JPH11240699A - Picking forklift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a load put on a functional-part compartment placed on the rear part of a chassis from being damaged when the driver not knowing the presence of the load starts to lower the driver's cab. SOLUTION: A frame 2 is mounted on its rear portion with a functional-part compartment 8 with a top shaped to receive loads placed thereon. A driver's cab 7 adapted to be moved vertically by the operation of a driver's-cab lift cylinder is provided at its rear portion with a load rest part 28 adapted to be moved vertically together with the driver's cab 7 and opposed to the functional-part compartment 8. A detection member 30 is placed below the load rest part 28 so as to swing to or from it, and a detection switch 31 is arranged above the detection switch 30 to output a detection signal when the detection switch 30 swings up beyond a predetermined distance. When the detection switch 31 detects any object put on the functional-part compartment 8, a solenoid valve interposed in a return pipeline that connects the bottom chamber of the driver's-cab lift cylinder to an oil tank is closed to check the lowering motion of the driver's cab 7.

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 functional component room is provided at a rear portion of a machine base. Things.

[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 has a state in which there is a slight gap above the functional component room. However, when the driver's seat is raised, a large space is created above the functional component 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, the luggage placed above the functional component room may be crushed by the luggage storage unit and may be damaged, or the luggage storage unit may be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object the object of the present invention in which luggage is placed above a functional component room provided at the rear of a machine, and the driver does not know it. Another object of the present invention is to provide a picking forklift capable of preventing the load placed on the upper side of the functional component room from being damaged by starting to lower the driver's seat.

[0006]

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 fork is provided at the front of the machine base, a functional component room is provided at the rear of the machine base, and the upper side of the functional component room is formed in a shape capable of placing an object, and the fork is driven behind the driver's seat. In a picking forklift formed such that a luggage storage unit that moves up and down integrally with the seat is opposed to the functional parts room, a control valve that controls supply and discharge of hydraulic oil to a driver's seat lift cylinder that moves up and down the driver's seat. A driver's seat elevating operation member that operates the control valve, and a return of a hydraulic circuit that communicates a bottom chamber of the driver's seat lift cylinder with an oil tank when the driver's seat elevating operation member is operated to a lowered position. An electromagnetic valve provided in the road, and capable of detecting detection means those which are placed on the upper side of the functional component compartment,
A control unit for opening the solenoid valve when the detection signal is not output from the detection unit and for closing the solenoid valve based on the detection signal of the detection unit.

According to a second aspect of the present invention, in the first aspect of the present invention, the control valve is a three-position switching manually operated valve, and corresponds to the raising, neutral and lowering operations of the driver's seat raising and lowering operation member. A position at which the bottom chamber communicates with the hydraulic oil supply line, a position at which the bottom chamber cannot communicate with the hydraulic oil supply line and the return line, and a position at which the bottom chamber communicates with the return line. Can be switched to

According to a third aspect of the present invention, in the first or second aspect of the present invention, the detecting means can be moved up and down integrally with the luggage storage portion, and the luggage storage portion is provided below the luggage storage portion. A detection member provided so as to be able to move up and down relatively with respect to a detection switch disposed above the detection member and outputting a detection signal when the detection member moves upward by a predetermined amount or more; It has.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the detection means is provided on a support piece provided so as to protrude downward from a lower end of the luggage storage portion. And a light emitting unit and a light receiving unit.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the detection means outputs a detection signal when a predetermined load or more is applied to the upper side of the functional component chamber. It is.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the control means is configured to perform the control based on the re-descent operation of the descent resuming means even when the detection signal is being output from the detection means. The solenoid valve is opened again.

According to a seventh aspect of the present invention, in the invention of the sixth aspect, the descent resuming means is also used as a key switch of a picking forklift, and the key switch is turned on and off when the solenoid valve is closed. Is the re-descent operation of the descent resuming means.

According to the first aspect of the present invention, supply and discharge of hydraulic oil to and from the driver's seat lift cylinder are controlled via the control valve by operating the driver's seat elevating operation member. When the detecting means detects an object placed on the upper side of the functional component chamber, 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 closed, and the operation is stopped. The seat is prevented from descending. Therefore, when the driver lowers the driver's seat without knowing that the luggage is placed on the upper side of the functional parts room, the luggage is prevented from being caught and damaged by the luggage compartment and the functional parts room. You.

According to a second aspect of the present invention, in the first aspect of the present invention, the control valve is manually switched to three positions. The control valve is switched to a position where the bottom chamber cannot be communicated with the hydraulic oil supply line and the return line by a neutral operation of the driver's seat elevating operation member. In addition, the bottom chamber is switched to a position where the bottom chamber communicates with the hydraulic oil supply pipe by an ascending operation of the driver's seat elevating operation member, and a position where the bottom chamber is communicated with the return pipe by a descending operation of the driver's seat elevating operation member.

According to a third aspect of the present invention, in the first or second aspect of the present invention, when the luggage storage unit is lowered together with the driver's seat in a state where the luggage is placed above the functional component room, the operation is started. Before the seat reaches the lowermost position, the detection member contacts the baggage. When the driver's seat is further lowered from that state, the detection member is moved upward and a detection signal is output from the detection switch. Then, the solenoid valve is closed based on the output signal, and the lowering of the driver's seat is stopped.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, if the luggage is placed above the functional component room, the light emitted from the light emitting unit is applied to the luggage. It is blocked and does not reach the light receiving portion, and the presence of the baggage is detected.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, when a predetermined load or more is applied to the upper side of the functional component room, the detection switch is turned on regardless of the position of the driver's seat. A detection signal is output. Then, the solenoid valve is closed based on the output signal, and the lowering of the driver's seat is prevented.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, even if the detection signal is output from the detection means, when the descent resumption means is operated again, the control means causes the control means to perform the operation. The solenoid valve opens again,
The driver's seat resumes descending.

According to a seventh aspect of the present invention, in the sixth aspect of the invention, when the key switch of the picking forklift is turned off and on in the closed state of the solenoid valve, the solenoid valve is again opened. Then the driver's seat resumes descending.

[0020]

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. 5, a pair of left and right masts 5 are formed with grooves 5a which are open inward on the inner side surfaces (opposing surfaces) along the longitudinal direction 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 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 outer sides of the masts 5, and each bracket 17 has two sets of upper and lower bearings for holding the ridges 5 b 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. 5, 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, a luggage storage unit 28 that moves up and down integrally with the driver's seat 7 is provided.
Is provided. The luggage storage section 28 is formed so as to face the upper surface 8 a of the functional component room 8. Luggage storage part 2
8 has a top plate 28a disposed horizontally, and a wall 28b protruding downward along both sides and a rear end of the top plate 28a.

In the luggage compartment 28, the driver's seat 7 is being lowered from the raised position to the lowermost position while the upper surface 8a of the functional component room 8 is being moved.
Is provided with a detecting means 29 capable of detecting an object placed on the cradle. A detection member 29 rotatably provided on the luggage storage portion 28 and disposed so as to be inclined downward and obliquely rearward from the luggage storage portion 28;
And a detection switch 31 for detecting the rotation of zero.

The detecting member 30 is formed of a flat plate having substantially the same shape as that of the luggage storage portion 28, and has bearing portions 30a (shown in FIG. 4) on the right and left sides of the base end. A support shaft 32 projecting from a wall 28b of the luggage storage portion 28
The detection member 30 is rotatably supported by the luggage storage section 28 in a state in which is inserted into the bearing section 30a. Detection member 3
Reference numeral 0 denotes a state in which the base end is in contact with the top plate 28a of the luggage storage unit 28, thereby restricting downward rotation (reference position).
Thus, it is arranged so as to be inclined downward and obliquely rearward from the luggage storage unit 28. The detection member 30 is arranged so that the driver's seat 7 is located at the lowest position and is not rotated upward from the reference position unless there is a load on the upper surface 8a of the functional component room 8.

A limit switch is used as the detection switch 31. The detection switch 31 is engaged with the detection member 30 when the detection member 30 rotates upward from the reference position, and the detection member 30 is moved upward by a predetermined amount or more. Outputs a detection signal when rotated.

As shown in FIG. 6, the bottom chamber 11a of the driver's seat lift cylinder 11 is provided with a control valve 34 through a pipe 33 for supplying and discharging hydraulic oil to and from the lift cylinder 11.
It is connected to. The control valve 34 is connected to an oil pump 36 via a hydraulic oil supply pipe (hereinafter simply referred to as a supply pipe) 35a and to an oil tank 37 via a return pipe 35b. A solenoid valve 38 is connected to the return line 35b.
Is provided. The solenoid valve 38 is constituted by an on / off valve, and is kept 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 38. A flow regulator valve (not shown) is provided in the middle of the pipe 33.

The control valve 34 is composed of a manually operated valve that switches between three positions, and corresponds to three operation positions of an ascending operation position a, a neutral position b, and a descending operation position c corresponding to the ascending, neutral, and descending operations of the driver's seat elevating lever 22. It can be switched to the position. When the control valve 34 is located at the neutral position b, the control valve 34
And the communication between the two pipelines 35a and 35b is blocked to prevent the movement of hydraulic oil in the driver's seat lift cylinder 11. Further, the control valve 34 connects the bottom chamber 11a to the supply pipe 35a when the control valve 34 is disposed at the ascending operation position a, and connects the bottom chamber 11a to the return pipe 35b when the control valve 34 is disposed at the descent operation position c. Communicate.

The detection switch 31 is electrically connected to solenoid valve control means 39 as control means for supplying an exciting current to the solenoid valve 38. The solenoid valve control means 39 is composed of, for example, a relay, and its normally open contact is connected in series with the solenoid of the solenoid valve 38. And the solenoid valve control means 3
9 supplies the exciting current to the electromagnetic valve 38 when the detection switch 31 is on, and stops supplying the exciting current when it is off.

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 a state of communication with the return pipe 35b, and the driver's seat 7 disposed at the ascending position is lowered by its own weight and the weight of the driver and the load. 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 upper surface 8 of the functional parts room 8 is
When the driver's seat elevating lever 22 is operated to descend while the object (luggage) is placed on a, the control valve 34 is arranged at the descending operation position c, and the operator's seat 7 starts to descend. During the downward movement, the detection member 30 engages with the object placed on the upper surface 8 a of the functional component chamber 8. If the driver's seat 7 continues to descend further in this state, the detection member 30 is rotated upward, the detection switch 31 is turned on, and a detection signal is output. Then, the electromagnetic valve 38 is excited by the operation of the electromagnetic valve control means 39 based on the detection signal, and the electromagnetic valve 38 is closed so as to shut off the return line 35b, thereby preventing discharge of the hydraulic oil from the bottom chamber 11a. The descent of the driver's seat 7 is stopped. Therefore, the functional parts room 8
It is possible to prevent the object placed on the upper surface 8a from being crushed or the detecting means 29 from being damaged.

When the driver stops the driver's seat 7 before reaching the re-lowering position, the driver determines that the detecting means 29 has detected an object, and operates the driver's seat lifting / lowering lever 22 to the neutral position. Then, the state of the object is determined by looking at the lower side of the luggage storage unit 28, and it is determined whether the lowering is impossible unless the object is removed. If a person needs to be removed and there is a person nearby, the driver removes the object and then operates the driver's seat elevating lever 22 to the lowered position. As a result, the driver's seat 7 resumes descending. 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. To operate the driver's seat elevating lever 22 to the lowered position.

In the picking forklift 1, the driver's seat 7
The height of the floor of the driver's seat 7 in a state in which is located at the lowest position is very low as compared with a normal forklift. Therefore, unless the height of the object placed on the upper surface 8a of the functional component room 8 is very high, the detecting means 29 is not connected to the upper surface 8a.
In the state in which the lowering of the driver's seat 7 is stopped by detecting an object placed on the driver's seat 7, the height of the driver's seat 7 becomes a height that does not hinder the driver from getting off the driver's seat 7.

The detecting means 29 is not limited to the one mounted on the upper surface 8a of the functional component room 8, but may be an object temporarily disposed above the functional component room 8, for example, a transport stopped near a picking forklift. In some cases, a part of the load loaded while protruding into the vehicle is detected. In this case, the driver's seat 7 may stop at a high position. At this time, the driver's seat lifting lever 22 is operated to the ascending position to slightly raise the driver's seat 7 to disengage the detection member 30 from the load, and then to the neutral position. The traveling lever 24 is operated to make the picking forklift 1 travel forward. Then, at a position where the load does not exist above the functional component room 8, the driver's seat elevating lever 22 is operated to the lowered position.

Therefore, in this embodiment, the following effects can be obtained. (1) The detecting means 29 is located above the functional component room 8 (the upper surface 8
When an object placed on the driver's seat 7 is detected, the solenoid valve 38 provided in the return pipe 35b connecting the bottom chamber 11a of the driver's seat lift cylinder 11 to the oil tank 37 is closed. Is blocked. Therefore, when the driver lowers the driver's seat 7 without knowing that the luggage is placed above the functional component room 8, the luggage is caught and damaged by the luggage storage portion 28 and the functional component room 8. Is avoided.

(2) A control valve 34 for controlling the supply and discharge of hydraulic oil to and from the driver's seat lift cylinder 11 is constituted by a manually operated valve that switches between three positions.
The position is switched to three positions of an ascending operation position a, a neutral position b, and a descending operation position c in response to the neutral and descending operations. Therefore,
The driver's seat 7 is moved up and down at will of the driver.

(3) The detecting means 29 moves up and down integrally with the luggage storage portion 28, and when the luggage storage portion 28 continues to descend while the detection member 30 is engaged with an object, the detection member 30 moves upward. A detection switch 31 that outputs a detection signal is provided. Then, the driver's seat 7 is lowered while an object is placed above the functional component room 8, and a detection signal is output from the detection switch 31 while the detection member 30 is engaged with the object while the driver's seat 7 is being lowered. Is output. Therefore, there is a high probability that the height of the driver's seat 7 when stopped halfway does not hinder the driver from getting off the driver's seat 7, and the driver gets off the driver's seat 7 to remove the object. It can be performed.

(4) The detection member 30 is formed of a flat plate that is rotatably provided in the luggage storage section 28 and that is disposed so as to be inclined downward and obliquely rearward from the luggage storage section 28. Therefore, the structure for moving the detection member 30 up and down relatively to the luggage storage section 28 is simplified.

(5) Since the detection member 30 is rotatably supported by the support shaft 32 projecting from the wall 28b of the luggage storage portion 28, the support piece for supporting the support shaft 32 is The configuration for rotatably supporting the detection member 30 is simpler than the configuration in which the detection member 30 protrudes from the top plate 28a.

(6) Since a limit switch is used as the detection switch 31, a malfunction does not easily occur as compared with a non-contact type switch. (7) Since a normally open type on / off valve is used for the solenoid valve 38, the power supply is
The driver's seat 7 can be lowered even when it is not supplied to the vehicle.

(Second Embodiment) Next, a second embodiment will be described with reference to FIGS. In this embodiment, the point that the detecting means 29 is provided on the functional component room 8 side irrespective of the lifting / lowering of the luggage storage part 28, and the state in which the detection signal is output from the detecting means 29, This embodiment is different from the above-described embodiment in that the solenoid valve 38 can be opened based on the descending operation. Functional parts room 8
A flat plate 40 is disposed on the upper side of the upper side so as to be slightly vertically movable. The flat plate 40 is supported by a plurality of (for example, four) extendable struts 41, and the strut 41 is in a state where the strut 41 is most extended in a state where no load is applied on the flat plate 40. A detection switch 42 is provided below the flat plate 40.
The detection switch 42 outputs a detection signal when a load greater than a predetermined value is applied.

As shown in FIG. 8, the detection switch 42 is electrically connected to electromagnetic valve control means 39 for supplying an exciting current to the electromagnetic valve 38. The electromagnetic valve control means 39 supplies the exciting current to the electromagnetic valve 38 when the detection switch 42 is on, and stops supplying the exciting current when it is off. The solenoid valve control means 39 is integrated into a control device 43 for controlling the traveling motor of the picking forklift 1 and the oil pump 36. In this embodiment, the key switch 44 of the picking forklift 1 also serves as a descent resuming unit, and the key switch 4 in the closed state of the solenoid valve 38 is used.
The off / on operation of No. 4 is the re-lowering operation of the descent resuming means. In this embodiment, the control device 43 constitutes control means together with the solenoid valve control means 39.

When the detection signal is output from the detection switch 42 while the key switch 44 is on, the control device 43
Until the detection signal is no longer output from the detection switch 42, the electromagnetic valve 38 is held in the excited state via the electromagnetic valve control means 39. When the key switch 44 is turned on and off while the solenoid valve 38 is in the excited state (closed state), the excitation of the solenoid valve 38 by the solenoid valve control means 39 is released.

In this embodiment, when an object is placed on the flat plate 40 and a predetermined load or more is applied to the flat plate 40, a detection signal is output from the detection switch 42 regardless of the position of the driver's seat 7. Then, based on the output signal, the electromagnetic valve 38 is closed, and the lowering of the driver's seat 7 is prevented. Therefore,
Even if there is a sufficient distance between the luggage storage unit 28 and the object, the driver's seat 7 cannot be lowered as it is, and the driver's seat 7 is raised to a height where it is not easy for the driver to get off the driver's seat 7. If an object is placed on the flat plate 40 in this state, there is a problem.

However, if the key switch 44 serving as the descent resuming means is turned on / off (re-descent operation) in a state where the detection signal is being output from the detection switch 42, the control device 43 receives the signal based on the signal. The excitation of the solenoid valve 38 is released. Therefore, the solenoid valve 38 is opened and the driver's seat 7 starts to descend. At this time, the driver measures the height of the object placed on the flat plate 40 before the lowermost operation, and operates the driver's seat elevating lever 22 so that the luggage storage unit 28 stops above the height.

Therefore, in this embodiment, the following effects can be obtained in addition to the effects (1), (2), (6) and (7) of the above embodiment. (8) The detection switch 42 is different from the above embodiment,
The wiring for electrically connecting the detection sensor 42 and the solenoid valve control means 39 or the control device 43 is simple because it is always fixed at a predetermined position of the machine base 2 without moving integrally with the luggage storage portion 28. Become.

(9) Even if the detection switch 42 is in the ON state, the descent of the driver's seat 7 can be restarted by the descent operation of the descent resuming means. Therefore, even if the height of the object placed on the flat plate 40 is high and the object cannot be removed because there are no nearby people, if the damage of the object is accepted, the driver's seat 7 can be lowered, and the driver's seat 7 can be moved down. The driver stops at a high position and the driver
It is possible to avoid getting stuck.

(10) Since the key switch also functions as the descent resuming means, it is not necessary to newly secure a space for installing the descent resuming means. The embodiment is not limited to the above, and may be embodied as follows, for example.

A proximity switch may be used as the detection switches 31 and 42 instead of the limit switch.
In this case, the detection member 30 and the flat plate 40 are formed of metal,
The distance between the proximity switch and the detection member 30 or the flat plate 40 is set to a predetermined distance. Alternatively, the detection member 30 and the flat plate 40 may be formed of a non-magnetic material such as a resin, and a magnetic material such as a metal may be fixed at a position facing the proximity switch.

The detecting means 29 which moves integrally with the luggage storage section 28 is provided by a photoelectric switch or an optical sensor.
While the light emitted from the light emitting part is received by the light receiving part,
The configuration may be such that the presence or absence of an object is detected based on a change in the amount of light received by the light receiving unit. For example, the light projecting unit and the light receiving unit are supported by a support piece disposed so as to protrude below the lower end of the luggage storage unit 28. Then, based on an output signal from the light receiving unit, the solenoid valve control unit 39 excites and demagnetizes the solenoid valve 38. In this case, by changing the length of the support piece that supports the light emitting unit and the light receiving unit, the distance between the object and the lower end of the baggage storage unit 28 in the state where the object is detected can be easily changed. Adjustment (setting) of the position at which the detecting means 29 can detect an object in a state where the descent of the driver's seat 7 can be stopped so that the placing portion 28 does not collide with the object is facilitated.

When the detecting means 29 is constituted by a photoelectric switch or an optical sensor, as shown in FIG.
A reflection member 46 serving as a reflection portion for reflecting the light projected from a is provided on a support piece 28c fixed to the left and right walls 28a of the luggage storage section 28. After the light is reflected a plurality of times by the reflection member 46, the light enters the light receiving portion 45b.
In this case, one light emitting part 45a and one light receiving part 45b
However, it can be detected whether or not an object is placed in almost the entire area above the functional component room 8.

○ As a photoelectric switch or an optical switch,
A light emitting unit and a light receiving unit integrally formed, that is, a reflection type may be used. In the second embodiment, a photoelectric switch or an optical switch may be provided as the detection unit 29. For example, a light projecting unit, a light receiving unit, and a reflecting plate are provided on the support pieces protruding from the left and right sides or the front and rear sides of the upper wall of the functional component room 8 in the same manner as described above. In this case, substantially the same effects as in the second embodiment can be obtained.

When a photoelectric switch or an optical switch is provided as the detection means 29, a plurality of photoelectric switches or optical switches may be provided, and the light emitted from each switch may be directly received without passing through the reflection plate.

In the case where the detecting means 29 is provided on the functional component room 8 side as in the second embodiment, supporting portions are provided on the left and right sides near the front side of the functional component room 8, and the supporting portions are flat. Are rotatably supported. Further, an urging means for holding the detecting member in a state of being inclined upward and obliquely backward may be provided, and a detecting switch for detecting the downward rotation of the detecting member may be provided below the detecting member. A limit switch or the like is used as the detection switch. In this case, substantially the same effects as those of the second embodiment can be obtained, and the structure for supporting the detection member can be simplified.

When the detecting means 29 is provided on the functional component room 8 side as in the second embodiment, a strain gauge (strain gauge) is attached to the upper wall of the functional component room 8 without providing the flat plate 40. An output signal of a bridge circuit incorporating a strain gauge detects whether an object is placed or not. In this case, there is no need to provide the flat plate 40 above the functional component chamber 8, and the configuration becomes simpler.

In the first embodiment, a plate having substantially the same shape as the upper surface of the functional component room 8 is attached to the lower surface of the luggage storage unit 28 via a spring as the detecting means 29, and the detecting switch 31 is disposed above the plate. May be provided. Also in this case, (1) to (3) and (6) of the first embodiment.
The effect of is obtained.

In the first embodiment, the detecting means 2
9, the detection member 30 is not a plate but is substantially U-shaped.
It may be constituted by a bar 31 bent and formed in a letter shape or a V shape, or may be constituted by a lattice-like member.

In the configuration in which the detecting means 29 moves up and down integrally with the luggage storage section 28 as in the first embodiment,
Instead of the configuration in which the electromagnetic valve 38 is immediately closed to stop the lowering of the driver's seat based on the detection signal of the detection means, the deceleration is performed once and then stopped. For example, as shown in FIG. 10, an on / off solenoid valve 47 is provided in series with the solenoid valve 38 in the return line 35b, and the on / off solenoid valve 47 is provided.
A bypass pipe 35c provided with a throttle valve 48 is provided in parallel with the above. The on / off solenoid valve 47 is kept open when no detection signal is output from the detection switch 31. When the detection signal is output from the detection switch 31, the solenoid valve control unit 39 immediately turns on and off the solenoid valve 47.
Is switched to a closed state, and counting is started by a timer (not shown), and after a predetermined time, the electromagnetic valve 38 is switched to a closed state. In this case, the operating oil is immediately supplied to the bypass line 35c based on the detection signal of the detection switch 31.
, And after the descent speed of the driver's seat 7 is reduced, the operation is 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 second embodiment, instead 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, a detection switch for detecting the neutral position and the lowering operation position of the driver's seat elevating lever 22 is provided, and after the driver's seat elevating lever 22 is moved from the lowering operation position to the neutral position, the operation of returning to the lowering operation position is again lowered. As an operation, the driver's seat elevating lever 22 may be configured to double as the descent resuming means.

The notification means may be operated while the detection signal is being output from the detection means 29. The alarm means includes an alarm buzzer, an alarm lamp, and the like. The operation of the notification means may be intermittent, that is, the alarm buzzer may sound intermittently or the alarm lamp may blink. In this case, it helps to draw the driver's attention.

The technical ideas (inventions) other than those described in the claims that can be understood from the above embodiments will be described below together with their effects. (1) In the invention according to claim 3, the detection member is rotatably provided on the luggage storage portion and is disposed so as to be inclined downward and obliquely rearward from the luggage storage portion. In this case, the configuration in which the detection member is moved up and down relatively with respect to the luggage storage section is simplified.

(2) In the invention according to claim 4,
The light-emitting unit is opposed along left and right sides or front and rear sides so as to protrude from a lower end of the luggage storage unit, and is provided to reflect light emitted from the light-emitting unit at a plurality of different positions. The light receiving section is provided at a position where light is emitted toward the section, and the light receiving section is provided at a position where light reflected from the reflecting section is received. In this case, the presence or absence of an object can be detected in a wide range only by providing one light emitting unit and one light receiving unit.

[0067]

As described in detail above, claims 1 to 7 are provided.
According to the invention described in the above, in a state where the luggage is placed above the functional component room provided at the rear of the machine base, the driver starts lowering the driver's seat without knowing and the upper part of the functional component room is Damage to the loaded luggage can be prevented.

According to the second aspect of the present invention, the supply and discharge of hydraulic oil to and from the driver's seat lift cylinder are controlled by the three-position switching manually operated valve. , Operated in response to neutral and lowering operations,
The driver's seat is raised and lowered by the driver's will.

According to the third aspect of the present invention, the descent is stopped in a state where the detecting member is engaged with the object placed above the functional component chamber during descent of the driver's seat, so that the descent is stopped halfway. It is highly probable that the height of the driver's seat at the time when the driver does not hinder the driver from getting off the driver's seat is high, and the driver can get off the driver's seat and perform the work of removing objects.

According to the fourth aspect of the present invention, the distance between the object and the lower end of the baggage storage unit in a state where the object is detected is changed by changing the length of the support piece that supports the light emitting unit and the light receiving unit. Can be easily changed, so that the time adjustment from the detection to the stop of the lowering of the driver's seat is facilitated.

According to the fifth aspect of the present invention, since the detection switch is always fixed at a predetermined position on the machine base without moving integrally with the luggage storage portion, the detection sensor and the control means are electrically connected. Simplifies wiring.

According to the sixth aspect of the present invention, the descent of the driver's seat can be resumed by the re-descent operation of the descent resuming means even when the detection signal is being output from the detecting means. Therefore, it is possible to restart the descent of the driver's seat at the discretion of the driver according to the situation, and to prevent the driver's seat from stopping at a high position and being unable to get off the driver's seat.

According to the seventh aspect of the present invention, since the key switch also functions as the descent resumption means, it is not necessary to newly secure a space for installing the descent resumption means.

[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 perspective view illustrating a relationship between a detection unit and a functional component room.

FIG. 4 is a partially cutaway side view showing an arrangement state of the detection means.

FIG. 5 is a schematic partial plan view of a picking forklift.

FIG. 6 is a hydraulic circuit diagram for a driver's seat lift cylinder.

FIG. 7 is a partially cutaway side view showing a detecting unit according to the second embodiment.

FIG. 8 is a hydraulic circuit diagram for the driver's seat lift cylinder.

FIG. 9 is a schematic plan sectional view showing a detecting means according to another embodiment.

FIG. 10 is a hydraulic circuit diagram for a driver's seat lift cylinder according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Picking forklift, 2 ... Machine stand, 6 ... Fork, 7 ... Driver's seat, 8 ... Functional parts room, 11 ... Driver's seat lift cylinder, 11a ... Bottom room, 22 ... Driver's seat up / down operation member Lever, 28 ... Luggage storage part, 2
9 detection means, 30 detection members, 31, 42 detection switch, 35b return line, 37 oil tank, 38
Solenoid valve, 39 ... solenoid valve control means as control means, 43
.., A control device constituting control means, 44, a key switch also serving as a re-lowering means, 45a, a light emitting section, 45b, a light receiving section.

Claims (7)

[Claims] 1. A fork and a driver's seat are independently movable up and down with respect to a machine base, and the fork is provided at a front part of the machine base and a functional parts room is provided at a rear part of the machine base. The upper part of the functional component room is formed in a shape in which an object can be placed, and a luggage storage part which rises and lowers integrally with the driver's seat is formed at the rear of the driver's seat so as to face the functional component room. In a picking forklift, a control valve for controlling the 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 elevating operating member for operating the control valve, and the driver's seat elevating operating member, An electromagnetic valve provided in a return line of a hydraulic circuit that connects a bottom chamber of the driver's seat lift cylinder to an oil tank in a state where the lower part is operated to a lower position, and an object mounted above the functional component chamber. Detect Possible detection means, and control means for opening the solenoid valve in a state where no detection signal is output from the detection means, and for closing the solenoid valve based on a detection signal of the detection means. Picking forklift equipped. 2. The control valve according to claim 1, wherein the control valve is a three-position switching manually operated valve. The control valve communicates the bottom chamber with a hydraulic oil supply pipe in response to an ascent, neutral, and descent operation of the driver's seat elevating operation member. The picking forklift according to claim 1, wherein the position is switched between a position where the bottom chamber cannot be communicated with the hydraulic oil supply line and the return line, and a position where the bottom chamber is communicated with the return line. 3. A detection member provided so as to be able to ascend and descend integrally with the luggage storage part and to be vertically movable below the luggage storage part with respect to the luggage storage part;
3. The picking forklift according to claim 1, further comprising a detection switch disposed above the detection member and outputting a detection signal when the detection member moves upward by a predetermined amount or more. 4. The light-receiving unit according to claim 1, wherein the detecting unit includes a light-emitting unit and a light-receiving unit provided on a support piece provided so as to protrude below a lower end of the luggage storage unit. The picking forklift described in. 5. The picking forklift according to claim 1, wherein the detection means is a detection switch that outputs a detection signal when a load equal to or more than a predetermined amount is applied to the upper side of the functional component chamber. 6. The control unit opens the solenoid valve again based on a re-lowering operation of the descent resuming unit even when a detection signal is output from the detecting unit.
The picking forklift described in. 7. The descent resumption means is also used as a key switch of a picking forklift, and the on / off operation of the key switch in the closed state of the solenoid valve is the descent resumption operation of the descent resumption means. Picking forklift.