JP2002059838A - Lift truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely move a lift truck forward and backward at a desired speed. SOLUTION: In this lift truck, an operating arm 13 is extended backward from a self-propelled truck body 3 having a lift 7 disposed in the front part, and the traveling direction of the truck body 3 is changed by swinging the operating arm 13 right and left. Handles 14A, 14B are mounted at the tip part of the operating arm 13 through a sliding mechanism 25 so as to be slidable in a fixed range forward and backward, and a potentiometer 17 to detect the sliding of the handles 14A, 14B is provided. Based on the detected signal by the potentiometer 17, the truck body 3 is advanced forward (a) or moved backward (b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lift truck capable of safely moving a low-lift type lift truck or the like forward and backward at a desired speed.

[0002]

2. Description of the Related Art FIGS. 8 and 9 show an example of a conventional low-lift type lift truck. It comprises a self-propelled truck body 3 having one drive wheel 1 and two caster wheels 2, said truck body 3
An electric motor 5 with an electromagnetic brake 5a for rotating the drive wheel 1 forward and reverse through a gear mechanism 4 is rotatably arranged around a vertical axis O, and a power switch 6 is provided on the upper surface of the casing 3a of the truck body 3. Is provided.

A pair of left and right lifts 7 are provided at the front of the truck body 3 so as to be able to move up and down, and a load wheel 9 provided at the end of each lift 7 via a swing bracket 8 is grounded to the floor F. The piston rods of the hydraulic cylinders 10 provided in a pair on the left and right sides in the truck body 3 are connected to the swing bracket 8 via a link mechanism 11.

Further, the casing 3a is
5b extending upward along the vertical axis O
An operation arm 13 is connected to the bearing 5b via a connection pin 12 so as to be vertically movable within a predetermined angle α (about 90 °). The handle 14 is provided in a protruding manner.
By rotating the drive wheel 1 about the vertical axis O via the electric motor 5, the traveling direction of the truck body 3 can be freely changed.

[0005] A pair of left and right operation rings 15 rotatably fitted to the distal ends of the handles 14 are integrally connected to each other via a connection shaft 16.
A rotary potentiometer (detector) 17 built in 4 is connected to one operation ring 15. Reference numeral 18 denotes a lifting spring that urges the operation arm 13 upward. Reference numeral 19 denotes a slight angle β between the upright state of the operation arm 13 (see the phantom line in FIG. 8) and the horizontal state of the operation arm 13 (see the solid line in FIG. 8). Brake switches 20 to 22 for detecting the state of being pressed down (about 3 °) and activating the electromagnetic brake 5 a are a lift button for raising and lowering and an emergency stop button, and are provided on the distal end surface of the operation arm 13.

In the above configuration, when lifting the load W, the power switch 6 is pressed to start the operation, and the operator M grasps one handle 14 and pushes down the operation arm 13 to a substantially horizontal state (solid line in FIG. 8). 10), the thumb Ma is inserted into the concave portion 15a of the operation ring 15, as shown in FIGS. Next, by rotating the operation ring 15 forward from the neutral position N by a desired angle, the electric motor 5 is rotated forward based on a detection signal from the potentiometer 17 for detecting the rotation, and the truck body 3 is rotated at a predetermined speed. After moving forward a and letting the lift 7 go under the luggage W, the lifting lift button 20 may be pressed. As a result, the hydraulic cylinder 10 is extended and driven, whereby the swing bracket 8 is
Is lifted, and the lift 7 can be lifted to lift the load W (see the phantom line in FIG. 8).

In order to transport the luggage W by moving the truck body 3 forward a, the operating ring 15 may be rotated from the neutral position N forward c by a desired angle in the same procedure as described above. When transporting the luggage W by moving the truck body 3 backward b, the operation ring 15 is moved from the neutral position N backward d.
Can be rotated by a desired angle. As a result, the electric motor 5 is rotated in the reverse direction based on the detection signal from the potentiometer 17 to move the truck body 3 backward at a predetermined speed.

In order to lift down the luggage W, the lowering lift button 21 may be pressed. As a result, the hydraulic cylinder 10 is driven to contract, whereby the link mechanism 11
The swing bracket 8 is tilted down via the, and the load 7 can be lowered by lowering the lift 7 (see the solid line in FIG. 8).

[0009]

In the above-mentioned conventional configuration,
For example, when the truck body 3 is moved backward b, the operation ring 1 is operated by the thumb Ma with the operator M facing backward.
5 (see FIG. 11), and it is necessary to operate the operation ring 15 in an unreasonable posture and in a state where it cannot be seen, so it is difficult to operate the operation ring 15 smoothly. When the running speed of the truck body 3 is too slow or too fast, it is difficult to maintain the running speed of the truck body 3 properly. In particular, when the running speed is too fast, the truck body 3 contacts the operator M. And there is a problem in safety.

An object of the present invention is to provide a lift truck capable of safely moving back and forth at a desired speed in view of the above-mentioned conventional drawbacks.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, an operation arm extends rearward from a self-propelled truck body having a lift disposed at a front portion thereof. In a lift truck in which the running direction of the truck body is changed by swinging the arm left and right, a handle is attached to a distal end portion of the operation arm via a slide mechanism so as to be slidable in a predetermined range in the front-rear direction. A detector for detecting sliding of the steering wheel is provided, and the truck body is moved forward or backward based on a detection signal of the detector.

According to the above construction, by pushing and pulling the handle and sliding it back and forth, the push / pull direction and the push / pull force of the handle are detected by the detector, and the truck body is pushed and pulled based on the detection signal. The truck can be moved forward or backward at a speed proportional to the force. In this case, since the forward / backward direction of the truck body and the pushing / pulling direction of the handle coincide with each other, the operator can easily move the truck body in a desired operating posture. It can move forward and backward smoothly at the speed. Therefore, for example, even when the operator moves the truck body backward while facing backward, the truck body can be safely driven so as not to contact the operator.

According to a second aspect of the present invention, in the first aspect of the present invention, the slide mechanism has a base plate provided at a distal end of an operation arm and a slide block provided at a base end of a handle. The slide block is fitted to the base plate via a slide guide so as to be slidable within a predetermined range, and the detector detects the slide of the slide block.

According to the above construction, since the handle side slide block is slidably supported on the operation arm side base plate via the slide guide, by pushing and pulling the handle, the handle is slid back and forth. The push / pull direction and the push / pull force of the handle can be accurately detected by the detector through the slide block. In addition, since the base plate of the slide mechanism and the slide block are integrally connected via the slide guide, the running direction of the truck body is reliably changed via the slide mechanism by swinging the handle left and right. be able to.

According to a third aspect of the present invention, in the second aspect of the present invention, a pair of front and rear springs which press each other with the slide block interposed therebetween are interposed between the slide block and the base plate. It is characterized by:

According to the above configuration, after the handle is slid forward or backward, the handle can be automatically returned to the neutral position by the pair of springs only by releasing the push and pull of the handle.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a pair of front and rear spring receiving seats are provided on the base plate with the slide block interposed therebetween. Protrusions are respectively arranged on the front and rear surfaces of the slide block so as to face each other. By engaging the ends of the pair of springs with the respective protrusions, the springs are moved between the spring receiving seats and the slide block. It is characterized by being interposed in.

According to the above configuration, the pair of springs can be reliably positioned by the protrusions provided on the pair of front and rear spring receiving seats and the front and rear surfaces of the slide block so as not to be displaced. Further, by arranging the projections facing each other at a predetermined interval, each projection can be provided with a function as a stopper that regulates the sliding range of the handle.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the detector comprises a potentiometer.

According to the above arrangement, the push-pull force applied to the handle and the push-pull direction can be accurately detected by the potentiometer, and the truck body can be moved forward or backward as desired based on the detection signal. .

[0021]

1 and 2 show a low-lift type lift truck according to one embodiment of the present invention, in which an operating arm 13 is rotatable about a connecting shaft 12. FIG. 13a, and a casing 13b having a substantially T-shape in a plan view and externally fitted to the distal end of the base frame 13a. A pair of left and right handles 14A and 14B are provided via a slide mechanism 25 provided in the casing 13b. A slide-type potentiometer (detector) 1 that is provided so as to be slidable in the front-rear direction and detects sliding of the handles 14A, 14B.
7 are provided. Since the configuration other than the above is substantially the same as the configuration shown in FIGS. 8 and 9, the same portions are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIGS. 3 to 6, the slide mechanism 25 includes a base plate 25 fixed to the distal end of the base frame 13a.
A, and a slide block 25B. The slide block 25B is slidably fitted to a slide guide 26 fixed on the base plate 25A along the front and rear directions e and f, and the base ends of the handles 14A and 14B. The part is fixed to both side surfaces of the slide block 25B through the opening of the casing 13b.

According to the above construction, the handles 14A, 14
Since the slide block 25B on the B side is slidably supported on the base plate 25A on the operation arm 13 side via the slide guide 26, by pushing and pulling the handles 14A and 14B, the front and rear directions e and f
The push / pull direction and the push / pull force of the handles 14A, 14B can be accurately detected by the potentiometer 17 via the slide block 25B that slides. Further, since the base plate 25A of the slide mechanism 25 and the slide block 25B are integrally connected via the slide guide 26, the handle 5A is swung right and left, so that the electric motor 5 is moved through the slide mechanism 25. Is rotated around the vertical axis O, and the truck body 3 is rotated.
The traveling direction of the vehicle can be reliably changed.

A pair of front and rear spring receiving seats 27a, 27 with a slide block 25B interposed therebetween on the base plate 25A.
b is erected, and a projection 28 is projected from the center of each of the spring receiving seats 27a and 27b and the front and rear surfaces of the slide block 25B. A pair of front and rear springs 29a and 2
9b, the spring 29
a and 29b are interposed between the respective spring receiving seats 27a and 27b and the slide block 25B.
a (or 27b), the potentiometer 17 is fixed, and the tip of the detection rod 17a of the potentiometer 17 is in contact with the slide block 25B.

According to the above configuration, the pair of springs 29a, 2
9b, the slide block 25B is positioned at the neutral position N. Therefore, when the handles 14A, 14B are pushed or pulled forward or backward f from the neutral position N, the pushing / pulling direction and pushing / pulling force are precisely determined by the potentiometer 17. And the handle 14
A, 14B can be released simply by releasing the push and pull.
9a and 29b allow the handles 14A and 14B to be automatically returned to the neutral position N. Further, since one of the spring receiving seats 27a is used for both the supporting operation of the spring 29a and the supporting operation of the potentiometer 17, the structure is simplified by the shared use, and the manufacturing cost is reduced.

As shown in FIG. 5, by arranging the projections 28 facing each other at a predetermined interval r, each projection 2
8 can be provided with a function as a stopper for regulating the sliding range of the handles 14A, 14B.

The operation of the forward / backward movement a, b of the truck body 3 based on the above configuration will be described. The handles 14A, 14B
When the push / pull operation is not performed, the slide block 25B is held at the neutral position N (see FIG. 4), and as shown in FIG. 7A, the protrusion length H1 of the detection rod 17a of the potentiometer 17 is reduced. It is set to an intermediate position, and the truck body 3 is stopped.

When the truck body 3 is to be advanced a from the above state, the operator M has only to grip one handle 14A (or 14B) and push it forward e. As a result, as shown in FIG.
As B slides forward from the neutral position N against the spring 29a, the detection rod 17a is pushed in, and its protruding length H2 is shortened, and is output from the potentiometer 17 in proportion to the pushing. The electric motor 5 is rotated forward at a predetermined speed based on the detection signal, and the truck body 3 can be advanced a at a desired speed. In other words, when pressed strongly, the rotation speed of the electric motor 5 increases and the truck moves forward, and when pressed weakly, the rotation speed of the electric motor 5 decreases and the truck moves forward slowly. Also, if the operator M stops, there is no pushing force, so the truck naturally slows down and stops.

When the truck body 3 is to be moved backward b, the operator M operates one of the handles 14A (or 1).
4B) may be grasped and pulled backward f. by this,
As shown in FIG. 7C, when the slide block 25B is moved rearward from the neutral position N against the spring 29b, the detection rod 17a is pulled out, and the protruding length H3 of the detection rod 17a is increased. The motor 5 is reversed at a predetermined speed based on a detection signal output from the potentiometer 17 in proportion to the pull-out, and the truck body 3 can be moved backward b at a desired speed.

According to the above configuration, the handles 14A, 14
By pushing and pulling B and sliding it back and forth, the pushing and pulling directions and pushing and pulling forces of the handles 14A and 14B are detected by the potentiometer 17, and the truck body 3 is moved at a speed proportional to the pushing and pulling force based on the detection signal. To advance a or reverse b. In this case,
Forward and backward a and b directions of the truck body 3 and the handle 14
Since the push-pull directions e and f of A and 14B coincide with each other, the operator M can smoothly move the truck body 3 forward and backward a and b at a desired speed in an easy operation posture. Therefore, for example, even when the operator M moves the truck body 3 backward b while facing the rearward f, the truck body 3 can be safely driven so as not to contact the operator M (see FIG. 1).

In the above embodiment, the push / pull of the handles 14A and 14B is detected by the potentiometer 17, but the invention is not limited to this. Instead of the potentiometer 17, various detecting devices such as a load cell are used. May be used.

[0032]

According to the first aspect of the present invention, by pushing and pulling the handle and sliding it back and forth, the push-pull direction and the push-pull force of the handle are detected by the detector, and based on the detection signal, The truck body can be moved forward or backward at a speed proportional to the pushing / pulling force. In this case, the forward / backward direction of the truck body and the pushing / pulling direction of the steering wheel match, so that the operator has a comfortable operating posture. Thus, the truck body can be smoothly moved back and forth at a desired speed. Therefore, for example, even when the operator moves the truck body backward while facing backward, the truck body can be safely driven so as not to contact the operator.

According to the second aspect of the present invention, since the handle side slide block is slidably supported on the operation arm side base plate via the slide guide, the handle is pushed and pulled to interlock with it. The push / pull direction and push / pull force of the handle can be accurately detected by the detector via the slide block that slides back and forth. Also, since the base plate of the slide mechanism and the slide block are integrally connected via a slide guide, by shaking the handle left and right,
The running direction of the truck body can be reliably changed via the slide mechanism.

According to the third aspect of the present invention, after the handle is slid forward or backward, the handle is automatically returned to the neutral position by a pair of springs only by releasing the push and pull of the handle. Can be.

According to the fourth aspect of the present invention, the pair of springs can be reliably positioned so as not to be displaced by the projections provided on the pair of front and rear spring seats and the front and rear surfaces of the slide block. Further, by arranging the projections facing each other at a predetermined interval, each projection can be provided with a function as a stopper that regulates the sliding range of the handle.

According to the fifth aspect of the present invention, the push / pull force applied to the handle and the push / pull direction can be accurately detected by the potentiometer, and the truck body is moved forward or backward as desired based on the detection signal. Can be done.

[Brief description of the drawings]

FIG. 1 is a side view of a lift truck according to an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a side view of the main part.

FIG. 4 is a plan view of the main part.

FIG. 5 is an enlarged horizontal sectional view of the main part.

6 is a view as viewed in the direction of arrows BB in FIG.

FIGS. 7A to 7C are explanatory diagrams illustrating a detection operation.

FIG. 8 is a side view showing a conventional example.

FIG. 9 is a plan view of the same.

FIG. 10 is an enlarged plan view of the main part.

FIG. 11 is a view as viewed in the direction of arrows AA in FIG. 10;

[Explanation of symbols]

 3 Truck body 7 Lift 13 Operation arm 14A, 14B Handle 17 Potentiometer (detector) 17a Potentiometer detection rod 25 Slide mechanism 25A Base plate 25B Slide block 26 Slide guide 27a, 27b Spring receiving seat 28 Projection 29a, 29b Spring a Forward b reverse

Claims (5)

[Claims] An operation arm extends rearward from a self-propelled truck body having a lift disposed at a front portion, and the traveling direction of the truck body is changed by swinging the operation arm left and right. In the truck, a handle is attached to the distal end of the operation arm via a slide mechanism so as to be slidable in a predetermined range in the front-rear direction, and a detector for detecting sliding of the handle is provided. A lift truck, wherein the truck body is moved forward or backward based on a signal. 2. The slide mechanism has a base plate provided at a distal end of an operation arm and a slide block provided at a base end of a handle, and the slide block is connected to the base plate via a slide guide. The lift truck according to claim 1, wherein the lift truck is fitted so as to be slidable within a predetermined range, and the slide of the slide block is detected by the detector. 3. The lift truck according to claim 2, wherein a pair of front and rear springs which press each other with the slide block interposed therebetween are interposed between the slide block and the base plate. 4. A pair of front and rear spring receiving seats protrude from the base plate with the slide block interposed therebetween.
Protrusions are respectively opposed to each of the spring receiving seats and the front and rear surfaces of the slide block, and by engaging the ends of the pair of springs with the respective projecting portions, the springs can be moved to the respective spring receiving seats. The lift truck according to claim 3, wherein the lift truck is interposed between the lift truck and the slide block. 5. The lift truck according to claim 1, wherein the detector comprises a potentiometer.