JP6156857B1 - Forklift cargo handling equipment - Google Patents

Abstract

An object of the present invention is to provide a handling device for a forklift with high operability in which lever characteristics are set regardless of button operation or switch operation. As the operation speed in the dead zone increases, the change in the command amount with respect to the change in the operation amount within a range in which the operation amount (tilt angle) in the operation zone is large among the plurality of lever characteristics (a) to (d). A lever characteristic with a larger ratio is set. As the operation speed in the dead zone is smaller, among the plurality of lever characteristics (a) to (d), a lever characteristic having a smaller change rate in a range where the operation amount in the operation band is small is set. The set lever characteristic is reset when the operating lever is returned to a predetermined reset position within the dead zone. [Selection] Figure 3

Description

  The present invention relates to a cargo handling device for a forklift for operating a cargo handling tool.

  The forklift is provided with a cargo handling device for cargo handling work. The cargo handling device includes a fork that supports a workpiece, a hydraulic drive unit that causes the fork to lift, tilt, reach, and the like, an operation lever that is operated by an operator for the operation of the fork, and the like. The hydraulic drive means includes a hydraulic circuit, a hydraulic motor, a proportional solenoid valve, a hydraulic cylinder, and the like.

  The forklift stores a lever characteristic that defines a command amount to the hydraulic drive means with respect to a tilt angle from the neutral position of the operation lever. The command amount to the hydraulic drive means is, for example, a command torque of the hydraulic motor, an exciting current of the proportional solenoid valve (amount of opening of the proportional solenoid valve), and the like. The lever characteristic has a characteristic that the command amount increases in proportion to the tilt angle, that is, a characteristic that the operating speed of the fork increases in proportion to the tilt angle. When the operation lever is operated, a command amount corresponding to the tilt angle is determined according to the set lever characteristics. The hydraulic control means is driven and controlled with the determined command amount.

  FIG. 4 shows an example of the lever characteristics stored in the forlift. As shown in FIG. 4, the forklift stores a plurality of lever characteristics (a) to (d).

  As shown in FIG. 4, within a predetermined range including the neutral position (tilt angle θ = 0), the command amount is T = 0 regardless of the tilt angle of the operation lever. That is, this range is a dead zone where the fork is not operated even when the operation lever is tilted. The range exceeding the dead zone is an operating zone in which the fork is operated when the operating lever is tilted.

  In the operation zone, in the range where the tilt angle is small as indicated by the alternate long and short dash line, the ratio of the change in the command amount with respect to the change in the tilt angle (that is, the slope of the tangent line of the characteristic curve) It is smaller than the characteristics (b) to (d). On the other hand, in the range where the tilt angle is large as indicated by the two-dot chain line, the ratio of the change in the command amount to the change in the tilt angle is greater in the lever characteristics (a) than the other lever characteristics (b) to (d). . That is, the lever characteristic (a) is easier to adjust the speed of the fork at a low speed than the other lever characteristics (b) to (d), but is difficult to adjust the speed at a high speed.

  Further, regarding the lever characteristic (d), the rate of change in the range where the tilt angle is small is larger than the other lever characteristics (a) to (c), and the rate of change in the range where the tilt angle is large is It is smaller than the other lever characteristics (a) to (c). That is, in the lever characteristic (d), it is difficult to adjust the speed of the fork at a low speed compared to the other lever characteristics (a) to (c), but it is easy to adjust the speed at a high speed.

  In order to set an appropriate lever characteristic among a plurality of lever characteristics (a) to (d) having different characteristics from each other, generally, as shown in Patent Documents 1 and 2, etc., a forklift The driver's seat buttons, switches, etc. must be operated in advance, which is troublesome for the operator.

JP 2002-274895 A JP 2014-159321 A

  The present invention provides a handling device for a forklift with high operability in which lever characteristics are set regardless of operation of buttons, switches, and the like.

The present invention includes a cargo handling tool,
An operating lever for operating the cargo handling tool;
Hydraulic drive means for operating the cargo handling equipment by hydraulic pressure when the operation lever is operated;
An operation amount detection means for detecting an operation amount from a neutral position of the operation lever;
An operation speed detecting means for detecting an operation speed of the operation lever;
The predetermined range including the neutral position of the operation lever is a dead band in which the cargo handling tool is not operated even when the operation lever is operated, and the range exceeding the dead zone is that the cargo handling tool is operated when the operation lever is operated. A forklift loading / unloading device which is an operating zone to be operated,
Characteristic storage means for storing a first lever characteristic to an nth lever characteristic in which a command amount to the hydraulic drive means with respect to the operation amount in the operation band is determined (n is a natural number of 2 or more);
In the first lever characteristic to the nth lever characteristic, the command amount increases in proportion to the operation amount,
The ratio of the change in the command amount to the change in the operation amount in the range where the operation amount is small is that the (k-1) lever characteristic is smaller than the k-th lever characteristic and the change in the range where the operation amount is large. The ratio is such that the kth lever characteristic is smaller than the (k−1) th lever characteristic (k is a natural number satisfying 2 ≦ k ≦ n),
The greater the operation speed in the dead zone, the smaller the change rate in the range in which the operation amount is large, the lever characteristic is set, the hydraulic drive means is driven and controlled according to the set lever characteristic,
The set lever characteristic is reset when the operating lever is returned from the operating zone to a reset position within the dead zone.

The present invention also includes a cargo handling tool,
An operating lever for operating the cargo handling tool;
Hydraulic drive means for operating the cargo handling equipment by hydraulic pressure when the operation lever is operated;
An operation amount detection means for detecting an operation amount from a neutral position of the operation lever;
An operation speed detecting means for detecting an operation speed of the operation lever;
The predetermined range including the neutral position of the operation lever is a dead band in which the cargo handling tool is not operated even when the operation lever is operated, and the range beyond the dead zone is the cargo handling tool when the operation lever is operated. Is a forklift cargo handling device that is an operating zone where
Characteristic storage means for storing a first lever characteristic to an nth lever characteristic in which a command amount to the hydraulic drive means with respect to the operation amount in the operation band is determined (n is a natural number of 2 or more);
In the first lever characteristic to the nth lever characteristic, the command amount increases in proportion to the operation amount,
The range of the operation amount in which the command amount is less than a predetermined value is the range of the operation amount in which the (k−1) th lever characteristic is larger than the k-th lever characteristic and the command amount is equal to or greater than the predetermined value. Is larger than the (k-1) th lever characteristic (k is a natural number satisfying 2 ≦ k ≦ n),
The greater the operation speed in the dead zone is, the larger the operation amount range in which the command amount is equal to or greater than the predetermined value is set, and the hydraulic drive means is driven and controlled according to the set lever characteristics
The set lever characteristic is reset when the operating lever is returned from the operating zone to a reset position within the dead zone.

  Preferably, the reset position is a position away from the neutral position and away from a boundary between the dead zone and the operation zone.

  Preferably, the reset position is the neutral position.

  By providing the above-described configuration, the present invention can provide a forklift cargo handling device with high operability in which lever characteristics are set regardless of button operation or switch operation.

It is a side view of a forklift provided with a material handling device of one embodiment of the present invention. It is a block diagram of the material handling apparatus of one Embodiment of this invention. The several lever characteristic of a material handling apparatus is shown. It is a figure for demonstrating a prior art.

  Referring to FIG. 1, the forklift includes a vehicle main body 1 and traveling wheels 2. The four lift includes a cargo handling device 3 for performing cargo handling work. The forklift is a reach type in the embodiment, but may be a counter balance type or the like.

  FIG. 2 shows a block diagram of the cargo handling device 3. With reference to FIGS. 1 and 2, the cargo handling apparatus 3 includes a cargo handling tool 4 for supporting a workpiece. The cargo handling tool 4 is a fork in the embodiment, but is not limited to a fork, and may be another attachment attached instead of the fork.

  The cargo handling device 3 includes an operation lever 5 that is operated by an operator for the operation of the cargo handling tool 4. The operation lever 5 is provided in the vehicle main body 1 so as to be able to tilt forward and backward from the neutral position. In the embodiment, the operation lever 5 includes a lift lever, a tilt lever, and a reach lever.

  As shown in FIG. 2, the cargo handling device 3 includes a potentiometer 6. The potentiometer 6 is provided on the base end side of the operation lever 5 so as to output high power in proportion to the tilt angle (that is, the operation amount) from the neutral position of the operation lever 5. The potentiometer 6 functions as an operation amount detection means 7 for detecting the operation amount from the neutral position of the operation lever 5 and further functions as an operation speed detection means 8 for detecting the operation speed of the operation lever 5. The tilt angle and tilt direction (operation direction) of the operation lever 5 are obtained by the voltage output from the potentiometer 6. The operation speed of the operation lever 5 is obtained by the time change of the voltage output from the potentiometer 6.

  As shown in FIG. 2, the cargo handling device 3 includes control means 9. The control means 9 is a controller. The potentiometer 6 is connected to the control means 9.

  The cargo handling device 3 includes hydraulic drive means 10 for operating the cargo handling tool 4 by hydraulic pressure when the operation lever 5 is operated. The hydraulic drive means 10 includes a hydraulic oil storage tank, a hydraulic circuit, a hydraulic cylinder, a hydraulic motor 11, and a proportional solenoid valve 12. In the embodiment, the hydraulic cylinder includes a lift cylinder, a tilt cylinder, and a reach cylinder.

  The hydraulic drive means 10 is driven and controlled by the control means 9. When the hydraulic motor 11 and the proportional solenoid valve 12 are driven, hydraulic oil is supplied to and discharged from the hydraulic cylinder, and the hydraulic cylinder expands and contracts. As a result, the cargo handling tool 4 operates. That is, in the embodiment, the fork performs a lift operation, a tilt operation, or a reach operation. For each operation of the fork, the cargo handling device 3 includes a mast 14 and a straddle leg 15 as shown in FIG. 1, but since these configurations are well known, description thereof is omitted.

  Note that the operation direction of the cargo handling implement 4 is determined by the tilting direction of the operation lever 5 detected by the operation amount detection means 7. In the embodiment, the movement direction of the cargo handling device 4 is lift-up or lift-down, forward tilt or rear tilt, or reach-in or reach-out.

  The control means 9 determines the command amount based on the tilt angle detected by the operation amount detection means 7 in accordance with the relationship of the command amount to the hydraulic drive means 10 with respect to the tilt angle shown in FIG. The hydraulic drive means 10 is driven and controlled by the amount. Here, the command amount is a command torque of the hydraulic motor 11 and is an exciting current of the proportional solenoid valve 12 (which determines an opening amount of the proportional solenoid valve 12). That is, when the command amount increases, the operation speed of the cargo handling tool 4 increases.

  In FIG. 3, the horizontal axis is the tilt angle of the operation lever 5, and the origin is the neutral position (θ = 0). An increase in tilt angle from the neutral position to the right means forward tilt of the operation lever 5, and an increase in tilt angle from the neutral position to the left means backward tilt of the operation lever 5. The vertical axis is the command amount. Note that the relationship of the command amount with respect to the tilt angle is the same for the forward tilt and the rear tilt.

Even if the operation lever 5 is operated within a predetermined range including the neutral position, the control means 9 sets the command amount to T = 0 regardless of the tilt angle, and does not operate the cargo handling equipment 4. Accordingly, a predetermined range including the neutral position (0 ≦ θ ≦ θ ₁ ) becomes a dead zone where the cargo handling tool 4 is not operated even when the operation lever 5 is operated.

When the operation lever 5 is operated beyond the dead zone, the control means 9 controls the hydraulic drive means 10 according to the tilt angle of the operation lever 5 to operate the cargo handling equipment 4. As a result, the range up to the maximum tilt angle exceeding the dead zone (θ ₁ <θ ≦ θ _max ) is an operation zone in which the cargo handling tool 4 is operated when the operation lever 5 is operated.

  In order to determine the command amount based on the tilt angle detected by the operation amount detection means 7, the cargo handling device 3 stores the first lever characteristic or n-th lever characteristic in which the command amount for the tilt angle is determined. Means 13 (FIG. 2) is provided (where n is a natural number of 2 or more). In the embodiment, n = 4, and as shown in FIG. 3, the first lever characteristic (a), the second lever characteristic (b), the third lever characteristic (c), and the fourth lever characteristic (d) are characteristic storage means. 13 is stored.

Each of the lever characteristics (a) to (d) in FIG. 3 has the following characteristics when the tilt angle is θ ₁ <θ <θ _{2 in} the operation band.
In the lever characteristics (a) to (d), the command amount increases continuously to a command amount T = T _max of 100% in proportion to the tilt angle. The command amount is larger in the k-th lever characteristic than in the (k−1) -th lever characteristic at an arbitrary tilt angle (however, a natural number satisfying 2 ≦ k ≦ 4). In the range where the tilt angle is small, the ratio of the change in the command amount to the change in the tilt angle (that is, the slope of the tangent to the characteristic curve) is smaller in the (k−1) th lever characteristic than in the kth lever characteristic. On the other hand, in the range where the tilt angle is large, the ratio of the change in the command amount to the change in the tilt angle is smaller in the k-th lever characteristic than in the (k−1) -th lever characteristic.

Thus, the tilt angle θ1 <θ <θ2, the reference variable is the low speed range a range of tilt angle is less than a predetermined value (T = T _A), and high-speed band range of tilt angle is equal to or greater than the predetermined value T _A Then, in the low speed band, the (k−1) th lever characteristic is larger than the kth lever characteristic, and in the high speed band, the kth lever characteristic is larger than the (k−1) lever characteristic.

  That is, the (k−1) th lever characteristic is easier to adjust the speed when the cargo handling tool 4 is operated at a lower speed than the kth lever characteristic, but it is difficult to adjust the speed when the cargo handling tool 4 is operated at a high speed. The k-th lever characteristic is more difficult to adjust the speed when operating the cargo handling tool 4 at a lower speed than the (k-1) -th lever characteristic, but it is easier to adjust the speed when operating the high-speed operation.

In the range of θ ₂ ≦ θ ≦ θ _max , the command amount of each lever characteristic (a) to (d) is T _max and constant.

Hereinafter, setting and resetting of the lever characteristics by the control means 9 and control of the hydraulic drive means 10 when the operator operates the operation lever 5 from the neutral position to the operation band will be described.
When the operating lever 5 is operated from the neutral position to the operating zone by the operator to the operating zone, the control means 9 uses the operating amount detecting means 7 and the operating speed detecting means 8 to set the operating speed V _c of the operating lever 5 in the dead zone. get. The operating speed V _c may be an average speed at which the operating lever 5 to move the dead zone, may be a maximum speed of the speed detected when moving the dead zone, the predetermined detection position in the dead zone It is good also as speed when passing.

Next, the control means 9 sets the lever characteristic in the operation band from the first lever characteristic (a) to the fourth lever characteristic (d) based on the operation speed V _c in the dead band. Specifically, the control means 9 sets a lever characteristic having a smaller change rate in a range where the tilt angle is larger, that is, a lever characteristic having a larger high speed band, as the operation speed V _c in the dead zone is larger.

More specifically, the control means 9 sets the first lever characteristic (a) when 0 <V _c ≦ V ₁ , and the second lever characteristic (b) when V ₁ <V _c ≦ V _2. The third lever characteristic (c) is set when V ₂ <V _c ≦ V ₃ , and the fourth lever characteristic (d) is set when V ₃ <V _c .

  The control means 9 determines the command amount from the tilt angle detected by the operation amount detection means 7 in accordance with the lever characteristics set as described above while the operation lever 5 is operated in the operation band. Then, the control means 9 drives and controls the hydraulic drive means 10 (that is, the hydraulic motor 11 and the proportional electromagnetic valve 12) with the determined command amount, thereby operating the cargo handling tool 4.

The control means 9 drives and controls the hydraulic drive means 10 according to the set lever characteristics until the operation lever 5 operated in the operation band is returned to the predetermined reset position in the dead band. On the other hand, when the control means 9 detects that the operation lever 5 has been returned to the reset position based on the tilt angle by the operation amount detection means 7, the control means 9 resets the set lever characteristics. The control unit 9, after the reset of the lever characteristics, when the operation lever 5 is operated to again operating band beyond the dead zone, as described above, based on the operating speed V _c of the dead zone is detected by the operation speed detector 8 Set the lever characteristics to.

In cargo handling device 3 according to the present invention as described above, based on the operating speed V _c of the operation lever 5 in the dead zone, the lever characteristics in operating band is automatically set. Therefore, it is not necessary for the operator to manually set or switch the lever characteristics before operating the cargo handling tool 4.

  When the operator operates the operation lever 5 slowly, among the plurality of lever characteristics (a) to (d), in the range where the operation amount (tilt angle) is small, the change rate of the command amount with respect to the change in the operation amount is small, and the low speed band A lever characteristic with a large is set. When the operator wants to operate the cargo handling device 4 at a low speed, the operator operates the operation lever 5 slowly. In such a case, the first lever characteristic (a) or the second lever characteristic (b), The lever characteristic that makes the speed adjustment of the cargo handling device 4 at a low speed relatively easy is automatically set.

  When the operator operates the operating lever 5 vigorously, among the plurality of lever characteristics (a) to (d), a lever characteristic is set in which the rate of change is small and the high speed band is large in a range where the operation amount is large. When the operator wants to operate the cargo handling device 4 at a high speed, he / she operates the operating lever 5 vigorously. In such a case, as in the fourth lever characteristic (d) and the third lever characteristic (c). The lever characteristic that makes the speed adjustment of the cargo handling device 4 at a high speed relatively easy is automatically set.

  Further, the set lever characteristic is maintained until the operation lever 5 is returned to the reset position after the lever characteristic is set once, and the hydraulic drive means 10 is driven and controlled in accordance therewith. When the operation lever 5 is returned to the reset position, the set lever characteristics are reset.

  That is, according to the cargo handling device 3 according to the present invention, each time the operator operates the operation lever 5, a lever characteristic suitable for the operation is automatically selected from the plurality of lever characteristics (a) to (d). The operability is very good.

  The reset position is set within the dead zone, but is preferably located at a position away from the neutral position and away from the boundary between the dead zone and the operation zone (θ = θ1).

  The operator may operate the operation lever 5 again to the operation zone without completely returning the operation lever 5 to the neutral position. By setting the reset position to a position away from the neutral position, the lever characteristic suitable for the next operation is automatically set even in such a case. Of course, the reset position may be set to the neutral position.

  In order to adjust the position of the cargo handling tool 4, the operator may finely operate the operation lever 5 within a small tilt angle within the operation band. At this time, the operation lever 5 is slightly moved from the operation band to the dead band. May end up. By setting the neutral position to a position away from the boundary between the dead zone and the operation zone to some extent, the setting of the lever characteristics is maintained without being reset even in such a case, and the operator continues to adjust the position of the cargo handling device 4. be able to.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the said embodiment. In the above embodiment, as shown in FIG. 3, the relationship of the command amount with respect to the tilt angle (operation amount) is the same between the forward tilt and the rear tilt, but may be different between the forward tilt and the rear tilt. In addition, the relationship between the command amount and the operation amount is not limited to the example illustrated in FIG. Further, in the above embodiment, four lever characteristics are provided in advance, but two lever characteristics, three lever characteristics, or five or more lever characteristics may be provided in advance.

DESCRIPTION OF SYMBOLS 1 Vehicle main body 2 Wheel 3 Handling apparatus 4 Handling tool 5 Operation lever 6 Potentiometer 7 Operation amount detection means 8 Operation speed detection means 9 Control means 10 Hydraulic drive means 11 Hydraulic motor 12 Proportional solenoid valve 13 Characteristic storage means 14 Mast 15 Straddle leg ( a) First lever characteristic (b) Second lever characteristic (c) Third lever characteristic (d) Fourth lever characteristic

Claims (4)

Cargo handling equipment,
An operating lever for operating the cargo handling tool;
Hydraulic drive means for operating the cargo handling equipment by hydraulic pressure when the operation lever is operated;
An operation amount detection means for detecting an operation amount from a neutral position of the operation lever;
An operation speed detecting means for detecting an operation speed of the operation lever;
The predetermined range including the neutral position of the operation lever is a dead band in which the cargo handling tool is not operated even when the operation lever is operated, and the range exceeding the dead zone is that the cargo handling tool is operated when the operation lever is operated. A forklift loading / unloading device which is an operating zone to be operated,
Characteristic storage means for storing a first lever characteristic to an nth lever characteristic in which a command amount to the hydraulic drive means with respect to the operation amount in the operation band is determined (n is a natural number of 2 or more);
In the first lever characteristic to the nth lever characteristic, the command amount increases in proportion to the operation amount,
The ratio of the change in the command amount to the change in the operation amount in the range where the operation amount is small is that the (k-1) lever characteristic is smaller than the k-th lever characteristic and the change in the range where the operation amount is large. The ratio is such that the kth lever characteristic is smaller than the (k−1) th lever characteristic (k is a natural number satisfying 2 ≦ k ≦ n),
The greater the operation speed in the dead zone, the smaller the change rate in the range in which the operation amount is large, the lever characteristic is set, the hydraulic drive means is driven and controlled according to the set lever characteristic,
The set lever characteristic is reset when the operation lever is returned from the operation zone to a reset position within the dead zone.
A forklift cargo handling device characterized in that. Cargo handling equipment,
An operating lever for operating the cargo handling tool;
Hydraulic drive means for operating the cargo handling equipment by hydraulic pressure when the operation lever is operated;
An operation amount detection means for detecting an operation amount from a neutral position of the operation lever;
An operation speed detecting means for detecting an operation speed of the operation lever;
The predetermined range including the neutral position of the operation lever is a dead band in which the cargo handling tool is not operated even when the operation lever is operated, and the range beyond the dead zone is the cargo handling tool when the operation lever is operated. Is a forklift cargo handling device that is an operating zone where
Characteristic storage means for storing a first lever characteristic to an nth lever characteristic in which a command amount to the hydraulic drive means with respect to the operation amount in the operation band is determined (n is a natural number of 2 or more);
In the first lever characteristic to the nth lever characteristic, the command amount increases in proportion to the operation amount,
The range of the operation amount in which the command amount is less than a predetermined value is the range of the operation amount in which the (k−1) th lever characteristic is larger than the k-th lever characteristic and the command amount is equal to or greater than the predetermined value. Is larger than the (k-1) th lever characteristic (k is a natural number satisfying 2 ≦ k ≦ n),
The greater the operation speed in the dead zone is, the larger the operation amount range in which the command amount is equal to or greater than the predetermined value is set, and the hydraulic drive means is driven and controlled according to the set lever characteristics
The set lever characteristic is reset when the operation lever is returned from the operation zone to a reset position within the dead zone.
A forklift cargo handling device characterized in that.   The forklift handling device according to claim 1 or 2, wherein the reset position is a position away from the neutral position and away from a boundary between the dead zone and the operation zone.   The forklift loading / unloading apparatus according to claim 1, wherein the reset position is the neutral position.

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