JPH11292498A - Picking fork lift truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect that a driver's section is at a specified height level in a picking fork lift truck whose fork and driver's section are both constituted so as to be movable up and down independently, and in which a cargo placing section is formed integrally with the driver's section. SOLUTION: A functioning parts chamber 8 is provided at the rear part of a base 2. At an upper end of a support 7a erected at the rear part of a driver's section 7, a cargo placing section 28 is fixed in a face-to-face relation with the chamber 8. The driver's section 7 is supported so as to be movable up and down along masts 5, and operated up and down by a lift cylinder for the driver's section 7. On the outer surface of one of the masts 5, a plurality of detected parts 30 are formed along the longitudinal direction thereof at a specified pitch. At the front part of the driver's section 7, a sensor for detecting the parts 30 are mounted. According to the detection signal outputted from the sensor, the height level of driver's section 7 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picking forklift, and more particularly to a picking forklift, in which both a fork and a driver's seat can be independently raised and lowered, and a luggage storage which is lifted and lowered integrally with a driver's seat behind the driver's seat. The present invention relates to a picking forklift in which a part is formed.

[0002]

2. Description of the Related Art Conventionally, a cargo handling operation by raising and lowering a fork, and a picking operation in which a driver moves up and down together with a driver seat configured to be able to move up and down to move a load between a shelf at a high position and a forklift. There are possible picking forklifts. Japanese Patent Application Laid-Open No. 5-229787 discloses a picking forklift of this type.
A fork is provided at the front of the machine base, and a driver's seat is provided at the rear of the machine base. The fork and the driver's seat are configured to be able to move up and down independently by corresponding mast devices. In this picking forklift, a luggage storage unit is provided in front of a driver's seat. However, since various operation levers and a steering for steering the vehicle are provided on the front side of the driver's seat, it is difficult to secure a wide luggage compartment.

Therefore, the applicant of the present application has disclosed that both the fork and the driver's seat can be lifted and lowered independently of the machine stand, and the fork is provided at the front of the machine stand, and the function is provided at the rear of the machine stand. A picking forklift with a parts room was proposed. In this picking forklift, a luggage storage unit that moves up and down integrally with the driver's seat is provided behind the driver's seat. Therefore, in this picking forklift, the width of the luggage storage portion can be provided to be the full width of the vehicle, and a wide luggage storage portion can be secured.

[0004]

A picking forklift having a functional component room provided at the rear of the machine base is provided at the rear of the driver's seat when the driver's seat is disposed at the lowest position, and the picking forklift is provided with the driver's seat. The luggage storage unit that moves up and down integrally is in a state where there is a slight gap above the functional component room. But,
When the driver's seat rises, a large space is created above the functional parts room. And since the upper part of a functional parts room is flat, there is a possibility that an operator other than a driver may erroneously temporarily place a load on the upper part of the functional parts room. If the driver's seat descends to the lowermost position in this state, there is a possibility that the luggage placed on the upper side of the functional component room is crushed by the luggage storage unit and is damaged.

[0005] As a means for solving the above-mentioned inconvenience, it is conceivable to call attention to whether or not there is luggage above the functional parts room before the driver lowers the driver's seat.
As a method of calling attention, it is conceivable that the driver does not allow the driver's seat to descend even though the driver performs the descending operation consciously of descending. In such a case, it is useless to regulate the descent in a state where there is no possibility that the luggage is erroneously placed between the upper part of the functional component room and the luggage storage section. There is a need to. However, conventional picking forklifts are not equipped with a means for detecting the height of the driver's seat.

[0006] The position suitable for the picking operation is determined by the height of the shelf on which the picking operation is performed. Since the height of the shelf on which the picking operation is performed is usually constant, the position suitable for the picking operation is also constant. However, in a conventional picking forklift, the driver operates the driver's seat elevating lever to visually determine the driver's seat so as to be in a position suitable for the picking operation, and raises and lowers the driver's seat. In this case as well, if there is a means for detecting that the driver's seat has reached a predetermined height, it can be confirmed that the driver's seat has reached an appropriate position based on the detection signal,
Easy lifting operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object both a fork and a driver's seat which can be independently raised and lowered, and a driver's seat behind the driver's seat. It is an object of the present invention to provide a picking forklift in which a luggage storage unit that moves up and down integrally is formed and that can detect that a driver's seat is at a predetermined height.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, both the fork and the driver's seat can be independently raised and lowered with respect to the machine base. A picking forklift in which a fork is provided at a front portion of a machine base, and a luggage storage portion which moves up and down integrally with a driver's seat is formed at a rear portion of the driver's seat, wherein a lift detecting means for detecting the height of the driver's seat With.

[0009] In the invention described in claim 2, the lift detecting means is configured to be able to detect that the driver's seat is arranged at a plurality of predetermined locations. According to a third aspect of the present invention, in the first aspect of the present invention, the height detecting means is configured to be able to continuously detect the height of the driver's seat.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the lift detecting means is provided on a mast for guiding the elevation of the driver's seat at a predetermined pitch along a longitudinal direction thereof. A detection unit; and a sensor that moves together with the driver's seat and detects the detection target.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the picking forklift further operates the lift cylinder for a driver seat for raising and lowering the driver seat. A control valve for controlling oil supply and discharge, a driver's seat elevating operation member for operating the control valve, and a bottom chamber of the driver's seat lift cylinder in a state where the driver's seat elevating operation member is operated to a lowered position. An electromagnetic valve provided in a return line of a hydraulic circuit communicating with an oil tank, and always opening the electromagnetic valve, and raising the height of the driver's seat based on a detection signal from the height detecting means. When the driver's seat elevating operation member is disposed at the lowering position in a state where the height is equal to or lower than a predetermined height, and when the predetermined lifting height is reached during the descent from a position higher than the predetermined height. Close valve And control means for the state.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the control unit is configured to control the descent even when the detection signal indicating the predetermined height is output from the height detection unit. The solenoid valve is opened again based on the re-lowering operation of the restart means.

Therefore, according to the first aspect of the present invention, when the driver's seat is moved up and down with respect to the machine stand, the luggage storage unit supported by the support provided at the rear of the driver's seat moves up and down together with the driver's seat. . The height of the driver's seat is detected by the height detection means. The detection signal of the height detecting means can be used for the control of raising and lowering the driver's seat.

According to a second aspect of the present invention, in the first aspect of the invention, a detection signal is output from the lift detecting means each time a driver's seat is arranged at a plurality of predetermined locations. According to a third aspect of the present invention, in the first aspect of the present invention, the elevation is continuously detected from the elevation detection means in response to the elevation of the driver's seat. The term “continuous” is not limited to perfect continuity, but also includes a case where detection is performed at a predetermined pitch interval (for example, 1 cm interval).

According to a fourth aspect of the present invention, in the third aspect of the present invention, the lift detecting means is a detected portion formed at a predetermined pitch along a longitudinal direction of a mast for guiding the driver's seat up and down. Is output each time the sensor detects. The sensor is moved integrally with the driver's seat, and the detected portion at a position corresponding to each lift is sequentially detected by the sensor.

According to a fifth aspect of the present invention, in accordance with the first aspect of the present invention, the operation of the driver's seat elevating operation member causes the operation of the driver's seat lift cylinder to the driver's seat lift cylinder. The supply and discharge of hydraulic oil is controlled. The solenoid valve provided in the return line of the hydraulic circuit that connects the bottom chamber of the driver's seat lift cylinder to the oil tank is always kept open. When the driver's seat elevating operation member is disposed at the lowered position in a state where the driver's seat height is equal to or lower than a predetermined height, the solenoid valve is activated by a command from the control means based on a detection signal of the height detection means. It can be switched to the closed state. Also,
When the driver's seat reaches the predetermined height while descending from a position higher than the predetermined height, the solenoid valve is switched to the closed state by a command from the control means based on a detection signal of the height detection means. Therefore, although the driver performs each operation, the lowering of the driver's seat is regulated, so that the driver's attention is drawn.

According to a sixth aspect of the present invention, in the invention of the fifth aspect, the descent resuming means is operated again in a state where the predetermined lift is detected and the solenoid valve is kept closed. Then, the solenoid valve is switched to the open state again by the control means, and the driver's seat starts lowering.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 and 2, the machine base 2 of the picking forklift 1 includes two front wheels 3 and one rear wheel 4. A pair of left and right masts 5 are provided upright at the front of the machine base 2, and the masts 5 are provided with a fork 6 and a driver's seat 7, respectively, which can be moved up and down independently. A functional component room 8 is provided at the rear of the machine base 2. Functional parts room 8
A drive unit for driving the rear wheel 4 and a battery (both not shown) are accommodated therein.

As shown in FIG. 3, in the pair of left and right masts 5, grooves 5a are formed along the longitudinal direction of the mast 5 on the inner surfaces (opposing surfaces) of the masts 5, respectively. A convex ridge 5b is formed along the longitudinal direction of the mast 5. The two masts 5 are interconnected by a beam 9 fixed to the rear end face of each mast 5. Beam 9
A forklift cylinder 10 is provided in front of the
On the rear side, the driver's seat lift cylinders 11 are arranged in a state of being arranged in the front-rear direction.

The lift bracket 12 to which the fork 6 is fixed is attached to a pair of left and right arms 13 projecting from the rear portion thereof.
A bearing 14 that rolls in the groove 5a is provided. A chain pulley 15 is attached to a tip of a piston rod of the fork lift cylinder 10. The first end of the chain pulley 15 is the lift bracket 1
2, a chain 16 having a second end connected to the beam 9 is wound. The lift bracket 12 moves up and down along the mast 5 together with the fork 6 by the operation of the fork lift cylinder 10.

At the front of the driver's seat 7, brackets 17 are respectively provided at positions corresponding to the outside of the masts 5, and each bracket 17 has two sets of upper and lower bearings for holding the ridges 5b of the mast 5. 18 are provided. A pair of left and right chain pulleys 19 are supported at the distal ends of the piston rods of the driver's seat lift cylinder 11 via support shafts 19a. A chain 20 having a first end connected to the front of the driver's seat 7 and a second end connected to the beam 9 is wound around each chain pulley 19. The operation of the driver's seat lift cylinder 11 causes the driver's seat 7 to move up and down along the mast 5.

As shown in FIG. 3, at the front of the driver's seat 7,
An instrument panel 25 having a steering 21, a driver's seat elevating lever 22 as a driver's seat elevating operation member, a cargo handling lever 23, and a traveling lever 24 is provided.
Each of the levers 22 to 24 is configured to be independently operable. The steering 21 is a telescopic rod 26
1 and 2 are connected to a steering amount transmission system (not shown) arranged on the machine base 2. Therefore,
As the rod 26 expands and contracts as the driver's seat 7 moves up and down, the steering amount of the steering 21 is transmitted to the steering amount transmission system of the machine base 2 regardless of the height of the driver's seat 7. The left and right sides of the driver's seat 7 are open as entrances 27 each having a sufficient space for the driver to pass therethrough, and the driver can get on and off the driver's seat 7 from either left or right.

As shown in FIG. 1 and FIG.
Is formed in a shape on which an object can be placed. In this embodiment, it is processed into a horizontal plane. At the rear of the driver's seat 7, there is provided a luggage storage unit 28 which moves up and down integrally with the driver's seat 7. The luggage storage section 28 is fixed to an upper portion of a support section 7 a erected at the rear of the driver's seat 7. The luggage storage section 28 is formed so as to face the upper surface 8 a of the functional component room 8. The luggage storage unit 28 includes a top plate 28a disposed horizontally, and a wall 28b protruding downward along both sides and a rear end of the top plate 28a. Luggage storage section 28
A fence 29 is provided on the peripheral edge except for the front side.

As shown in FIGS. 1, 2, and 4, the outer surface of one mast 5 has a large number of detected parts 3 along its longitudinal direction.
0 are formed at a predetermined pitch. The pitch of the detected part 30 is set to, for example, 1 cm. As shown in FIGS. 3 and 4, a sensor 31 for detecting the detected portion 30 is attached to the bracket 17 corresponding to the mast 5 on which the detected portion 30 is formed. The sensor 31 outputs a detection signal when disposed at a position facing each of the detected parts 30. As the sensor 31, for example, a photoelectric switch is used. A reflection type photoelectric switch is used, and a reflection member is used as the detected part 30. The detected part 30 and the sensor 31 constitute a height detecting means capable of continuously detecting the height of the driver's seat 7.

As shown in FIG. 5, the bottom chamber 11a of the driver's seat lift cylinder 11 is provided with a control valve 33 through a pipe 32 for supplying and discharging hydraulic oil to and from the lift cylinder 11.
It is connected to. The control valve 33 is connected to an oil pump 35 via a hydraulic oil supply pipe (hereinafter simply referred to as a supply pipe) 34a and to an oil tank 36 via a return pipe 34b. A solenoid valve 37 is provided in the return line 34b.
Is provided. The solenoid valve 37 is constituted by an on / off valve, and is held in a closed state in an on (excited) state and is kept in an open state in an off (demagnetized) state. That is, a normally open type on / off valve is used as the electromagnetic valve 37. Note that a flow regulator valve (not shown) is provided in the middle of the pipeline 32.

The control valve 33 is composed of a manually operated valve that switches between three positions. It can be switched to the position. When the control valve 33 is disposed at the neutral position b, the control valve 33
And the communication between the two pipelines 34a and 34b is interrupted to prevent movement of the hydraulic oil in the driver's seat lift cylinder 11. Further, the control valve 33 communicates the bottom chamber 11a with the supply pipe 34a when the control valve 33 is disposed at the ascending operation position a, and connects the bottom chamber 11a to the return pipe 34b when the control valve 33 is disposed at the descending operation position c. Communicate. In the vicinity of the driver's seat lift lever 22, lift lever position sensors 38 a to 38 for detecting which of the three positions the driver's seat lift lever 22 is in.
c (shown in FIG. 5) is provided.

Next, an electrical configuration for controlling the solenoid valve 37 will be described with reference to FIG. The sensor 31 and the lift lever position sensors 38a to 38c are electrically connected to the control device 39. The control device 39 includes a CPU 4 as a control unit.
0, memory 41, excitation / demagnetization drive circuit 42, and counter 43
It has. The CPU 40 has a sensor 31 and an elevating lever position sensor 3 via an input interface (not shown).
8a to 38c and the key switch 44 of the picking forklift 1 are electrically connected. In this embodiment, the key switch 44 also serves as the descent resuming means, and the off / on operation of the key switch 44 in the closed state of the electromagnetic valve 37 is the re-descent operation of the descent resuming means.

The CPU 40 is connected to the electromagnetic section 37 via an output interface (not shown) and an excitation / demagnetization drive circuit 42. The CPU 40 is operated according to a control program stored in the memory 41, and controls the traveling motor of the picking forklift 1 and the oil pump 35 in addition to the control of the demagnetization of the electromagnetic valve 37 (opening / closing control).

The CPU 40 calculates the height of the driver's seat 7 based on the output signals of the sensor 31 and the lift lever position sensors 38a to 38c. The CPU 40 counts the ON signal output from the sensor 31 on the basis of the state in which the driver's seat 7 is located at the lowest position, and outputs the ON signal from the sensor 31 in a state where the driver's seat elevating lever 22 is located in the upward position. When input, the count value of the counter 43 is incremented by one, and when an ON signal is input from the sensor 31 in a state where the driver's seat elevating lever 22 is arranged at the lowered position, one is subtracted from the count value of the counter 43. Therefore, the value obtained by multiplying the count value of the counter 43 by a predetermined coefficient (the pitch of the detected portion 30 in this embodiment) is the height (lift) of the driver's seat 7 from the lowest position at that time. . In this embodiment, the CPU 4
0 indicates that the driver's seat 7
Judge the lift.

The CPU 40 determines whether the driver's seat lift lever 22 is in the lowered position while the driver's seat 7 is at a predetermined height Hs or lower, and during the descent from the position higher than the predetermined height Hs. When the predetermined height Hs is reached, an excitation command for closing the electromagnetic valve 37 is output to the excitation / demagnetization drive circuit 42. As the predetermined lift Hs, a value higher than the height of the load placed on the upper surface of the functional component room 8 is set. This value can be changed by operating a ten-key (not shown).

When the CPU 40 outputs an excitation command to the excitation / demagnetization drive circuit 42, the electromagnetic valve 37 is kept in an excited state until a re-lowering operation signal of the descent resuming means is input. That is,
When the key switch 44 is turned on and off in the excited state (closed state) of the solenoid valve 37, the CPU 40 releases the excitation of the solenoid valve 37.

Next, the operation of the picking forklift 1 configured as described above will be described. The driver gets into the driver's seat 7 from one of the entrances 27 formed on both the left and right sides of the driver's seat 7, and the steering 21, the driver's seat elevating lever 22, and the cargo handling lever 2 provided on the instrument panel 25.
3 and the travel lever 24 are operated. The picking forklift 1 travels according to the operation of the traveling lever 24. The driver's seat lift cylinder 11 is operated in accordance with the operation of the driver's seat lift lever 22, and the driver's seat 7 is moved up and down. The forklift cylinder 10 is operated in accordance with the operation of the cargo handling lever 23, and the fork 6 is raised and lowered.

When performing the picking operation, the picking luggage is placed on the fork 6 and the luggage storage portion 28,
The driver's seat 7 is moved up and down to a predetermined height at which loading and unloading work is required. Then, while the driver's seat 7 is held at a predetermined position, the driver performs picking work of luggage.

When the driver's seat elevating lever 22 is operated to the raised position, the bottom chamber 11a of the driver's seat lift cylinder 11 is moved.
Is supplied with hydraulic oil, and the driver's seat 7 rises. When the driver's seat elevating lever 22 is operated to the lowered position, the bottom chamber 11a
Is held in communication with the return pipe 34b, and the driver's seat 7 disposed at the ascending position is lowered by its own weight and the weight of the driver and luggage. When the driver's seat lift lever 22 is operated to the neutral position, the operation of the driver's seat lift cylinder 11 is stopped, and the driver's seat 7 is maintained at a desired height.

The sensor 31 outputs an ON signal when it is arranged at a position corresponding to the detected part 30. Accordingly, as the driver's seat 7 moves up and down, the sensor 31 intermittently outputs an ON signal corresponding to the number of the detected portions 30 through which the sensor 31 passes. The CPU 40 counts the number of the ON signals, and confirms the height of the driver's seat based on the counted number.

The solenoid valve 37 is always kept open (demagnetized state). The driver's seat 7 is arranged at a raised position, and after the picking operation at that position is completed, the driver's seat lift lever 22
Is operated, the control valve 33 is arranged at the lowering operation position c, and the driver's seat 7 starts lowering. When a detection signal indicating that the driver's seat elevating lever 22 is located at the lowered position is input, the CPU 40 reads the count value of the counter 43 and determines whether the current height is equal to or lower than a predetermined height Hs. If the lift is equal to or less than the predetermined lift Hs, an excitation command is output to the excitation / demagnetization drive circuit 42 to close the solenoid valve 37.
As a result, the solenoid valve 37 is excited and switched to the closed state, the lowering operation of the driver's seat lift cylinder 11 is restricted, and the lowering of the driver's seat 7 is stopped.

On the other hand, if the current lift is higher than the predetermined lift Hs, the solenoid valve 37 is kept in the open state and the descent is continued. The CPU 40 reads the count value of the counter 43 every predetermined time while the driver's seat 7 is descending, and outputs an excitation command to the excitation / demagnetization drive circuit 42 when the lift of the driver's seat 7 reaches the predetermined height Hs during the descent. . As a result, the solenoid valve 37 is excited and switched to the closed state, the lowering operation of the driver's seat lift cylinder 11 is restricted, and the lowering of the driver's seat 7 is stopped.

When the driver stops the lowering operation in spite of operating the driver's seat elevating lever 22 to the lowering position, there is a luggage above the functional parts room 8 except in the case of failure. It is known in advance that it is for calling attention of whether or not. Therefore, the presence or absence of the luggage in the functional parts room 8 is checked, and if there is a nearby person who needs to remove the luggage, the person is asked to remove the luggage, and then the key switch 44 is turned on and off (re-started). Lowering operation). If the stop position of the driver's seat 7 is at a height that does not hinder the driver's getting off from the driver's seat 7, the driver gets off the driver's seat 7 to remove objects, and then gets into the driver's seat 7 again. Perform the lowering operation again. C
When the PU 40 receives the ON / OFF operation signal of the key switch 44, the PU 40 issues a demagnetization command for the solenoid valve 37 to the excitation / demagnetization drive circuit
Output to As a result, the solenoid valve 37 is switched to the open state, and the driver's seat 7 resumes lowering. Therefore, it is possible to prevent the load placed on the upper surface 8a of the functional component room 8 from being crushed.

In the picking forklift 1, the driver's seat 7 in a state in which the driver's seat 7 is located at the lowest position.
Is very low compared to a normal forklift. Accordingly, in a state where the lowering of the driver's seat 7 is stopped at the predetermined lift Hs, the height of the driver's seat 7 is a height that does not hinder the driver from getting off the driver's seat 7.

Therefore, in this embodiment, the following effects can be obtained. (1) The height of the driver's seat 7 is detected by the sensor 31,
The detection signal can be used for the control of raising and lowering the driver's seat.

(2) When the driver's seat 7 is lowered from the raised position, the driver's seat 7 is lowered on the basis of the lift, despite the driver operating the driver's seat elevating lever 22 to the lowered position. By blocking, it is possible to alert the driver to whether or not there is a baggage above the functional component room 8.

(3) Since the lift can be detected continuously,
The predetermined lift Hs that regulates the lowering of the driver's seat 7 can be set at a desired position. Further, it is also possible to easily change the once set height Hs.

(4) The lift detecting means for continuously detecting the lift is moved integrally with the detection section 30 formed on the mast 5 at a predetermined pitch along the longitudinal direction thereof and the driver's seat 7. Since it is composed of the sensor 31 for detecting the detected part 30, the configuration is simplified.

(5) Even when the electromagnetic valve 37 is held in the closed state based on the height of the driver's seat 7, the electromagnetic valve 37 is switched to the open state again by the lowering operation of the descent resuming means. Descent can be easily resumed. Accordingly, the operation of preventing the driver's seat 7 from descending can be easily applied as a means for calling a driver to pay attention to whether or not there is a baggage in the upper part of the functional component room 8.

(6) The descent resuming means is operated by the key switch 44.
The space is also used, so that it is not necessary to newly secure a space for installing the descent resuming means. (7) The control valve 33 for controlling the supply and discharge of the hydraulic oil to and from the driver's seat lift cylinder 11 is constituted by a three-position switching manually operated valve, and corresponds to the raising, neutral and lowering operations of the driver's seat lifting lever 22. As a result, the position is switched to three positions of the ascending operation position a, the neutral position b, and the descending operation position c. Accordingly, the driver's seat 7 is moved up and down according to the driver's intention.

(8) Since a normally open type on / off valve is used for the solenoid valve 37, the driver's seat 7 can be lowered even when power is not supplied to the solenoid valve 37 due to a failure or the like. Becomes

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. This embodiment is different from the above-described embodiment in that when the driver's seat 7 reaches a preset lift when ascending, it can be automatically stopped. The same parts as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

An electromagnetic valve 45 is provided in the supply line 34a. As the solenoid valve 45, a normally open type on / off valve is used. The CPU 40 is connected to a solenoid valve 45 via an output interface (not shown) and an excitation / demagnetization drive circuit 42. As for the hardware configuration, the above point is different from the above embodiment, and the other configuration is the same.

The memory 41 stores a predetermined stop position corresponding to the height of the shelf when the picking operation is performed.
This stop position is set to a value different from the predetermined lift Hs. The CPU 40 outputs an excitation command for the electromagnetic valve 45 when the height of the driver's seat 7 coincides with the stop position while the driver's seat 7 is being raised or lowered based on the raising or lowering operation of the driver's seat lifting lever 22. After the excitation command is output, a demagnetization command for the solenoid valve 45 is output after a lapse of a predetermined time. The predetermined time is set to a time required for the driver to notice the stop of the driver's seat 7 and return the driver's seat elevating lever 22 to the neutral position.

Therefore, in this embodiment, when the driver raises or lowers the driver's seat lift lever 22 during the picking operation, the driver's seat 7 starts raising or lowering in accordance with the operated position. When the driver's seat 7 reaches a predetermined stop position suitable for picking work, the solenoid valve 45 is closed, and the driver's seat 7 is temporarily stopped. If the position is a position corresponding to the shelf desired by the driver, the driver returns the driver's seat elevating lever 22 to the neutral position. If the position is different from the rack desired by the driver, the driver holds the driver's seat elevating lever 22 at the same position. Since the solenoid valve 45 is opened after a predetermined time, the driver's seat 7 starts moving again. Other operations are the same as those of the first embodiment.

Therefore, in this embodiment, the following effects can be obtained in addition to the effects (1) to (8) of the above embodiment. (9) Since the driver's seat 7 automatically stops at an appropriate height corresponding to the height of the shelf during the picking operation, it is easy to stop the driver's seat 7 at a position suitable for the picking operation.

(10) It can be implemented by a simple hardware modification of adding an electromagnetic valve 45 to the configuration of the above embodiment. The embodiment is not limited to the above, and may be embodied as follows, for example.

Instead of providing the detection part 30 of the lifting height detecting means on the mast 5, it is provided on the back surface of the support part 7 a of the driver's seat 7 as shown in FIG. You may. In this case, unlike the above embodiment,
Since the sensor 31 does not move integrally with the driver's seat 7 and is always fixed at a predetermined position on the machine base 2, wiring for electrically connecting the sensor 31 and the control device 39 is simplified.

In the first embodiment, the height of the driver's seat 7 is equal to or higher than a predetermined height, instead of using the means for detecting the height of the driver's seat 7 which can detect the height over almost the entire range of the vertical movement of the driver's seat 7. It is configured to detect whether or not it is. For example, the detection target portion 30 is formed to have a shape that continuously extends above the predetermined height of the mast 5 or below the predetermined height. Also in this case, the effects (1), (2), (5) to (8) of the first embodiment can be obtained.

The height detecting means may be configured to detect that the driver's seat 7 is arranged at a plurality of predetermined locations, that is, to detect only the height to be detected corresponding to a predetermined purpose. For example, at the position corresponding to each lift to be detected,
Detected portions that can be distinguished from other detected portions are provided.
It can be easily implemented by providing a barcode as the detected part and using a barcode reader as a sensor for detecting the detected part. Also, arrange multiple sets of sensors at the same height,
A configuration may be adopted in which the number and the positions of the detected parts simultaneously detected by the plural sets of sensors are changed. In this case, it can be easily confirmed whether or not the driver's seat 7 has reached a lift corresponding to a predetermined purpose.

A proximity switch may be used as the sensor 31 instead of the photoelectric switch. Since the mast 5 and the functional component room 8 are generally made of metal, a mounting plate for the detection unit 30 is formed of a nonmagnetic material such as resin, and the detection unit 30 made of a magnetic material such as metal is mounted thereon. In addition, the sensor 31
May be used as a limit switch.

When the driver's seat 7 reaches the predetermined lift Hs during the descent from the position higher than the predetermined lift Hs, the solenoid valve 37 is immediately closed to stop the descent of the driver's seat when the driver's seat 7 reaches the predetermined lift Hs. Then, the vehicle is decelerated and then stopped. For example, an on / off solenoid valve is provided in series with the solenoid valve 37 in the return pipe 34b, and a bypass pipe having a throttle valve is provided in parallel with the on / off solenoid valve. The on / off solenoid valve is kept open when it does not reach the predetermined lift Hs. Then, when the predetermined lift Hs is reached, CP
U40 immediately switches the on / off solenoid valve to the closed state, starts counting by the timer, and switches the solenoid valve 37 to the closed state after a predetermined time. In this case, the descent speed of the driver's seat 7 is reduced and then stopped. Therefore, it is possible to prevent the shock caused by the sudden stop of the driver's seat 7 from being applied to the driver and the luggage placed on the luggage storage unit 28.

In the stop control during the descent of the driver's seat 7, it is confirmed from the lift (the count value of the counter 43) that the vehicle has reached a position that is approached a predetermined distance from the position to be stopped, and deceleration is started at that time. It may be configured. In this case, a timer is not required, and the height detecting means can be effectively used.

In place of the configuration in which the key switch 44 also serves as the descent resuming means, a dedicated descent resuming means, for example, a push button switch or a toggle switch may be provided. Further, the operation of moving the driver's seat elevating lever 22 from the lowering operation position to the neutral position, and then returning to the lowering operation position again may be a re-lowering operation. In this case, the CPU 40 determines the presence or absence of the re-lowering operation based on the output signals of the lifting lever position sensors 38b and 38c that detect the neutral position and the lowering operation position of the driver's seat lifting lever 22.

The height detection data of the driver's seat 7 may be used for another control. For example, when the driver's seat 7 is arranged at a position higher than a predetermined height, the traveling speed of the picking forklift 1 is reduced to a predetermined ratio (for example, half) of the traveling speed when the driver's seat 7 is arranged at the lowest position. And

The notification means may be activated when the driver's seat 7 stops halfway down. The notification means includes a buzzer, a lamp and the like. In this case, it helps to draw the driver's attention.

A three-position switching solenoid valve is used as the control valve 33 instead of the manually operated valve. Then, the electromagnetic valve 37 is eliminated, and the stop function performed by the electromagnetic valve 37 is performed by the three-position switching electromagnetic valve. In this case, driver's seat 7
A push button switch may be used instead of the lever as a driver's seat elevating operation member for instructing elevating.

The luggage storage section 28 has a structure in which the lower part can be visually recognized. For example, most of the luggage storage unit 28 is formed of a transparent material, is formed in a lattice shape, or is formed of a punched metal or a net. In this case, it becomes easier for the driver to confirm whether or not the luggage is erroneously placed on the luggage storage unit 28.

The technical ideas (inventions) other than those described in the claims, which can be understood from the above embodiments, will be described below together with their effects. (1) In the invention according to claim 5, the control valve is a three-position switching manually operated valve, and supplies the hydraulic oil to the bottom chamber in accordance with the raising, neutral, and lowering operations of the driver's seat elevating operation member. A position to communicate with the pipe, a position to make the bottom chamber uncommunicable with the hydraulic oil supply pipe and the return pipe,
The position is switched to a position where the bottom chamber communicates with the return line. In this case, the supply and discharge of hydraulic oil to the driver's seat lift cylinder is controlled in accordance with the raising, neutral, and lowering operations of the driver's seat raising / lowering operation member, and compared with the case where a solenoid valve using a push button switch is used. As a result, operation errors are reduced, and the driver's seat is raised and lowered by the driver's will.

(2) In the invention according to claim 6,
The descent resuming means is also used as a key switch of the picking forklift, and the off / on operation of the key switch in the closed state of the solenoid valve is the descent resumption operation of the descent resumption means. In this case, since the key switch also serves as the descent resumption means, it is not necessary to newly secure a space for installing the descent resumption means.

[0066]

As described in detail above, claims 1 to 6 are provided.
According to the invention described in (1), the lift of the driver's seat is detected by the lift detecting means, and the detection signal can be used for the control of raising and lowering the driver's seat.

According to the second aspect of the present invention, it is possible to easily confirm whether or not the driver's seat has reached a height corresponding to a predetermined purpose. According to the third aspect of the present invention, since the lift can be continuously detected, the predetermined lift for restricting the lowering of the driver's seat can be set to a desired position. In addition, it is possible to easily change the predetermined lift once set.

According to the fourth aspect of the invention, the structure of the lift detecting means for continuously detecting the lift is simplified. According to the fifth aspect of the present invention, the lowering is prevented, even if the driver operates the driver's seat elevating operation member to the lowering position. Attention can be given to whether or not there is luggage above the room.

According to the sixth aspect of the present invention, even when the solenoid valve is kept closed based on the elevation of the driver's seat,
The descent of the driver's seat can be restarted by the descent operation of the descent resuming means. Therefore, the descent prevention operation of the driver's seat can be easily applied as a means for calling the driver to pay attention to the situation below.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a picking forklift according to a first embodiment.

FIG. 2 is a schematic side view of a state in which a driver's seat is similarly arranged at a lowermost position.

FIG. 3 is a schematic partial plan view of a picking forklift.

FIG. 4 is a schematic partial perspective view showing an arrangement state of a lift detecting means.

FIG. 5 is a hydraulic circuit diagram for a driver's seat lift cylinder.

FIG. 6 is a hydraulic circuit diagram for a driver's seat lift cylinder according to a second embodiment.

FIG. 7 is a schematic side view showing an arrangement of a lift detecting means according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Picking forklift, 2 ... Machine stand, 6 ... Fork, 7 ... Driver's seat, 11 ... Driver's seat lift cylinder, 11
a: bottom chamber, 22: driver's seat elevating lever as driver's seat elevating operation member, 28: luggage storage part, 30: detected part constituting height detecting means, 31: sensor similarly, 33 ... control valve, 34b ... Return line, 36 ... oil tank, 37 ... solenoid valve, 40 ... CPU as control means, 44 ... Key switch also serving as re-lowering means.

Claims (6)

[Claims] 1. A fork and a driver's seat are both independently movable up and down with respect to a machine stand, and the fork is provided at a front part of the machine stand, and is integrated with a driver's seat at a rear part of the driver's seat. A picking forklift having a luggage storage section that moves up and down in the picking forklift, the picking forklift having a height detecting means for detecting the height of the driver's seat. 2. The picking forklift according to claim 1, wherein the lift detecting means is configured to detect that the driver's seat is disposed at a plurality of predetermined locations. 3. The picking forklift according to claim 1, wherein the lift detecting means is configured to be able to continuously detect the lift of the driver's seat. 4. A detection part formed at a predetermined pitch along a longitudinal direction of a mast for guiding the elevation of the driver's seat, the lift detection means, and the detection part moved integrally with the driver's seat. The picking forklift according to claim 3, further comprising: a sensor for detecting the forklift. 5. The picking forklift further comprises: a control valve for controlling supply and discharge of hydraulic oil to a driver's seat lift cylinder for raising and lowering the driver's seat; a driver's seat lifting / lowering operating member for operating the control valve; A solenoid valve provided in a return line of a hydraulic circuit for communicating a bottom chamber of the driver's seat lift cylinder with an oil tank in a state where the driver's seat elevating operation member is operated to the lowered position; and While in the open state, based on the detection signal from the height detecting means, when the driver's seat lift operation member is disposed at the lowered position in a state where the driver's seat height is not more than a predetermined lift, and Control means for closing said solenoid valve when said predetermined height is reached during descent from a position higher than said predetermined height. Pickin described Forklift. 6. The control device according to claim 1, wherein the electromagnetic valve is reopened based on a re-lowering operation of the descent resuming unit, even when the detection signal indicating the predetermined height is being output from the height detecting unit. The picking forklift according to claim 5, wherein