mechanically driving and operating a control valve for the lift cylinder for operating the lift cylinder; and detecting the amount of movement of the lift arm. A lift arm movement sensor, a bucket movement sensor that detects the movement of the bucket, a memory that stores bucket angle holding data, and a detection signal detected by the lift arm movement sensor from time to time and a bucket movement sensor from time to time. a first calculation means that inputs the detection signal detected by the quantity sensor and calculates the angle of the lift arm and the angle of the bucket based on each detection signal; both angles calculated by the first calculation means and 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 at that time by comparing the bucket angle holding data in the table; Sometimes, the output of the operation signal of the dump cylinder operation means is given priority over the correction control signal based on the operation amount calculated by the second calculation means, or the operation signal of the dump cylinder operation means is added to the correction control signal. A bucket leveling device for a cargo handling vehicle, comprising: a drive control means for outputting a signal to a control valve section of a dump cylinder; and a bucket leveling device for a cargo handling vehicle. 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 the operation signal from the dump cylinder operating means, a sub-control valve that inputs the correction control signal from the drive control means, and the main control valve and the sub-control. A switch that is connected to the valve and switches to the main control valve when the dump cylinder operating means is operated in response to a switching signal from the drive control means, 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, which comprises a valve. 7. The control valve section of the dump cylinder includes a main control valve that inputs the operation signal from the dump cylinder operation means, and a signal that inputs the sum of the operation signal of the dump cylinder operation means and the correction control signal from the drive control means. a sub-control valve connected to the main control valve and the sub-control valve, which switches to the merging side of the main control valve and the sub-control valve when the dump cylinder operating means is operated by a switching signal from the drive control means; 2. The bucket leveling device for a cargo handling vehicle according to claim 1, further comprising a switching valve that switches to an auxiliary control valve when the dump cylinder operating means is not operated. 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.